♪♪
-We're going to get started.
Our first speaker is Erin Wirth.
She's with the USGS based out of the University of Washington,
the Department of Earth and Space Sciences.
She's a geophysicist by training,
and she works on strong ground motions,
and she's going to be talking tonight
about general earthquake science here in Western Washington
and the Puget Lowland and earthquake hazards in general.
So, Erin, please come up.
-Can you hear me.
Okay. Is this a good volume?
Great.
Well, thank you very much for coming tonight.
So as Brian said, I'm going to kick off the night
by giving you an overview of the different types of earthquakes
that we have here in the Pacific Northwest,
and then I'm going to try to tell you
a little bit about the current research
that's being done into two types of these earthquakes,
so I'll tell you a little bit about a project
that's in its very early stages
and a project that's getting towards its end.
So many of you may have seen this cartoon before,
so this is a figure that we show a lot
because it does a nice job
illustrating the tectonics of the Pacific Northwest,
so the Cascadia Subduction Zone is a 1,000-kilometer-long fault
that extends from British Columbia
all the way down to Northern California,
and here, we have the Juan de Fuca Plate
subducting beneath the North American plate,
and we're capable of getting three different types
of earthquakes in the Pacific Northwest,
so the first type are crustal earthquakes,
so these happen in response to crustal deformation.
Some of the big ones that you might have heard,
there was a Seattle fault earthquake
sometime around the year 900 AD.
There was also a large earthquake in Eastern Washington
in 1872.
The second type of earthquake that we often talk about
are these deep earthquakes, so these are earthquakes
that occur in the subducting Juan de Fuca plate,
and these are our most frequent types of earthquakes,
so the one you might remember is the 2001
Nisqually earthquake.
There was also one in 1965
and then one in 1949 before that.
And then finally, the third type of earthquake
that I'm going to be talking about tonight
are subduction zone earthquakes,
so these are earthquakes that occur when this red area,
this red area that's outlined in red, slips,
so when the subducting Juan de Fuca Plate
slips past the North American plate,
and these are very large earthquakes,
so generally magnitude eight or magnitude nine,
and the last one of these that occurred in the Pacific
Northwest happened in the year 1700,
and we know that from looking at the geologic record
and also from oral tribal records.
Okay, so we know that the Cascadia Abduction Zone
is capable of having these three types of earthquakes,
but how frequently do they occur?
So we generally think of these probabilities
in terms of how likely these earthquakes are to occur
within the next 50 years, so I'm in my early 30s.
I often think of this as, "This is the percent chance
of one of these earthquakes happening in my lifetime."
So for a crustal earthquake, we generally say
there's about a 15 percent chance of a magnitude 6.5
or above happening in the Puget Sound region,
but I am going to show you a new project later
that Brian Sherrod is doing that might be changing
how we think about this number.
Deep earthquakes, remember,
I said these are our most frequent,
so we say that there's an 84 percent chance
of one of these happening in the next 50 years,
so they're pretty common.
And finally, the subduction zone,
the magnitude nine earthquakes,
so we know, again, from that geologic record
that they happen roughly every 500 years or so,
so we estimate that that means
that there's about a 14 percent chance
of one of those happening in the next 50 years,
and this is about 5,000 times larger
in terms of energy release than these 6.5s.
So another way to think of these earthquakes
and to understand the difference between them is
to look at maps of shaking
that we would expect from them, so on the left,
this is a shake map from the magnitude 6.8 2001
Nisqually earthquake,
so this is showing you the areas in Washington
that experienced shaking during that earthquake,
so you can see here that a large swath of the Puget Lowland area
is kind of in this orange and yellow,
so that's very strong to strong ground-shaking, okay,
and it affected -- You can even see light shaking
throughout most of Washington and Northern Oregon.
So if we look at -- This is now a hypothetical shake map, okay,
so we haven't seen a large earthquake
on the Seattle fault in our lifetime,
so this is what we would estimate what it would be like,
so here you see that there's stronger ground
shaking along the fault,
so the Seattle fault is right about here where I'm pointing,
so in that area, we experience severe to violent shaking,
and then the shaking decays as you move further away.
So what about one of those magnitude nine earthquakes?
So this was a deep earthquake.
This was a crustal-fault earthquake.
How do the magnitude nine earthquakes compare?
So this is a shake map for, again,
a hypothetical magnitude nine earthquake.
You can now see that this red area,
so this severe, this violent shaking,
is now everywhere along the coast
and that's because, remember, the Cascadia megathrust extends
everywhere along the coast, and as we would expect,
that shaking gets lighter as we move further inland.
And so the big difference here is that this is affecting
a much wider area than the other types of earthquakes,
so here, you're experiencing strong shaking from Canada
all the way down to Northern California.
Okay, so for the remainder of this talk,
I'm going to talk to you about two projects
that are trying to study crustal-fault earthquakes
in the Puget Sound region and magnitude nine earthquakes
on the Cascadia megathrust.
So as I mentioned, these Nisqually-style earthquakes,
we see them more frequently.
We think we know.
We understand them a bit better.
We know how to prepare for them a bit better,
but for these earthquakes that we haven't seen in our lifetime,
we need to follow other...
We have to look for other options to learn about them,
so we either need to look at the geologic record,
or we need to maybe do supercomputer simulations,
so I'll show you a previous
of what that looks like in a minute.
Okay, so first, I'm going to talk about this project
that looks at shallow crustal earthquakes
in the Puget Sound area,
and this is work that's been done by
Brian Sherrod, Richard Styron and Stephen Angster of the USGS.
So one of the goals of this study,
which is still in its preliminary stages,
is to constrain the earthquake recurrence and magnitude
for Puget Sound-area crustal earthquakes,
so this is a map showing the major
Puget Sound area faults, and this gray box here
is meant to denote the region that they're studying.
So one of the questions that they're trying to answer
with this new study is, what is the estimated magnitude
of previous earthquakes that have occurred in the
Puget Sound region?
So one of the things that they're doing is,
they're looking at fault offsets,
so how much the fault has moved in the past,
and to do this, they can dig trenches across faults.
They can look at scarp profiles, and they can look at how much
the paleo earthquakes uplifted shorelines,
and so this can give them an idea
for how much the fault moved,
and a lot of the estimates that they're seeing
are between 0.5 and 8 meters,
so another thing that they need to look at in order to estimate
the magnitude of these earthquakes
is how long the fault is,
so recently, we now have a lot of these beautiful lidar images,
which are just a surveying technique
that let you see the topography of the surface,
and you can see here, there's a...
You can see for evidence of the Seattle fault,
so you can trace these faults in the lidar images,
and you can estimate their length.
So the estimates that they're making in this project,
so far they're seeing fault lengths that range from 1
to 30 kilometers in the lidar images,
but they could be longer.
Some of these fault scarps could be difficult to see.
So using these two things, so how long the fault is
and how much they think the fault moved,
they can estimate a magnitude for what these earthquakes,
how big these earthquakes were in the past,
so this image might be a little bit hard to see,
but this is showing magnitude on the bottom axis,
and these are all different paleo earthquakes
that they see in the geologic record,
and where these humps
are are the most likely magnitude of those earthquakes,
and so they're seeing magnitude estimates for earthquakes
in the Puget Sound area that are between 6.4 and 7.5.
Okay, so then the question becomes,
how often do these earthquakes occur?
And so this image here is showing earthquakes
that they're finding and how many years
before present those earthquakes occurred,
and these are in thousands of years,
so this is 2,000 years ago, 4,000 years ago, et cetera.
And so these bars are color-coded,
so each bar is an earthquake, and the colors are color-coded
to denote which fault they occurred on,
and the way to read these bars is that the center of the bar
is the most likely age for the earthquake,
and the tails of the bars are possible ages, but less likely.
So if we count these up, they estimate that there's been
27 of these large earthquakes in the Puget Sound area
in the past 16,000 years.
However, if you just look at the past 4,000 years,
so this cluster right here,
there's been about 21 earthquakes
in the past 4,000 years, so the recurrence interval,
so how frequently do these earthquakes occur,
over the past 16,000 years is 400 years.
Again, if we just look at this most recent segment,
they're happening about roughly every 200 years.
Okay, so this is how we are starting to refine
those estimates
for how frequently we might expect large crustal earthquakes
to occur in the Puget Sound region,
and I'm sure Brian will update you
as this work progresses in the future.
Okay, so now I'm going to finish up
by telling you a little bit about a project
that's a little bit further along to study Cascadia
megathrust earthquakes,
so these are those large earthquakes
that occur along the megathrust fault offshore.
So recently, we had a 6-year, $3 million collaboration
between the University of Washington,
which is NSF funded, and the US Geological Survey.
We called it the M9 Project,
so M9 stands for magnitude nine earthquake,
and the goal of the M9 project
was to reduce the catastrophic potential of Cascadia
megathrust earthquakes through advances
in hazard assessment and adaptive planning,
and I'll tell you what that means in a minute.
So this is a schematic of our M9 project,
and so my role in the project was up here,
so we ran 50 different computer simulations
of magnitude nine earthquakes
that could occur in the Pacific Northwest,
so these are hypothetical earthquakes,
and we really wanted to see the range of possibilities
for different scenarios,
so what is the best-case scenario?
What is the worst-case scenario?
And then we would take those supercomputer simulations,
and we passed them onto people
who were studying tsunami generation,
the impact of ground-shaking on buildings and infrastructure
as well as the generation of liquefaction and landslides.
And then finally, we had some social scientists on the project
that are trying to understand and study,
how do we now present all this information to communities
in a way that is useful to them?
So as I mentioned, we ran 50 different computer simulations
of magnitude nine earthquakes.
This is an example of one of those simulations,
so you see the earthquake starts here at the hypocenter.
Seismic waves radiate out, so the entire megathrust
is going to rupture in this scenario.
Here you see shaking has arrived at Crescent City.
These wiggles represent shaking.
Shaking has arrived at Portland, La Grande and Seattle.
I'm going to play that one more time
and point out a few things, so again, we have seismic waves
radiating outwards from the hypocenter.
Seismic waves are starting to reach Portland.
They're just about to reach Crescent City
and La Grande and Seattle,
and so two things that I'll point out here,
and then we'll talk a bit more about the detailed results,
but one is that you'll notice Crescent City
has much strong shaking than some of these other areas,
and that's because Crescent City is on the coast.
It's a lot closer to that megathrust fault offshore,
so it'll experience strong ground shaking.
Now, the other interesting thing,
and I'm going to talk about this in detail,
you'll notice that even though Seattle and La Grande
are the same distance, so they're the same distance
away from the megathrust fault offshore,
Seattle has much strong ground shaking
than La Grande, and that's because
Seattle sits within a deep sedimentary base,
and that amplifies ground shaking,
so let's chat a bit more about that.
So one of the major results of this project
was that local geology is going to significantly impact
the strength of your ground-shaking,
so as I just mentioned,
Seattle sits within a deep sedimentary basin.
One analogy that we like to use
is that this is like a bowl of Jell-O,
so if you shake the bowl of Jell-O
because the Jell-O inside is so weak,
it'll shake much more than the bowl
or the plate that it's on.
So this is just a little schematic,
seismic waves entering the sedimentary basin
and amplifying as they enter the basin,
and it's not just the sedimentary basin,
but also shallow soft soils
will also amplify your ground-shaking,
so both of these things matter.
So this is just an example just to show you
about how shallow soft soils will amplify ground-shaking,
so this a figure from Kathy Troost
at the University of Washington,
and this map here is showing, in colored areas,
the thickness of artificial fill,
or holocene alluvium, sediment, so this is very weak material,
and so in addition to being in the basin
and having the basin amplify your ground-shaking,
these areas will also have more amplification on top of that
because of their shallow soft soils.
Okay, so this is a geologic map of Washington,
and I don't expect you to be able to see
all these different things,
but I just want to point out that this yellow color here
is sediment, so the Puget Lowland,
even though not everywhere in the Puget Lowland
is in a deep sedimentary basin like Seattle is,
it still has some sedimentary material at the surface,
and so this is going to amplify ground-shaking
in that entire area.
So I'm going to, in a minute, zoom in on
one of our supercomputer simulations in this region,
but first, I just want to point out,
so this is the Puget Lowland.
I just said we have sedimentary material at the surface,
but then we also have these deep basins, so this map here,
I know it's a little hard to orient yourself.
Seattle is right around here,
and everywhere that you see dark blue,
or most places that you see dark blue,
is a sedimentary basin,
so there's a basin beneath Everett.
There's a basin beneath Seattle.
There's a basin beneath Tacoma, so everywhere.
So this is one of the results
from our M9 Project supercomputer simulations,
so this is showing long period shaking
that's going to impact tall buildings,
and so what I'm showing you here
is shaking intensity at a period of 3 seconds,
so this is shaking that would impact
maybe a 30-story building, so fairly long period.
So everywhere you see red color is stronger shaking.
Everywhere you see light color is weaker shading,
and you can see that the entire Puget Lowland is lighting up
compared to areas that are not in the Puget Lowlands,
so areas on the Olympic Peninsula are white,
and the Seattle basin and the Tacoma basin
are lighting up even the most,
and that's because of those deep sedimentary basins.
Okay, so the second outcome of this magnitude nine project
is that there are a range of possibilities, okay?
So I mentioned we ran 50 different computer simulations,
and there was a wide range of shaking intensities,
and so part of the reason for this
was because we varied a number of different rupture parameters,
so when we ran these supercomputer simulations,
we varied the hypocenter location,
so that's where the earthquake starts,
so sometimes we had it start in the north.
Sometimes we had it start in the south.
Sometimes we had it start in the middle.
We also varied the inland rupture extent,
so that's how close the rupture gets to Seattle,
and finally, we also varied the location
of these strong patches on the fault,
so there's certain patches on the fault
that seem to radiate the strongest ground-shaking,
and so their location matters, so we also varied that.
So given that I don't have a ton of time,
I'm just going to show you an example of what happens
when we vary the hypocenter, so where the earthquake starts,
and so this is the most technical I'm going to get,
so bear with me for a second,
but the reason why this hypocenter location matters
is because of something called rupture directivity.
So rupture directivity refers to a phenomena
where earthquake ground-shaking is strongest
in the direction of fault rupture,
so you can kind of think of this like a Doppler effect.
You know how an ambulance sounds different
when it's coming towards versus when it's going away from you?
That's similar to what's happening here.
So I tried to draw you a schematic,
so this black line here is a fault.
Let's say an earthquake starts on the fault
at this yellow star,
and then I'm going to say the fault is unzipping
in this direction towards the right,
so that means that anything in front of that direction,
so towards the right, will experience stronger shaking
as these seismic waves pile up on their way in that direction,
and areas behind the unzipping of the fault
will experience weaker shaking.
So let's look at two different
magnitude nine earthquake scenarios.
So for scenario A, so everywhere -- so this is --
I should explain this first.
So everywhere you see color is a spot
on the megathrust fault that's going to move, okay?
And it's going to the hypocenter location is where this star is,
so the earthquake will start here for this scenario,
and then it'll unzip in all these directions,
so to the south, to the west, to the north,
but you'll notice that it's going to be
directed away from Seattle.
So for scenario B, so this is...
They're both magnitude-nine earthquakes,
but in this case, the hypocenter starts pretty far offshore,
so it's going -- And it's also to the south,
so the earthquake rupture is going to unzip to the north,
to the east and to the south, so you'll notice now
that it's unzipping in the direction towards Seattle.
So let's look at what the ground-shaking would look
like in each of these scenarios.
Whoops. Okay.
So this is for shaking recorded,
hypothetically recorded, at a site in Seattle,
so this is the velocity of the ground-shaking over time,
and these are both to the same scale,
so both magnitude nine earthquakes to the same scale,
same location in Seattle,
but you'll notice that the shaking in this scenario
is about four times greater
just because we changed where the earthquake starts,
so where the earthquake starts makes a big difference
in terms of the ground-shaking you might experience.
So I do want to briefly touch on other project,
so I did mention, I'm a seismologist.
I worked on these supercomputer simulations,
but there are a lot of other pieces
to that M9 project that are also happening.
So we have some folks at the University of Washington
that are now taking our hypothetical ground motions,
and they're putting them through their building models.
This is exaggerated, just so you know.
We also have people
that are looking at the potential for landslides,
so they look at the slopes that already exist in Seattle,
and then they take into the account the ground shaking
that we're predicting,
and everywhere you see color here, so it's me.
This is West Seattle. This is where I live.
So everywhere you see color, so on these steep slopes,
are areas where they would predict landslides to be likely.
We also have people that are doing tsunami simulations,
so as we know from the 2011 Tohoku earthquake
and the 2004 Sumatra earthquake, the tsunami is often --
has the greatest impact of loss-of-life,
so we also have people that are doing simulations
of tsunami generation and inundation.
And then finally, I did mention
that we have some social scientists on the project,
so they're taking some of the results.
This is an example where they're taking some tsunami
simulations to local communities,
so this is a workshop that they had in Aberdeen,
Washington to try to show the communities
these different possible outcomes
and discuss community planning for future.
Okay, and so I'm done.
I think we're going to hold questions to the end,
but thank you very much.
[ Applause ]
-Okay, thank you, Erin.
That was great.
Erin is going to cue up our next talk.
And you can probably hear me okay --
Well, I'll speak into this microphone.
So our next speaker is Harold Tobin.
Again, he's the state seismologist.
He's based at the University of Washington,
and he's a geologist/geophysicist.
I guess he couldn't make his mind up,
and again, he's based at the seismology lab at Earth
and Space Sciences at UW,
and I do want to mention that he's recently come to us
from the University of Wisconsin,
and I was teasing him earlier
that he's finally come to the real UW.
Okay, and Harold is going to talk to us about monitoring,
seismic monitoring in the Pacific Northwest,
including the new planned earthquake early-warning system
that they're building out in the Northwest.
Harold? -Thank you.
And of course, it's not true.
I came to the real U-Dub, and the other one is UW,
and that's the difference.
Yeah.
But, yeah, I'm actually really happy to be in Seattle
and so happy that all of you came out tonight
to listen to us talk about these things.
I'm going to take a step back from now
that Erin has kind of scared you
about a lot of the potential scenarios
and take a big-picture look at the subduction zone
and then segue that into talking about earthquake early warning,
as Brian just said.
So, you know, we literally inhabit the subduction zone,
right, and it is the thing
that makes this place a beautiful place to live,
and we live in the shadow, literally sometimes,
of volcanoes that are directly related to the existence
of the plate tectonic system,
the activity of the subduction zone.
We can look out the other way from the city
and see the Olympic Mountains,
and if you take a perspective on the Olympics,
you know, from offshore looking in towards the coastline,
actually, I got my start as a researcher in this field
as an undergraduate field assistant to one of my profs
working two summers in the Olympics,
spending 35, 40 days in the backcountry up
there high up in the mountains.
Those mountains are literally there, you know,
because of tens of thousands, hundreds of thousands,
millions of earthquakes that have slowly uplifted them
earthquake by earthquake by earthquake,
and maybe that's a daunting thought in a way,
but to me, it just says that we choose this place to live,
or we are here in part
because the Earth is so alive in our region,
and that's something to both embrace
and recognize the natural hazard from,
and when we look at a view like this,
we can recognize too that this system that affects us on land
but has equally sort of complex
and interesting geology offshore,
and you look out there, and hopefully,
I can figure out which one of these buttons is the laser.
Maybe that one. There we go.
You look out there, and you can see all these,
maybe these sort of lines or these things like
that look like worms marching northward,
and they're literally like the folds in the carpet,
meaning the Juan de Fuca Plate
that's going down underneath our feet, you know, look down.
Thirty miles straight down, right, is that subducted thing
that used to be the sea floor of the Pacific Ocean off our coast
but has transferred underneath our feet
and the North American continental plate,
and it folds up the layers of sediment
and scrapes them off that were sitting out here
on top of the subduction zone.
The part that Erin has just told you about,
where the fault zone is actually underlies
all of this region mostly offshore.
A little bit onshore, but an awful lot of that fault
is actually the offshore part,
so we literally inhabit the subduction zone.
Of course, that comes with this cost,
and we've already talked a little bit
about these earthquakes and the deep-slab earthquakes,
the ones that are down there in that chunk
of the former seafloor
of the Pacific Ocean that's below our feet,
are the ones that we're most likely to experience
in the future, as Erin just showed you,
and that we've experienced in the past,
and, you know, 2001 was 18 years ago,
the last really strongly felt earthquake.
Of course, we had a little reminder this summer.
How many people were woken up by the 4.6 in Monroe in July?
Yeah, I was.
I had just gotten off a plane in Japan
for a research meeting over there,
so my phone started buzzing like crazy with the news media
and stuff asking me questions,
and I was sort of having dinner and a beer in Japan,
so I couldn't answer very directly.
But our region is an earthquake-prone region,
and so I'm going to show you just basically the summation
of 40 years of the data
that the Pacific Northwest Seismic Network has collected.
Actually, this beautiful visualization was created
by our fantastic colleague, Nathan Becker,
at the Tsunami Warning Center,
but it's going to show you our region.
Dates are going by up here in the corner, so there's 1980.
We're just going month by month.
The size of the circles is scaled
by how big the earthquakes are.
You can see the scaling right there, right?
And then they're just going to appear,
and then they're going to slowly fade away,
and depth is the color,
so you can see big earthquakes and little ones,
and we constantly have earthquakes in our region.
There are tens of thousands of earthquakes
over what we call our earthquake catalog,
and they also occur in patterns
that we recognize as specific areas.
So offshore, actually we see a lot of earthquakes
at kind of the southern end
and northern of this Juan de Fuca Plate
where it kind of meets a couple of other plates,
and they're breaking up and jostling at their edges,
and then we also see them along what's called the Blanco
Transform Fault, a strike-slip fault
much like the San Andreas down here.
Northern California, Southern Oregon
had a lot pop off in the 1990s,
but meanwhile, we're seeing kind of a constant background,
and of course, we don't feel the vast majority
of these earthquakes that happen in the Puget Sound region.
Oregon is pretty lucky. It just stays really...
Well, Oregon is really boring is another way
I'll put it, to a seismologist, but, you know,
it has a lot less going on down there.
What I'm going to do is actually jump this ahead a little bit.
There's so much interesting stuff
in all the time that's available.
The question is, can I?
[ Speaking indistinctly ]
Maybe I can't.
Maybe I can't see it well enough.
It's down there, but okay.
So that was Nisqually, right, December 2001,
and it's close enough now.
We'll let it run out a little bit.
So our main locuses of earthquakes
are actually those crustal or slab earthquakes right under the
Puget Sound region, and that's why a lot
of the concentrated monitoring has been there.
These distant offshore ones, even though they're pretty large
and pretty frequent, really don't present a hazard onshore.
They're not tsunami sources, and they're also too far away
to create a lot of shaking onshore
from these events out here.
Now notice what's missing, right?
We just don't see anything in that part
where Erin just told us was the potential magnitude
nine earthquake all in that area.
We see it all filling in further in underneath our feet
or much further offshore but not in the part
that we think of as this critical megathrust zone.
So I'll call that the dog
that hasn't barked in the night, right?
In the entire time we've been recording earthquakes,
there's been barely anything at all,
even down at low magnitude levels,
on the Cascadia Subduction Zone.
Erin already told you about the probability,
so I won't go over that now,
but we know that it is actually locked up and ready
to produce the next earthquake for a number of reasons,
and one is, we can actually literally measure
the way the strain is accumulating in the crust
using very sophisticated GPS measurements
and other things that tell us
how the two plates are locked together,
but also we know that there was this event in 1700.
And you've probably heard
this story already because you're all here
because you're interested, at least, in earthquakes,
but, you know, it's the best piece of geosleuthing,
I think, of all time basically that Brian Atwater
from USGS here in Seattle at U-Dub,
David Yamaguchi, Kenji Sataki and others did together,
and, you know, they knew that there were the legends
from the indigenous native tribes along the coast
that big events had happened,
flooding villages and strong shaking.
They discovered that there were all kinds of deposits
that came from the actual tsunami in the coastal regions
over the top of topsoil,
suddenly both sands that came from the tsunami
and then mud on top that showed that the land
had been dropped down and in fact killed all the trees
all of a sudden in these ghost forests,
and the tree ring dating showed not only the year
that that took place but even the season, the wintertime.
But we know it even better than that because the group,
the historians in Japan, were aware of this tsunami
that had no earthquake associated with it,
the ghost tsunami or the orphan tsunami of that year, 1700,
and there were lots and lots of very detailed
historical accounts of the damage done
by a tsunami with no known earthquake,
and by computer simulations of what it would have taken
to inundate the Japanese exactly that way,
the conclusion was drawn that only a magnitude nine earthquake
coming from this portion,
the Pacific Northwest region of the Northern Pacific,
could've produced the tsunami that accounts for all that,
so it actually gives us the date and time,
you know, literally down to the individual day,
and people in the room who know about this
will know that I have a typo on there.
I can't believe I forgot to fix that
since the last time I used that slide.
January 26th is the correct day, right?
So our region is an earthquake region, and we know it,
and so, you know, when you think about earthquakes,
they don't happen very often,
so we don't think about the losses from them all that often,
but this FEMA's estimate of the annualized,
meaning if you average out even things that don't happen
for decades and decades, the cost associated with them,
you get really significant numbers.
Most of the earthquake hazard for the US is on the West Coast.
A large, large fraction of that is in California,
but something like 700 million per year
when you average out earthquake losses over time
is in our region up here,
so we really have to be thinking about all this
and thinking about, what can we do to mitigate it?
And my argument, of course, as a person who works on this,
is that we don't spend nearly enough money
on all sorts of mitigation
because the annualized costs potentially are so large,
so that's led to the work of the Pacific Northwest
Seismic Network, and my predecessors here.
You heard I just got here a year ago,
so I can claim much credit for the PNSN.
Paul Bodin, who's the network manager for PNSN
is here now, Steve Malone, who's the former director of the PNSN
and was famous for warning all of you
about Mount Saint Helens back in the 1980
did a lot to make this happen.
We now have hundreds of seismic stations
that are contributing data all the time,
real-time data feeding into our computers,
into our network at U-Dub
and allowing us to rapidly calculate
how big an earthquake was, where it's located,
how it might be aligned with particular faults
or parts of the plate tectonic system that we do
or don't know about,
and now also allows us to do this kind of not just fast
but even real-time earthquake early warning
that I'll tell you about in a minute.
And our hosts tonight, the USGS, are our big funding source
at U-Dub so we can operate this seismic year.
We're in our 50-year anniversary right now in 2019.
So, you know, our mission is reducing
the impacts of earthquakes and eruptions
by providing the information, and that's one component of that
is what we're doing right now, right?
And our job is also to monitor ground motions
and ultimately now,
a big thing that's become kind of the exciting new thing
and also the big activity for us in recent years
and right now is operating this shake alert earthquake
early-warning system.
So I'll talk a little bit about what earthquakes
are because to understand earthquake early warning,
we have to think about this.
We experience an earthquake as shaking, right?
The ground is shaking for us,
and that's we feel, but the earthquake itself,
as Erin just kind of really made very obvious,
is the slip that happens on the fault,
so as the two sides of the fault that are storing up that strain,
they're frictionally stuck together just like, you know,
if you have a heavy piece of furniture
that you can't push across the floor
because of the friction holding it down to the floor,
but when the stresses that accumulate from plate tectonics,
from the push of the plates, overcomes that, it breaks,
and it slips along this kind of rough surface.
It's really hard to point from these high angles over here.
Maybe the pointer is just dying on me.
It slips along that rough surface,
and as it chatters along is radiating those seismic waves
just like noise, you know,
when you push that piece of furniture,
and suddenly it goes across the floor.
The seismic waves are something like that.
Unlike sound waves,
seismic waves radiate in a couple of different modes,
and so there's what we call the P waves and the S waves,
P for primary or first and S for secondary
and then the surface waves that follow them,
and this thing called PGA means peak ground acceleration,
so the part of the shaking that has the highest amplitude
and does the most damage.
The key thing for us that we'll see in a few minutes
is that those P waves come first,
and they tend not to be damaging,
but they get to a sensor very quickly,
and they're followed by these much slower
but more damaging waves that come later.
All right. So zooming back out then,
we can see, well, these subduction zones
are not just the Pacific Northwest.
There are actually lots of places around the world.
That's a partial list, and they all share some common features,
so now we kind of understand that that plate that's coming in
is going down beneath our feet.
Eventually, when it gets quite deep,
it's so deep that it starts the melting process
that fuels our volcanoes, so, you know,
we have this subduction process to thank
for all of the volcanoes that we enjoy being near
and also worry about a different hazard
we're not talking about tonight, right?
But the part that's shallower is not so hot, and so it's colder,
and that's where the plates can get stuck together
and ultimately create that earthquake
that then ruptures out and along the subduction zone
and crucially takes this portion that was stuck together
and sort of pulled back almost like an archer
pulling a bow back for the hundreds of years
in between earthquakes, right, accumulating that strain
at a rate of just a couple of inches a year.
About the rate your fingernails grow is a way to think about it,
so let your fingernails grow for 300, 400 years,
and you've got many, many tens of feet,
dozens of feet of accumulated missing slip,
and all of a sudden, that goes.
And when that displaces the sea bottom,
it also is the thing that launches the tsunami
that pushes the water up
in exactly the same way it pushes the sea bottom up,
and then the tsunami goes,
so that's the geology 101 portion of this evening
right there is the diagram.
The uplift of the sea bed is the cause of the tsunami,
and we know, of course,
that for subduction zone earthquakes in our experience,
the tsunamis are almost always actually,
when they're generated, at least,
the largest hazard from the subduction earthquake,
and that was probably true in 1700
for the people who lived along the coast.
That's a photo from Tohoku, Japan in March,
2011 during that very large tsunami,
and it was, you know, a shocking moment for all of us,
right, seeing all that stuff, especially the live footage
that was coming in on television and everything at that time,
but I want to not just say,
these events are so overwhelming,
and I think a lot of people who read that New Yorker
article just thought, "They're so overwhelming.
There's nothing we can do about them. Everything is gone.
Everything west of I-5 will be toast,"
is the quote from the New Yorker article,
and it's actually kind of a missed quote anyway
because what FEMA was really trying to say was everything...
We have to plan as if everything west of I-5 could be toast,
or anything west of I-5, and they didn't even mean I-5.
They really meant west of the Puget Sound,
Puget Lowland region, you know,
but to think about how all this happens
is to recognize that in this disaster,
which was one of the hugest subduction
zone earthquake disasters,
19,000 people lost their lives, virtually all of them,
by the way, from the tsunami and not from the earthquake,
and that's partly because of the excellent preparedness in Japan,
building codes and life-safety structures,
so subduction-zone earthquakes are eminently survivable, right?
And even the tsunami,
you can look at it a couple of different ways.
Nineteen thousand people lost their lives.
At the moment of the earthquake,
350,000 people were in the death zone of the tsunami,
so that means 94 percent of the people escaped,
and six percent were killed.
It's a terrible disaster,
and I wouldn't want to minimize that at all, but again,
it means that these things are things we can prepare for
and are potentially very survivable
for the vast majority of us.
The potential loss of life in a Cascadia scenario,
even in some of the worst-case scenarios,
is only a very, very tiny fraction of the population.
Many of us will be very inconvenienced
by the damage that comes from the earthquake,
but I don't want people to think of it
as something that's not worth thinking too hard about.
So in the frame of talking about things
that we're thinking about then, one,
and it's one of many ways to prepare for earthquakes,
and we're going to hear a lot from the next two speakers
about other forms of preparation,
but one is, we've recognized,
through the USGS and its university partners
which includes us but also Oregon, Berkeley and Caltech,
that there's a capability,
a technological capability to warn people
before the shaking gets to them in many,
many cases for earthquakes and for tsunamis for that matter,
and that we can use that information
to help protect people and save lives.
So that's led to this something called Shake Alert,
earthquake early warning, and it takes advantage of the fact
that there are all of these seismic stations.
Ours are these pink ones up here at the PNSN,
but then California is loaded with them as well, of course,
and there's even a little bit of offshore instrumentation,
and use all of those stations to detect those P waves
and warn people before those damaging S waves get to them.
I'll show a little animation of that in a second.
So actually, Shake Alert is here in the sense
that we are already operating the system.
We're using it in a pilot mode now even in our region
and have some pilot infrastructure collaborators
who are using it to do real things
to protect infrastructure now and full-scale public alerting,
meaning via an alert that would come to your phone
through the WEA system, the, like, Amber alert-style system,
or an app just went live in California 2 weeks ago.
There's Governor Newsom announcing it,
and we're moving to public alerting in Washington
and probably in Oregon in October 2020
is the goal that the State Emergency Management Division
has set out and that we're full partners on with that,
so there's some of the examples, the direct emergency alerts
which are now potentially taking place.
That's the way everybody thinks of it potentially happening.
There's two issues with those direct emergency alerts.
One is that they only can show you a very simple message.
The technology is just a text message like this,
and the second is that because of just design of that system
and actually in part for some very good reasons,
they are built-in latencies
and delays that are hard to overcome.
It's no big deal for an Amber alert
to have it get to your phone 20
or 30 seconds after the alert, but for an earthquake,
that could be getting the alert after the earthquake hits you
instead of before the earthquake hits you,
so people are working hard on that problem
but also working on releasing these apps
that you instead download
which have at least the promise of reducing some of that latency
and giving us more information during and after,
crucially after the earthquake, like Shake Alert LA
and this other one up here called My Shake.
All right.
So how does earthquake early warning really work?
And the key thing is that,
it's not prediction of the earthquake.
It's detecting the earthquake as soon as it happens,
so there's the earthquake in the subsurface.
It starts.
It starts radiating waves.
Those first ones are the P waves.
The red, pink ones behind them are the S waves,
so the P waves start passing some of the seismic stations
which can then immediately transfer their information
over our telemetered data
or our Internet connections back to U-Dub
or the other centers within approximately, you know,
numbers like a couple of seconds.
The location of the earthquake and a rough estimate
of the initial magnitude is done,
and then it's determined whether an alert should be alert.
You beam the alert out, and then, yeah,
hopefully that doesn't happen,
but at least not quite like that,
but before the damaging waves get there,
so that's the fundamental principle behind it.
We've got lots of examples of ones that have been caught
during our whole development and testing phase.
This is just one where an earthquake took place
up there by Astoria,
and there was a first alert issued just a few seconds after,
less than 2 seconds following the P wave arrival
to the surface, and so that left 24 seconds
to warn people in the Portland region
of a potential earthquake.
The Monroe earthquake was close to Seattle.
That was a tougher one to do, a lot of advanced warning,
but our system generated a warning with about,
I think it's 8 1/2 seconds of potential advanced warning.
Not a lot of time, but enough time to mentally prepare
and do some of your activities like drop, cover and hold on,
and I'll show you something interesting about that
in just a second.
Here is another rupture simulation
for a magnitude nine earthquake by a different group
using some of the same kinds of simulations
that Erin just showed you at San Diego State.
It's again showing you a big magnitude nine earthquake,
and you can actually see the effects of the directivity
that you all are experts on now that Erin just showed us as well
as some of the concentration of seismic waves
in the softer rock offshore,
but if you look at the time scale,
I know it's tiny down there.
Two minutes have already passed since the earthquake started,
and by the time the waves get to Seattle,
it's going to be more on the order of 3 minutes-plus
down here on this time scale, and so what it suggests
is that for at least some of those scenarios,
there's a potential to detect it as soon as the waves come ashore
and then still have significantly longer amounts
of lead time in the Puget Sound region.
If it's closer and directly offshore,
then it's more like in the 30 to 40 seconds or 40
to 50 seconds kind of timeframe
but still significant amounts of time,
so different earthquakes give us different responses.
-Much more similar to the Mexican...
-I want to show you this video.
I was actually a graduate student doing...
-At 5:04 p.m., Latin American Studies One...
-...this kind of science at UC Santa Cruz.
-...was underway at UC Santa Cruz.
-I had been in grad school 3 weeks the moment
of the Loma Prieta earthquake
30 years ago, and here is a classroom.
I was probably just about two blocks away from this classroom.
Students just figured out the earthquake was happening.
They didn't drop, cover and hold on, did they?
Everybody got up.
Stuff is all falling from the ceiling.
Nobody should get in a doorway during an earthquake,
and nobody should try to exit the room.
It's the falling stuff that's going to hurt you
or injure you during an earthquake.
-With video cameras everywhere...
-And there are a couple more of these.
-...this is the most visible earthquake ever.
-This was the first earthquake where we had lots of security
cam footage and all of this kind of real-time or real data
showing what it was like during the earthquake.
Poor kid, I know.
And then, of course, we all know it
as the World Series earthquake, and the TV ended,
and that was, you know, what a lot of people heard.
Now, I was right on top of that earthquake,
and the power was out,
and we didn't even know how large an earthquake it was
until somebody came by in a car with the radio on, said,
"The Bay Bridge just collapsed," and that was the realization.
So I just showed you some really graphic examples,
you know, falling hazards...
Whoops, let me go back there.
...are very -- I went the wrong way.
It doesn't want to go back. There we go.
And injuries are linked to falls,
and the same goes for the Northridge 1994 earthquake,
so the cost is really high, and even just being able
to prevent a significant fraction of those,
there's opportunity to really save a lot.
So just as a contrast, this is Anchorage.
There was no earthquake early warning.
Watch from when these kids notice the earthquake
is starting.
They're all under the desk within less than 4 seconds
from when that earthquake started.
So this was our...
but of having that early warning actually puts your brain --
instead of preaching --
to do what you're actually supposed to do.
Automated control assistance, I'll skip over that.
I do want to kind of talk about this just a little bit.
Shake Alert earthquake early warning system
is an expensive thing, putting all this together.
There's an estimate that the capital investment
to make it is about $40 million total,
but it'll still cost us about 28 million
to operate it annually, so I think in our region,
it's good to put that in some units
that we can actually relate to because big numbers.
Twenty-eight million dollars sounds like
a lot of money, right?
But let's think about, you know,
something useful to the City of Seattle,
and so I like to define a unit as one Wilson.
Famously, he makes $35 million a year to play football now,
so the cost is about 0.8 Wilson units per year.
Not bad, right?
Okay, the last thing I'll talk about,
just if you'll bear with me for two slides,
is to say that the final frontier for us
is really moving offshore.
The locked-up fault zone is out there.
Our sensors are all on land. That's not good.
That's, like, sort, you know, the light is over here,
but I lost my keys over there, so how do I look for my keys?
So there are already some offshore scientific sensor
cables that exist both in Canada and in the US,
and there a few of those seismometers
that are starting to be on the seafloor
that can feed data back,
but we need a lot more of that kind of information,
and there's been a lot of work go into trying to determine
what sort of earthquake early warning we could do,
and we're looking right now
at adding a lot of seismic detection systems
and other things to this region off Oregon
where the cable already exists.
We'd love to see that go a lot further.
So just to sum up, they're a real concern, right?
But we prepare not to spare.
I think that's one of my key messages,
and early warning is on the cusp of reality here,
and we want to integrate it,
and it's an and, not an or, right?
An and, not an or, with regard to other resilience efforts.
This doesn't replace preparedness.
Thanks very much.
-That was really good. Thank you very much.
[ Applause ]
So, again, we're going to do questions at the end,
and Erin is going to queue up our next talk.
So, our next speaker is John Hooper,
and John is a senior principal and director
of earthquake engineering at Magnusson Klemencic Associates
here in Seattle.
We've had a long working relationship with John,
probably 25 years now, and he takes our stuff
and really puts it into action and puts it to use
and puts it into designs of buildings here
that we live in and work in every day,
and so his work is extremely important and very valuable,
and so John is going to talk to us about the engineering
and the built environment here in the Pacific Northwest.
-Thank you, appreciate it.
A pleasure to be here, thank you for that,
and built environment relative to earthquakes
because that's what we're talking about here tonight,
and actually we go back over 30 years,
back to 1988 when I first met Brian Atwater
when he described to me the subduction zone earthquake,
for which I didn't believe him for about a year or two.
He convinced me at the very end.
What I want to talk to you, though,
is about the history of code development,
kind of give you a sense of our building stock
here in the Puget Sound area and what you can expect from it,
not just new, brand-new towers
that have been designed in the last 5 to 10 years,
but the stuff that's been around here for over 100 years,
and we've been trying to deal
with this phenomena of earthquake
for about this 100-year time frame.
What we're trying to do is provide guidance
for engineers like me and others in the Puget Sound area
to design procedures that are simple,
economical and reliable
to protect life safety, to protect us as individuals.
Property is on there,
but property isn't our major focus at this time.
It hasn't been easy to make these changes
because we have to wait, generally speaking,
for the most part of this 100 years for earthquakes
to tell us what works and what doesn't,
so you have to learn from that
because Mother Nature is the best teacher of all,
and it's not even close to perfect yet.
We heard about this new information
about the crustal events that I just heard
for the first time tonight.
The magnitude is a lot higher.
I've heard about it before, but the magnitude is higher,
and the return period is shorter.
That changes the dynamic of what we should do in building design.
So I'm going to take a kind of a walk
through earthquake engineering history
and what we've learned, and by and large,
the majority of what we learned is from California.
Don't despair. California is a good state.
We like them, they're good,
but we work hand-in-hand with the state of California,
and so what they learned in California --
-The mic. -Oh, yeah, sorry --
we use here in the Puget Sound area,
so these lessons are very germane to what we do.
We all heard about the 1906 San Francisco earthquake.
Interestingly enough, nothing became of it
in the design of buildings in San Francisco
following that event.
A missed opportunity: They may have been working on it,
but nothing really happened until 1927.
That was the first building code that was formulated
that governed design of buildings
mainly in the Western United States,
and within that document,
they did have earthquake information and requirements,
but in what is called a nonmandatory appendix,
meaning you could do it or not.
It depended on you the engineer or the jurisdiction
that was adopting this building code for use of designing
and constructing buildings, but if you did do it,
and you did know that earthquakes --
You see the word in there.
The earthquake shaking is moot,
meaning if it's happened, you should design for it,
and they gave some information to the engineering colleagues
back in the time of what to do,
but again, it wasn't uniformly done
throughout the Western United States back in '27.
The next big event that really changed a lot
is the 1933 Long Beach earthquake.
It made a lot of changes in California
that permeated its way up here very quickly.
They made a bunch of legal changes,
one called the Field Act in California,
very famous for them.
It banned unreinforced masonry buildings.
Those unreinforced masonry buildings
still exist in the Puget Sound area.
You see a lot of them in small towns around us,
a lot in Pioneer Square.
We adopted that same ban not in 1933,
but by the 1940s we said,
"You can't build out of this material
because you see response of buildings like that."
They also did something called a Riley Act,
which basically said, "We need a design for earthquakes
to a certain amount of force, how much the earthquake
is going to try to push your building sideways
due to the ground shaking underneath it,"
and so that was developed back in 1933.
We still use that same number today
throughout the United States.
Interesting that we use the same minimum force.
It can't be anything less than this in any building design
anywhere in high seismic,
and as you know now, we are high seismic.
The next seminal event was the 1971 San Fernando earthquake,
so remember you saw other --
Pointing out to the events that we had here in the
Puget Sound area, the '49 and the '65,
we were very clearly understanding
that we had earthquakes happening here.
We knew they were probably different can California
because we can't see something called the San Andreas Fault,
which you can actually see and walk over,
so that we were doing
the right things consistent with California.
So when this happened, we knew that this kind of thing
would be expected up here in the Puget Sound area as well.
What did we learn?
Pretty simple: Don't build on a fault.
Two things happened.
They created the Alquist-Priolo Act in California,
which mandated that you could not build on the fault,
and the building code itself about,
oh, 25 years later did the same thing.
If you have a fault, and you know it --
Some of these faults are hidden faults,
so you don't necessarily know where they're at --
You can't build there.
Walls must be tied to the roofs and the floors.
Boy, that sounds like a good idea.
Why would you stack a bunch of walls
and put a bit of roof on it
so they could just fall right off?
It makes no sense.
We were doing that back in the '60s and '50s
and beforehand.
Yeah, we learned the lesson the hard way.
There's a term I want to talk to you about called
non-ductile concrete.
This is concrete buildings that don't have sufficient amount
of reinforcing steel within them
and the right orientation in that reinforcing steel
is from this earthquake that we really started
pushing the fact that concrete itself is not a bad material.
It's its interaction with the reinforcing steel
that is inside of it
and how it all connects together wasn't being done very well,
and so if you think about that, by the mid-1970s
we think we kind of solve the problem.
We never really solve it. We think we do.
Anything built before then that's concrete,
maybe not a good thing, maybe not a good thing.
And finally, some structures are more important than others.
What that means is, we understood that
if you're a hospital, your design objective
for seismic performance should be higher
because that's where people go when they're hurt,
versus just a residence.
You could argue that shouldn't be the case,
but we separated performance
between what we call essential facilities
and ordinary occupancies like we are in here today.
1985, Mexico City, big buildings fell down,
15 to 20-story buildings fell down,
like this, the Pino Suarez.
This is the detail for the really engineering nerdy guys
and gals in the audience.
Steel columns collapsed because they weren't strong enough,
and so we fixed that in the building code
so that we don't have that problem anymore.
Again, Mother Nature is really describing what we should do,
and she tells it to us very well,
and buildings that are next to each other,
that could be a problem. They pound.
They hit, and they cause damage and potentially collapse
where they hit together, and we changed our requirements
because of this earthquake how far apart
or how close two buildings can be built to each other.
Before that time, we didn't have rules for that,
so you think about buildings around here
that are really close together.
As you walk by them, think about that or not.
It's your choice.
I think about it way too much, obviously.
In 1994, Northridge earthquake,
it showed us the best system that we thought we knew about
was what we call steel frames.
They cracked.
Steel can crack.
This is about a --
Oh, this pointer is not working anymore, it doesn't look like.
That flange you see right here,
that's 3 inches thick of solid steel cracked wide-open,
and that happened in numerous buildings in this earthquake,
so we had to develop a whole new way to doing steel buildings,
and so anything built before 1994
has the potential for looking like that.
This is a tougher slide to see.
These are what we call tilt-up buildings.
They are basically concrete wall buildings
that they actually build the concrete on the ground,
and they tilt them up, and they make warehouses out of them.
Think about the Kent Valley
and all those warehouses like that.
Before 1994, the separation between those walls and roofs,
they separated way too much,
and we lost 200 of them in that earthquake,
so we improved that connection to make them stronger
than we had previously to help mitigate that from happening.
So that's kind of the history lesson through time
that I just picked the top four or five events.
I want to really emphasize what we've already heard tonight
and what benefits we've had,
this interaction with the USGS over this time frame.
You've seen this slide before.
I want to say what this means to the engineering
and the built environment.
Well, we recognized the Cascadia Subduction Zone
in the late 1980s.
Again, Brian Atwater came and the USGS colleagues
to the Structural Engineers Association of Washington, says,
"I think we have a problem,"
and we sat down for several years
and tried to figure out how big of a problem it was,
and by about 1992, we changed our building codes
to account for this shaking,
a collaboration that goes back to that time frame.
Recognition of the Seattle Fault,
we knew that we had shallow coastal faults,
but we didn't really know the size
and the recurrence, et cetera.
We now know it's even worse,
thanks to the research that's going on at USGS.
Thank you, Brian.
I don't want to talk to him anymore.
And so again, that will change what we do in the future.
It'll take some time.
It'll take 5 or 8 years.
It doesn't happen overnight,
but it's good to have this collaboration
to help solve these problems together.
And then finally, the recognition
of the Seattle Basin.
You saw the examples that Erin showed about those simulations.
We knew about them probably a little bit before this.
We started incorporating them into our tall building designs
about 2010, not exactly the way it's being done now,
but we recognize it and we try to think about it
and try to make sure our tall buildings
accounted for this in some degree,
and I'll show you a little video here
at the end of the session tonight.
I do want to talk about the fact that,
when we design buildings --
I'm not sure you're aware of this --
that we have to follow building codes and standards.
The building code is adopted by the state of Washington,
for instance. It becomes law.
It's something we engineers have to follow.
Within that, though, the actual criteria for earthquakes
comes in what -- the standard is called,
this screen, the Seahawk book.
It's called the Seahawk-colored book, ASCE7-16.
That tells us how to design for earthquakes in there,
and what it basically does,
it talks about how strong the building needs to be.
Remember, that 3 percent is a minimum.
That still again is in this document, and how stiff it is,
I mean, how much an earthquake can cause a building to sway.
We want to make sure it doesn't sway too much.
It also tells about how to connect the pieces together,
how to connect the vertical columns and horizontal beams
so that they will work together and perform in a robust system
that can absorb the earthquake energy,
and finally, it provides the requirements
from nonstructural components.
You saw in the videos that the stuff above you
in every room I go into,
I never ever sit underneath a chandelier.
Why?
You saw these videos, but we do have requirements for that
as well to try to minimize, it doesn't do it perfectly,
that damage that's caused from nonstructural components
falling all around us.
Within that, though,
I want to describe our objective performance.
What are we looking at when these different
earthquakes occur?
So I want to describe to you our performance
objectives and performance level.
I'll start with a cartoon series.
We're in this building here.
It's operational, and this is what we expect.
Ninety-nine point ninety-nine percent of the time,
a building performs like this.
The Earth starts to shake.
Things can go wrong.
Things can happen.
The next performance level we think about as engineers
is called immediate occupancy.
It's a performance level such that
we're still sitting in here.
There may be some ceiling tiles falling down.
We may have lost the lights for a little bit,
but we can get back in and use that facility quite handily.
What we target, though,
is something we call life safety.
After a major event, we want people not to die
and not to be seriously injured if we can help it,
but in doing so, damage occurs to the structure,
not just the nonstructural components
you saw in those videos but to the structural elements
that are designed to support the building and support the energy.
And finally, if the very rare event comes,
the very, very rare event,
we don't want the building to collapse,
or we want a very low likelihood of collapse.
That's when the major deaths occur from the shaking hazards
when that last little graphic occurs.
Let's look at this with real pictures from real earthquakes.
What does this look like?
This is from the 1999 Jiji earthquake in Taiwan.
These buildings are being occupied
immediately after the event,
being used and occupied and people living there.
Right next door to these buildings are buildings
that absolutely collapsed,
so you can see in one slide the immediate occupancy
versus collapse in the same slide.
That's a graphical representation
of a picture of real buildings.
Here are visual of buildings at a life-safe level.
The structural elements that are designed, again,
to support the building and absorb that energy,
those elements do get damaged.
This building is safe.
Nobody dies in this building or even gets injured,
but then the repair costs could be large
and may not be economical to repair at all.
You go a couple blocks away.
You see buildings like this that are teetering on the brink.
They didn't collapse.
This is collapse prevention, but you can see,
they needed to brace this building here in the corner
to make sure that it didn't fall over in an after shock,
so that's the cartoon version.
Real picture is hopefully providing
an image of what we do,
of what the performance levels look like.
What are we suggesting in the code that we delivering,
or we're attempting to deliver?
I'm going to present to you what we call our
seismic performance matrix.
It sounds like an engineering term, right?
It's just a table of information and definitions.
On the one side, we talk about the ground-motion levels.
The amount of shaking matters.
We talk about the frequent shaking at the top.
That's the earthquake that occurs
about every 25 to 50 years.
That's the Nisqually type of earthquake for us here.
That's that one.
The next one is the design earthquake.
That's the earthquake we design for in the building code itself.
That's the one we target as our performance,
and the last one --
And that occurs about every 300 to 600 years
depending on what part of the country you're in.
For us, it's about 600 years,
and then last one is a maximum considered earthquake.
We define it as that because that's the maximum one
we want to consider
because Mother Nature knows no bounds,
so we want to kind of do something that seems reasonable.
For us, that's about a 2,000-year return period event,
not in our lifetimes.
What kind of performance?
We take those same performance levels
I just showed you, operational, immediate occupancy,
life safety and cost prevention,
and we marry the two together and describe with a line
what we are trying to achieve.
So for a standard building, a standard brand-new building,
and you could think about all those brand-new buildings
in downtown
Seattle that have been built in the last 10 years,
that given that design earthquake,
that dot in the middle says that we want to be life-safe.
That event that occurs about every 600 years, it's life-safe.
Given that very rare event,
that 2,000-year event here in Seattle,
we don't want the building to collapse,
or it has a very low likelihood of collapse.
And then I also have in this slide
what we call a basic retrofit objective.
We do the same things when we fix up existing buildings.
I'm not sure you're aware that you're in a building
that's been retrofitted.
Our company had the pleasure of retrofitting this building
to that performance level, so we should be okay.
I'm not guaranteeing a darn thing.
As I mentioned before, though, we look at essential facilities
are these buildings,
occupancies differently because we as a society need them
to a higher level like hospitals,
EOCs, police stations.
We design them to a higher level of performance.
Given that design earthquake,
we shoot for immediate occupancy,
and for that very rare event,
we shoot for life safety for their performance.
So I just want to emphasize
that we don't earthquake-proof anything.
Damage will occur.
We try to control the damage by the way we design our buildings,
so I want to go through and kind of uncover.
If you look at a building, what is inside the building
that guys like John Hooper cares
about that helps protect the lives of people?
I want to show you the systems that are typically used
that support a building during earthquakes.
I'm going to go through a handful of them.
This is what we call a steel moment frame.
This is the one that performed badly in 1994.
Luckily, this was built after 1994.
This was a building in Seattle that our firm designed,
but those horizontal beams, those vertical columns,
those combinations are what is designed
to absorb the energy from the earthquake
and keep the building from coming down.
You can take a steel building and put these braces in them,
these little crossbraces. You see them everywhere along here.
Again, these are all Seattle buildings,
and that, those braces, those X braces absorb that energy,
and that's another one of our systems that we use quite a bit.
Just so you know, there's over 80 systems we can choose from.
I'm not going to show you all 80. We'll be here all night.
I'm going to show you my top five.
This is a concrete moment frame.
This one happens to be in Belleview.
It's similar to steel, but it's made out of concrete
and a whole bunch of really, really important
reinforcing steel within the concrete to do the work
and protect the building from swaying back and forth too much.
Some may recognize this building in Belleview.
This is exterior concrete sheer walls.
Those are all thick walls with a lot of reinforcing steel,
and that is designed to do the work to protect the building.
Over the last 15 years,
nearly every tall building you see in downtown
Seattle or Belleview is made out of this or supported by this.
If you unpeel the exterior of the building,
concrete core walls.
They are very robust, the combination of the beams.
The pointer doesn't work anymore.
Combination of these beams and these walls together
are what protects the building,
and there's a lot of reinforcing steel.
If you ever had a chance to walk by one of those sites,
you saw something.
You probably couldn't even see through the reinforcing steel,
it was so dense.
And finally, where most of us live,
in houses, hopefully, what's there is just a plywood.
This house would be my beach cap,
and I made sure I had a lot of plywood.
I wanted to make this one as robust as --
But that's the type of material that's used
in probably 90 percent of the buildings
that get built anywhere in the United States
is built like this, and the plywood you see there
and all the walls is what is there to resist that.
And I also want to re-emphasize nonstructural performance.
It accounts for over 70 percent of the earthquake losses.
Might even be closer to 80 percent,
but critical systems are designed to a higher standard,
like the sprinkler systems and egress stairs
so that the fire can't burn it down.
We learned that in 1906,
and also that you can get out of the building safely.
We designed it for a higher standard.
I want to show you, though, the technology
has changed dramatically for us. Here is a tall building,
the tallest building in San Francisco.
This approach we use to simulate earthquakes,
we take the earthquakes from Erin,
and then we simulate our system,
and then we see, and we -- This is overexaggerated, people.
This is moving a lot more than it should.
We look and make sure that the building is robust enough
to take this level of shaking,
and this happens to be a magnitude eight
on the San Andreas fault.
In Seattle, we use a magnitude nine on the Cascadia
to make sure that the components that are supposed to resist
that earthquake energy can do so, so that's the technology.
That has come a long ways for us.
Again, exaggerations, people, exaggerations.
Exaggerations.
I'd like to close with this, the future efforts.
I think we're a long ways to doing the life-safety
pretty well. I hope we are.
I hope Mother Nature doesn't surprise us too much next time.
What are we doing to help improve resiliency
in earthquake engineering and design?
We want to look beyond life safety and collapse prevention.
That's necessary but not sufficient.
What we're trying to do is estimate,
given our current designs for life safety
and collapse prevention,
how long it takes for the building
to get repaired and back to use,
what we call functional recovery,
after, let's say, a 500-year event.
Once we understand how long that is,
and we don't like the answer,
we can start to provide new ideas,
design and construction strategies to reduce that
so that we can get back into our buildings
and instead of 2 months, 5 days or something like that,
so we're looking at that as a whole new paradigm shift
because I think we as a society want
and should be doing more.
With that, I'll close.
-That was wonderful.
Thank you very much.
[ Applause ]
That was great.
So our final speaker tonight is Barb Graff,
and I first met Barb back in I think 2000
when she worked as the emergency management director
for the City of Belleview.
She is now the director of the Seattle Office
of Emergency Management, and she's going to talk to us
tonight about emergency preparedness.
-This is great news.
I'm enjoying here tonight because ordinarily,
I am the most depressing speaker of the night.
Erin had be 5 minutes in,
and if you stayed awake for Harold,
everything I have to say is good news compared
to everything that they shared with you,
so this is fabulous. So just FYI,
I want you to be aware of the fact that emergency managers
all around the world and very much so here in Seattle
are utterly best friends with our scientists,
with Joan and Brian and Art and Erin
and Harold and Steve and Brian and everyone else.
We believe what they say,
and I'd like to share a little bit with you
about what it is that we've been doing
with their information as a result.
First, we're trying to humanize and personalize
that risk information that they spent a lot of time
and a lot of really good study on.
We created a hazard map that we put on our website
so you can click on your home address
or your kids' school or your doctor's office
or your mother's house to find out,
is it in a flood plane?
Is it built on soil that could potentially liquefy?
Is it a building that, as far as we know,
is an unreinforced masonry building?
The more you know and personalize the risk,
the more you're actually likely to do something about that.
I'm going to talk real briefly about the kinds of things
that the City of Seattle as a representative city
has done with this risk information.
One, we plan our hearts one.
In the City of Seattle alone,
go to our webpage, seattle.gov/emergency.
You'll find a comprehensive emergency management
plan and emergency operations plan,
a recovery framework, all hazards mitigation plan.
You'll find a continuity of plans,
continuity of the government plans,
continuity of operations plans, incident-specific plans
including an earthquake response plan.
You'll find all kinds of things that have prestaged
what our intentions are in any kind of an incident.
Additionally, we have partnered
with an interesting start-up company called One Concern
to model at a much more granular block level,
what are the kinds of damage we might expect to see?
How many people of different ethnicities and languages
and income levels live in each one of those blocks
that we need to plan better for?
And we also had just relatively recently finished up
a seismic study of the entire water supply system
for the City of Seattle.
Next, we train, so there's 250 people
from our 30 city departments who get trained
on a regular basis on what their role
is in an activated emergency operations center
in order to provide response and relief to our community
in any kind of a hazard but especially an earthquake.
We spend 85 percent of our time focused on earthquakes
because you focus on that, and you're kind of covering
almost everything else on your bad-day list.
We participate in exercises.
We don't wait for the earthquake.
Like you heard earlier, it's like John said.
It's tough to wait to see if your best assumptions
were good assumptions waiting for the earthquake to happen,
so we actually design exercises to stress
the plans that we built and trained on to find out,
how can we improve them?
We also send people around the country
and around the world to help in different disaster situations
because they come back better inspired with good ideas
to improve our plans.
There's a number of projects that we have spent
a lot of funding on here in the Northwest,
and so I want you to be aware of that.
Some of those are, we have finally torn down the viaduct
instead of waiting for the earthquake
and two sneezes to take it down for us.
Yes, we got it done.
Thank you very much.
The tunnel has opened up.
Yay. We're making our way along.
We have completely redone the Elliot Bay Sea Wall.
We like separation between water and land.
We rebuilt from scratch in a new location Seattle City Hall.
These are some of the essential buildings
that John was referring to
because of the services they need to provide.
New City Hall, the Justice Center,
the Fire Department and Water Department
training center and the Fire Alarm Center
so we can still take 911 calls and dispatch appropriately.
Additionally, we used to have located
in the Seattle Municipal Tower our main data center
with all of our critical operations on floor 22,
and we were finally embarrassed enough to face that.
We've now relocated and made two redundant centers
outside of any kind of high rise or area of danger.
Additionally, and I give credit to this to Mayor Nickels who,
when he visited Kobe, Japan in 1995 after their earthquake,
he came back with fire in his belly
and recommended to the citizens of Seattle,
"Let's do more for public safety,
especially in the earthquake arena."
We now seismically retrofit all of our fire stations
so that the units and the firefighters
can actually get out and do some good.
We hardened the water hydrants
so they can draw water more reliably.
We built the city's emergency operations center
that we now occupy.
We cached stores of emergency congregate care supply materials
so that we can take care of at least 4,000 people
right off the bat in different areas of the town
and many other things in order to get ourselves
much better prepared.
Additionally, our community centers,
our Parks and Recreation centers
are those facilities we would use for mass care
and congregate sheltering,
and we've taken the time, trouble and expenses
to make sure that they have been seismically mitigated
so we can use them for that purpose.
For the top tier,
the highest-capacity community centers,
we've also installed permanent generators,
and we have a fleet of generators
that can be rolled around to other critical facilities
depending on what their function is.
One of the top dangers right after the shaking
of an earthquake is the exposure of fire,
and given the fact that your fire-suppression systems
could easily be damaged, et cetera,
we went ahead and installed automatic gas shutoff
valves at 35 of the city's most critical facilities
so that a certain calibrated level,
and this isn't just a heavy truck passing by,
but natural gas will automatically be shut off
so that we're protecting from a secondary danger
that hasn't yet even happened.
John touched a little on unreinforced masonry.
I could talk about this one for 4 hours,
and you'll be glad to know that I'm not going to,
but the good news is that at least for the last 7 years,
the city has been trying to figure out
how to be the first city outside the State of California
to mandate seismic retrofit of the 1,145 buildings
that make up our unreinforced masonry inventory,
and we're going to get there.
This afternoon, I was just in another meeting
in the mayor's office about,
how do weave together the financial incentives
that help not displace the low-income,
the minority populations
and the historically significant buildings
that we don't want to lose in our next earthquake?
This is not an easy thing to do.
This is about a $1.2 billion proposition,
and unlike the other billions of dollars of investments
I showed you that the city made with tax dollars,
that's $1.2 billion on private property owners,
so we're trying to be sensitive about the way we do this.
We tried it in the early 1970s,
and then following the 1965 earthquake.
Earthquakes are a great motivation,
but it doesn't last long, and so we passed an ordinance
and within 4 years had repealed it
because we had not been thoughtful enough
about how to make sure we could put a retrofit ordinance
in that would address this,
but 33,000 people at any given time any day are living,
sleeping, working or dropping their kids off at a school
that is an unreinforced masonry building,
so we've been in a very close-knit tie
with Portland for a number of years
trying to shame each other into seeing
who's going to be first at this. I guarantee you,
Seattle is going to be first to get around to this one.
Town Hall, John stole the thunder.
It's seismically retrofit, so give yourselves a hand.
You're in a safe building, no hurry to get out.
Bars open as soon as I'm finished here,
but in addition to that, in addition to Town Hall itself,
we have since 1997 been teaching classes
to people who live in the community
whose single-family wood structures are not adequately
secured to their foundation
because they were built to a previous, older building code,
and so we started a program called Project Impact
way back in the mid-to-late '90s where we teach people,
"Here is how you can do the work for yourself
if you're willing to do that."
We have two community groups
who actually loan you the tools to do it
if you don't want to buy the tools.
We teach contractors, and since 1997,
we continue to teach those classes into 2019,
and they continue to be standing-room only,
so I'm so impressed about the investment people
living here in the community themselves
are making in disaster preparedness.
But in reality, with all that investment that we've made,
it's still going to be a horrible day,
and so the most important thing to remember is,
this is where I do get depressing,
as all my remaining colleagues.
What you need to remember is, the just-in-time delivery,
including just-in-time delivery of your dinner,
things just aren't going to be normal
for us for quite some time.
We have hundreds of bridges in our city alone
let alone the thousands that connect us
to the rest of the world.
With so many different important enterprises including hospitals
that count on just-in-time delivery of services,
this is going to be urban camping
for a certain amount of time,
and so we're trying to encourage people
to personalize this risk can say,
"You need to do something about this at the household level
the way your city has been doing it
with public buildings as well."
Toward that, we teach more
than 10,000 people annually in person,
not to mention all the people we try to reach
with TV programming, with our websites.
We have our volunteers here tonight.
Say hi to Cindy and Ann and others on your way out.
They're doing an absolutely fabulous job.
We hire people who are culturally competent and fluent
in a language other than English to teach the classes
on our behalf in order to get to --
especially immigrant and refugee communities
who don't necessarily trust the government.
However, you don't have to be an immigrant or refugee
to not trust your government these days.
I need to change that as I do that.
We have been encouraging people to sign up for a program
that we have called Alert Seattle.
You won't need this to find out about the earthquake.
As Harold mentioned, earthquake early warning is on its way,
but when we can send you information
about specific areas of damage,
a utility disruption, a traffic disruption,
a law enforcement activity going on in the area,
sign up at alert.seattle.gov
so we can push that information to you.
And then finally, and we've got these brochures
over on the table, it is all about preparedness,
and so a lot of people think about
gathering their supplies, right?
A lot of people think about putting a good plan together.
Who's going to contact the kids and out-of-area phone contact?
Great, but I'll tell you, I'm absolutely inspired
by a disaster sociologist by the name of Daniel Aldrich
who has studied these disasters for decades
and has proven what gets us all through a disaster
is a sense of connection,
and so what you need to do in addition
to the fabulous supply kit you've got
and the wonderful plans that you've laid out,
you actually do need to get to know your neighbors,
and you do need to talk about this at work,
and you do need to ask your kids' school
if they've done a drill recently.
More people get themselves through horrible disasters,
especially no-notice ones, by counting on one another.
It works. There's some fabulous literature
out there that you can read about,
and all of his books are listed on our website,
but it's what we need to do.
The last thing I'll say so that we can get onto questions
and again, this is amplified over
with our community volunteers on the side of the room.
Through researching disasters for a long time,
we realized especially in earthquake country,
people naturally are very altruistic
within the early hours and days of an event like an earthquake,
and so we thought, what can we do to help
make that connection happen?
And so we worked with a lot of community members
throughout the entire city to say,
"Where close to you live or go to work
or wherever you spend your time,
you tell us where a natural meeting place
is so that if you needed to help one another out, you could."
Anybody want to guess how many firefighters
we have on duty tonight?
Two hundred? Very good, about 210,
and all of them are absolutely spectacular,
but they team up, and so there's only about 35 apparatuses
that they all ride on.
That's the same number we're going to have
on the day of the earthquake.
What you can count on, though,
is another seven and 130,000 people
who live here who have taken CPR training,
who have taken classes like this,
who have organized themselves into groups
willing to help one another out.
This works.
Community hubs are simply locations
where we encourage people who need help,
and people who can help will get themselves together.
I'm going to go ahead and abbreviate myself
so we can get to questions because I bet you guys
have a lot of things you want to ask us about,
so, fellow presenters, come on back up again.
-I was curious about the intervention of --
I've been a little bit obsessed with gas, the gas shutoff,
and particularly the opportunity to have that
in homes feels like -- And I'm curious,
what other kinds of interventions like that,
if you could sort of have your wish granted,
that you would be able to get people to do, would you want?
-Learn about the rest of your utilities,
so automatic gas shutoff valves, great idea.
If you're doing this in your home,
be aware of the fact a professional needs
to be able to restore the gas after the shaking itself,
but learn where you could turn off your water
so it doesn't become contaminated with other damage
that's been done in the system.
You got a lot of water in your water tank.
Some of you have a lot of water in your water tank,
and you get to know your neighbors in case you don't,
but think about what else you can do to kind of shield off,
you know, your home, and then share.
It's stone soup, and actually, a lot of people do this
naturally during power outages. I do.
I always take the dog out for a walk out in the neighborhood
and, you know, start talking with people
about what it was they experienced.
Last mile is an important point that you brought up also.
Seattle is participating
in an eight-county-wide planning effort right now,
regional catastrophic planning,
in order to identify with a lot of good information
from transportation managers, geologists and others,
where are the most likely places,
once we can get supplies into the area,
that we could put points of distribution
so that I can, within the course of the grant, within 2 years,
be able to give you with a certain level of confidence,
exactly where am I going to drop off food, water,
sheltering materials, et cetera?
-Yes, sir. -My question for Dr. Wirth.
You showed simulations of the M9 earthquake,
and it happened in 10 seconds.
Can you give me some idea of what the time scale
was for the arrival of the shaking and the duration?
-Yeah, so the actual rupture does take some time.
It's more on the order of a minute or two,
I would say, or a few minutes,
actually, and then the duration of shaking,
so we often like to compare this to Nisqually,
so I think Nisqually was about 20 seconds or so strong shaking.
Someone on the stage can correct me if I'm wrong,
for the Seattle area,
and then for a magnitude nine earthquake, we would expect
that it would be more like 100 seconds of strong shaking,
so about four, five times longer for a magnitude nine earthquake
for the duration of shaking in the Seattle region, so, yeah.
It's maybe a little bit longer
than you thought based on the simulation.
-Hi, there.
Thank you all for coming tonight.
-Thank you. -Thank you.
-My question for John Hooper, you spend most of your time
for residential and commercial structures.
Is there any history or performance data
on liquid storage structures like tanks,
water petroleum, that sort of thing?
-Yeah, as part of that ASCE-7 standard,
there's a whole chapter just dealing with
what we call nonbuilding structures
including water tanks, petroleum tanks,
all of those tanks, and they are,
if they're in earthquake country,
are designed for seismic performance
equivalent to what we do for buildings
and sometimes higher because of the contents.
-Yeah, how do they do?
-Well, we had a real-life example down in Chile, 2010,
and the newly designed water tanks and petroleum tanks
all did actually very well with a magnitude 8.8 event,
so they designed very similarly
to what we do here in the United States,
and that was a great test of Mother Nature, again,
that what we do as engineers
seems to work well for big storage tanks.
-Can you speak to the small
mom-and-pop residential rainwater tanks?
Thousand, 2,000.
-That is exempt from our standards,
so I really can't talk about that one.
I hope they work fine.
-Hi, this question is also for John Hooper.
It's kind of, I guess,
more leaning towards the structural end,
and the simulated model that you showed of the tower,
the tall office tower in San Francisco,
to what extent is glass curtain wall
covered in sort of the structural design of buildings?
-That's a great question:
Will we be raining glass down on the street?
-Yeah. -Again, looking at our standard
that we use to design buildings to, given the design earthquake,
we design the glass not to fall off,
so that's a pretty big event.
So we have a chapter just for that which is good,
and even given the maximum considered earthquake,
the one that occurs about every 2,000 years,
and all the new buildings we've been designing around town,
the engineering community,
even the cladding itself is going to stay on.
It's designed to stay on, so we've really upped our game,
if you will, in the last, oh, probably 15 to 20 years
thinking about the hazard to the public around a building
instead of trying to mitigate that situation.
-So I guess for, you know, downtown Seattle
where there's all of these tall glass skyscrapers
that are being built,
the assumption is that the majority of them...
-The majority of the new ones. -...are built to the new codes.
-Oh, yeah. The new ones, yes.
I can't talk about 40 years ago. That's a different animal.
-Sure. All right.
-So we're going to alternate, so, please.
-Three questions, but all fairly quick ones.
Most of us over here in Seattle that thought
that we were protected from the effects of the tsunami
by having all of that land between us and the ocean,
looking at the simulation, it looked like
it roared right into Puget Sound right into Lake Washington,
wiped out everything in a houseboat on Lake Union.
Just wanted to find out: Is that a correct perception
that even Lake Washington
is going to get hit by this tsunami?
-So let me preface this first.
So I mentioned that there's a wide range of possible
ground-shaking scenarios when there's an M9 earthquake.
There's also a wide range of tsunami scenarios,
but we do expect, of course,
the largest and most damaging tsunami
is going to be along the coast.
We will have a tsunami
that travels down the strait of Juan de Fuca
and into the Puget Sound region, but that will take some time,
maybe an hour and a half to 2 hours after the earthquake,
so there should be plenty of warning for Puget Sound area
residents that are right on the water to get off the water,
and we don't expect the tsunami to be nearly as high by the time
it gets that far inland,
so I've seen some simulations of a magnitude-9 earthquake
that show maybe a meter or so tsunami in the Puget
Sound region, but again, it takes about an hour
and a half to 2 hours to get that far inland.
I don't know if anyone else wants to comment on that.
-Well, I was just -- -Go ahead, Brian.
-I was just going to add one comment.
We just had a student finish up her PhD looking at that,
and she found a couple of spots in Puget Sound
where there is geological evidence supporting
a tsunami running ashore that appears to be correlated
with some of the past subduction zone earthquakes,
and in those particular areas,
the model predicts up to a couple of meters of run-up,
so in isolated areas,
it could be quite a bit more than a meter.
Yeah. -Okay.
I was wrong.
That was going to be my quickest question,
so maybe I better just do one other
because I don't want to steal everybody else's thunder.
A lot of the preparation seems to be dependent upon,
or the reaction seems to be dependent on cellular telephony.
How confident are we that our cellular networks
are going to be there functioning
and having access to power after things happen?
-Not. -Damn it.
It was a quick answer, though.
-So for instance, we have -- We've done a city-wide
duty-to-report policy discussion,
and the members of my staff know you shouldn't expect a call.
You shouldn't expect a page.
You shouldn't expect anything over the radio.
If you felt it, that was your call to come into work.
-Yep. -Very good.
-So this is not directly related to earthquakes,
but I'm curious about all of our volcanoes
along the Cascades.
Will they be affected and become activated
by any of these larger earthquakes?
-It's -- Yeah, it's an obvious potential question to say,
"Well, if there's so much shaking,
could it not shake something loose in a volcano?"
And there are examples from the past,
from the last century of history,
of volcanic eruptions that seemed timed
sort of suspiciously closely with very large earthquakes,
including the biggest earthquake we know about, 1960, Chile,
but when people really try to look
at those sort of systematically and look for statistics of it,
it turns out that if there's any correlation,
it's very, very weak.
I think the most you could say is that there's the potential.
You could sort of make the hypothesis that a volcano
that is balanced right on the edge of erupting anyway
could be triggered by the ground motion,
by the strong shaking that comes through from the earthquake.
Other than that, we don't see evidence on a global scale
that that's a significantly frequent or likely event,
good news for us at least. -Certainly.
-Positive for us. -Yes, exactly.
-My question is directed at Barbara Graff,
and I'm not certain what your proper title is,
El Jefe or Madam OEM or --
-Barb. -Barb, Barb, thank you.
-That's awesome.
-There was a mention of a 2016 Cascadia Rising report.
I may be the only person that ever read it,
and it was refreshingly honest and horrifying at the same time,
and it mentioned the pulling of resources into a disaster area
and said it wouldn't work.
You had to shift to a push system
whereas the local area so --
on its lips that the government, the national level,
has to come in without us asking them.
Can you talk a little bit about that for me?
-Yeah, I'd be happy to. -Thank you.
-Cascadia Rising one was the June 2016 functional exercise
that involved four states, British Columbia,
all four levels of government, public or private sector,
20,000 people participating all at the same time,
and it was meant to simulate what does happen
in a catastrophic earthquake like Cascadia
where all of Western Washington is absolutely decimated
but where along the I-5 corridor,
you've got the majority of the Washington State population
shouldn't be expecting a whole lot of help or resources
because of what's happened out on the coast.
Eastern Washington, Eastern Oregon,
little bit better off, we did a lot of really,
really in-depth planning with the National Guard to say,
"What size planes need to make it to Fairchild?
What size aircraft then need to make it to Moses Lake?
What size aircraft then make it in?"
We planned with the Navy, with the Coast Guard,
with all kinds of different people,
and the assumption has changed over the years.
It used to be, you know, we have an earthquake.
My mayor calls the governor and says,
"This was horrible. Can you help?"
The governor thinks about it for a while,
contacts the President.
That doesn't happen anymore for many different reasons.
You'll see some of the improvements that we made,
and we need to be honest and candid
that we don't always get it right in these exercises.
The whole purpose of the exercise is to break the plan
so the plan becomes stronger and better with good assumptions,
so in Cascadia Rising Two scheduled for 2022,
we'll be taking that to the very next level.
-Very cool. -Very good.
-Right here. -Yes, sir.
-Oh, hi. In a major earthquake,
can you speak to the frequency and magnitude of aftershocks
so that, assuming we get the ShakeAlert system
working well for the first shock,
kind of segue off the other question too is,
in a major earthquake, can we not expect the system
to work very well for the -- an aftershock?
-Yeah, that's a great question.
The aftershocks are potentially a really key application
of something like ShakeAlert
because you have people in already damaged buildings,
ones where you're maybe right balanced
on that edge of life safety,
and you have the emergency responders
that have to decide whether to be in those places.
We know that, for a very large earthquake,
typically there is a relatively predictable
kind of sequence of aftershocks,
and, you know, kind of we expect an aftershock of a magnitude,
you know, one to several of a magnitude,
maybe one magnitude scale down from the main earthquake
but with a significant potential of an even larger earthquake
as sort of an aftershock.
Then we kind of redefine it as the main shock
and the foreshock but -- And then, you know,
drop down two magnitude, orders of magnitude.
You expect to go up by a factor of 10 of those,
another order of magnitude, even more,
so you expect hundreds of aftershocks,
and Anchorage saw this last year.
And the ShakeAlert system has the potential
to be incredibly helpful for those aftershocks,
but it also has challenges.
One is, when they were coming very, very frequently,
the system is going to be challenged
to distinguish individual events,
so in those first minutes
to hours after the earthquake when they -- You know,
it's sort of an exponential decay of aftershocks,
so when many, many events are happening,
that's going to be a challenge to the system,
and that's part of the technical work
that still goes on in refining it,
improving it, making sure it can really detect those events.
We hope though that it will become
a critical component of that,
and one of the products that the US Geological Survey
produces now for every significant earthquake
is an aftershock probability forecast
basically going forward,
and it even gets updated every day
or maybe more often than every day so that people --
And California saw this with the recent
Eastern California Ridgecrest sequence of earthquakes
where you're getting regular information
about the likelihood of an aftershock
in the next 24 hours, and, you know,
that set of earthquakes started with a 6.4, right?
And then the -- You know, it was stated that there was
non-negligible potential for an even larger earthquake
although typically aftershocks are smaller,
and in fact, we had the 7.1, what, 2 days later, 1 day later?
I forget. Yeah. -Days later.
-So that's actually a crucially important part of it
that I didn't get a chance to talk about.
-Perfect. -Yeah.
-Sir. -In the larger earthquakes
you guys have studied around the world
plus what we might expect here in the Subduction Cascadia,
a 9-point earthquake,
what happens with utilities in terms of natural gas
and sewer and water conveyance and electrical
and transportation infrastructure?
What have you seen happening? What survives the most?
What damages the most,
and what can we expect around here possibly?
-We've un-nominated all of ourselves as being the experts.
-So anybody in the audience want to take this one?
We're good with that.
-What I can say is, for instance,
I mentioned that our Seattle Public Utilities
recently did do a seismic-vulnerability analysis
of its entire system, where it draws its water from,
how it pipes it in, how it distributes, et cetera,
and I know that Puget Sound Energy
and other utilities are doing the same sort of thing,
but you should expect disruptions
to absolutely everything, and there are standards
just like John talked about for buildings.
There are standards for lifeline components
such as water delivery, telecommunications, fuel
and other things like that.
-Might want to add that, just to put a note
of one type of optimism on it, is that we've seen a number
of these very large subduction earthquakes around the world.
The ones that -- around magnitude 9
or high 8s are not very common,
but there's been a bunch of them,
and Erin talked about directivity.
An awful lot of them push their seismic energies
sort of from below the shoreline out towards the sea,
and that's good news,
and in fact, you know, we look at Japan in 2011, Chile in 2010,
go back to Alaska in '64.
You can look at a whole bunch of earthquakes,
and many times, these very largest earthquakes
because most of the shaking originates from offshore
are not as damaging as we might anticipate
for their scale from the earthquake directly.
That's not to say we're out of the woods at all,
but, you know, damage in real earthquakes is very patchy.
You showed buildings that were collapsed
next to other buildings.
I told you I experienced that Santa Cruz earthquake in 1989,
and I want to tell you that large parts of the city
were absolutely fine whereas a building,
a house could be off its foundation
and the one next door so fine
that the china didn't fall off the shelves, you know,
and that's just the nature of earthquake damage.
Chile, I think, after the Maule earthquake,
had a lot of things that went wrong,
but an awful lot went right,
and they really didn't have a very, very large loss of life
or even of property for the scale of the earthquake, 8.8.
Yeah.
-So I just want to follow up quickly.
I participated in a study the city of Mercer Island
did maybe a decade ago, and their concern was
that they were going to be out of water after a big earthquake,
and their concern was very warranted
because if you go under the East Channel Bridge of I-90
and you look up, all of the utilities
that feed Mercer Island are hooked to that bridge
and come from the east across that bridge span,
and I think, at the time, the bridge and maybe still be,
was designed to withstand about 30 percent G shaking,
and so they were very concerned that they were going to be
literally cut off of everything,
and so they redesigned their water tanks,
bolting them down and reinforcing them
to keep them from jumping around,
and they got a permit from the state
and the federal government to draw water out of
Lake Washington for firefighting.
Yeah, so it is kind of the thing of get to know where you live
and where your utilities are coming from
and make sure that --
-Very good. -Yeah, you make sure you know
that they might be able to make it through the earthquake.
Jim? -I'm James Bela.
I'm president and founder of Oregon Earthquake Awareness
in Portland.
I've been working on Cascadia for 27 years,
about as long as Erin Wirth has been alive.
Portland and Seattle have been in a century-long test of wills
to see who can prove first at,
if you do nothing, nothing happens.
When 1980 Steve Malone was looking at the helicorder at UW
when Mount St. Helens erupted in,
I put a quote from him in a article I wrote, 2014,
and he said,
"The lesson of Mount St. Helens is that, in some cases,
even the worst-case scenario can be exceeded,"
and what I would like to propose to Barb
is that how we got to now isn't working,
that what we really need as a community --
You can always hire people to do what it is you want to do,
so I believe we should have scenario earthquakes
to what we can expect in Seattle
both from Cascadia and from local faults,
like the Seattle Fault, like the Island Fault,
that people can use to build a community
to withstand the maximum earthquake on the Seattle Fault,
which is about the size of the recent earthquake in Alaska,
but until we have that, we don't know what we have.
-Mm-hmm.
-And maybe I'd like everyone on the panel
to explain to the audience what a 2,500-year earthquake
is because if we don't have to worry about that one,
what about the 5,000-year earthquake?
What about the 7,500-year earthquake?
What about the 100,000-year earthquake,
which we're about due for?
-Barb?
-I'll just start by saying I appreciate the comment,
and we do study earthquakes around the world.
Christchurch, New Zealand, is one of our sister cities,
and many of our staff members have been down there,
including our elected officials, and come home with the lessons
and understanding of the trauma
that a community like that goes through.
Our electric utility, Seattle City Light,
has tried to figure out, how do we do more microgrids
throughout the city so we're not quite as --
We're able to segment but not break
and be a little bit more resilient
in how we come back up again, but you're absolutely right.
If we're just thinking --
If we're staying at home and making this up in our head,
we're never going to test ourselves with the rigor
that we need to, to put really strong systems in place.
What is a 2,500-year earthquake?
-Brian is the man on that. Yeah.
Just to comment on -- I won't get into details
of how you sort of extrapolate to longer recurrence.
It's a huge research topic, whether Cascadia produces,
you know, just the same one sort of beat by beat over
and over again every 300 to 600 years,
whether there are long pauses
and then extra large earthquakes or not.
Those are big questions, some of which we won't have answers to
until we've waited a few thousand years to see,
but, you know, you can kind of look at this maximum size
of an earthquake that just the geometry of the fault zone
is capable of producing,
and it could be bigger than our current scenarios
but maybe only up to as much bigger as,
say, the 1960 Chile earthquake was,
so we kind of know things about what the --
at least the globe has experienced during this time,
and there are, of course, the black-swan event things
that are very hard to plan for.
You know, the biggest earthquake the planet
can have in 100,000 years
is bigger than what we've seen clearly,
but there is sort of a maximum scale.
We can't -- You know, despite Hollywood movies,
we're not going to get to a 10.5.
We're just not. Faults aren't that big.
Yeah, exactly.
-I'd like to add one comment on the building side of things.
When I talked about 500-year events
and 2,000-year events, when you look at that --
And this is my USGS colleagues providing us the information.
In that return-period time frame,
we look at all the different events
that could generate that kind of shaking,
so for us, that's about a 7.5 now in the Seattle Fault.
I thought it was 7.2 until tonight.
It's a magnitude 9 on Cascadia,
and it's about a magnitude 7 deep,
so in our design process here in the Puget Sound region,
even though we have a return period attached to it,
it has scenario-based shaking that we think about,
and the shaking I showed you for that building in San Francisco
was a magnitude-8 shaking on the San Andreas Fault
coming right at the building,
directivity thing, Erin, that you described,
so we do think about it in those terms of real scenarios
because if you keep this generic return period,
you got to think about real events
and what they will generate, what shaking they will generate
at the building site you're designing.
-Perfect. Yes, ma'am.
-Yes. Hello.
My question is for Engineer Hooper.
-Yeah. -What parameters
you take on consideration
to add a damper system in your building design?
-Okay. Okay.
What you're asking is more sophisticated technology
in helping to resist earthquake energy absorption.
That technology, called dampers,
has been around for quite some time.
The Japanese use it quite regularly.
We actually use it at Safeco Field.
The roof is supported that way,
and so is the Seahawks Stadium roof.
-T-Mobile. -Oh, T-Mobile, thank you.
Whatever.
I'm old-school, okay, Barb?
So anyways, we don't use that technology
as much as we perhaps could, but as I had mentioned,
as we look towards improving our performance measures
and we look at this thing called functional recovery
to help reduce damage,
I think that technology will become more important
because that's the way we'll need to go to help
reduce the damage to buildings
and get us back into buildings faster.
-Yes, sir.
-My question is a little bit more specific
and perhaps not answerable.
You've talked about scenarios and testing
under different building conditions.
I'm wondering about the floating bridges and the locks
and if any studies have been done about those structures
and, if so, what that might mean for us.
-The only one that I can specifically address
is the new 520 bridge,
and we were asked about that in terms of
if there's a big Seattle Fault earthquake
that produces a seiche in Lake Washington where the --
basically a big water wave where the wave is --
water is sloshing back and forth,
what should they look for in terms of a rupture
to design for, and how big a wave would that produce?
And they ended up settling, and I really almost hesitate
giving you a number because I'm surely going to be wrong,
but I think they settled on, like, a 12-to-15-foot wave,
and they built for that,
and that may have been changed in the final design,
but they did take that into consideration
for the new bridge.
The old bridges, I don't think they even took any of that
in the design to be quite honest.
-And the locks? -I don't --
-So we have talked with the U.S. Army Corps of Engineers
and toured the locks on what their emergency plans are.
It isn't that they're built to survive,
but they do have a contingency plan.
They've got -- They have the ability
to intentionally flood them with other materials,
which will screw things up for a very long time
but limit the amount of damage.
-Okay, and remember the locks were built over
100 years ago, right, guys?
Earthquakes didn't exist for us 100 years ago.
-Yes, sir. -Just following on that,
I was struck by our building engineer explaining
how we are getting so much new information
that codes keep getting revised, so I'm wondering --
Structures like the Space Needle or, you know, us old-timers,
the Seafirst building or, you know,
a lot of these skyscrapers that were built 20,
30 years ago, what in a 9.0 earthquake
might happen to some of these high-rises?
-Boy, is the camera off yet or what?
Clearly, we're progressing our technology
in our understanding of the earthquake hazard
and the shaking that can occur.
We have been designing for earthquakes
for this whole time frame,
and I have done some studios of some tall buildings
in Seattle that are older vintage.
Their reliability to perform well
is not quite as high as new building.
That's -- Rest assured, that's the case, but it's interesting.
In some of the buildings that we looked at
because of wind design pressures --
We design for wind, too.
The wind does blow here.
For tall buildings, is a big deal,
and you get additional strength of the building because of that.
What you don't have as good as I mentioned is the detailing
or the connection of the pieces together,
so that's not quite as resilient, so again,
I'd like to just describe it as it will do okay.
It's not as good as, say --
But just because the reliability isn't the same, it can't be,
and I can't put a quantification to that
because we haven't done enough detail studies
because each of those structures that were mentioned
are very, very unique obviously,
and it would take a detailed analysis
like I showed on my little video
to really understand how those structures might behave.
-I mean, the Space Needle is fairly simple.
I mean, what about that 1962 structure in a 9.0,
do you think?
-I don't know. I really don't.
I wish -- I don't want to make something up.
-Not to be risky or -- -Yeah.
-So I want to take these last two questions,
and then we're going to take a break,
and you can get a beer and go to the bathroom.
-I'm getting a beer.
-And we're going to stick around, so if you feel like --
If you want to ask other questions,
feel free to grab us and ask.
-Can I just make one more comment
to follow up on that last question?
So this -- -Did you study the Space Needle?
-No, no. -Okay.
-But I was going to mention that,
in terms of new buildings, I feel like the city of Seattle
and the cities of Bellevue have been very receptive
to new research related to earthquakes,
so in December 2018,
both of those cities actually updated their guidelines
for the design of tall buildings
based on the M9 earthquake simulations
and based in amplification that we were seeing
in those simulations, so for new buildings,
I think that actually we've been very good
about updating the design recommendations.
-And just, you know, that we were doing base before that too,
just not to the rigor that we found out from the M9 research.
-Yeah. -Yeah.
-And Jeff Berman was part of your M9 project at U Dub
has modeled the Space Needle, I think,
and I'm not going to say anything about the results
because I'm no engineer,
but there's work that's certainly been done to look at,
at exactly that question. -Oh, good.
I did not know that. -Sir.
-Lots of tremendously wonderful, interesting
and thoughtful information, so thank you for that,
but one comment that I heard that kind of has stuck with me
is the importance of networks,
community as part of the resilience profile.
I think we hear a lot about having food,
having water and less about that,
and I'm wondering if there's actually any research
about how other places that have functional communities --
You know, is there something that we could do collectively?
Is there some research to point at what works,
yeah, just to unpack that some more?
-There's an enormous library in Boulder, Colorado,
at the Natural Hazards Research Center
directed by Chief Executive Officer Lori Peeks,
and she's a good friend.
She's a wonderful colleague,
and we learn from many of her research scientists.
Again, we're not trying to make up
what we think we're going to experience.
These are people who go around and study
these things constantly.
And something else you said, we are influenced
by the international community as well,
so, like, I've been a member of the International Association
of Emergency Manager for years and years,
and so we're constantly hearing what did
and didn't work in Italy, in Japan, in Hong Kong,
in Chile, in Australia, et cetera,
so, yeah, there's a big body of research,
but I do recommend the Natural Hazards Research Center.
-Last question, sir.
-This one is for Professor Tobin.
You have many, many, many, many precise
GPS stations scattered throughout, and they are...
The good news: You've found
periodic seismic silent earthquakes.
The bad news, that you found period seismic --
What is this data telling you? What's it screaming at you?
What do you think you're going to get out of this?
-Yeah, so people have heard about the slow earthquakes
or what we call episodic tremor and slip,
and, you know, maybe people don't know that.
The same GPS that makes,
you know, your phone know where you are,
if you fix it to the ground and measure it continuously,
we can actually tell where that point on the ground
is down to sort of a millimeter or so and see how it moves,
so we're actually measuring plate motions.
It's not just sort of geology anymore.
But so what's happening is, right,
the points on the ground in Western Washington
typically are actually moving that few centimeters
a year towards the east,
and it's because the plates are stuck together,
but every once in a while,
the portion under sort of the eastern side of the Olympics
and just west of the Sound here
and up across Vancouver Island down into Oregon
decides for a couple of weeks to turn around
and move the other way for a little while,
and it slips a number of centimeters
and then stops again, and it's associated
with this stuff that I hesitate to even call tremor
because that makes everybody think of earthquakes.
It's actually sort of background seismic noise
at a very low level no one ever feels,
but we measure, you know, thousands of these tremor events
during one of these periods of slow slip.
It turns out they're on a different part of the fault
zone deeper down the fault
closer towards the direction of where I showed you
where the stuff comes from for the volcanoes
than the part that we're most worried about being stuck
and locked for the most part, we think, and so what happens
is though that that is moving the upper plate
just a little bit the wrong way or back towards,
and a hypothesis has been floated
and is being thought about that
that is adding a little bit of stress
to sort of the back end, you might say,
kind of kicking the bottom end of the subduction fault
in the place we don't want it to be kicked
because that could trigger an earthquake.
There is no -- I mean, this clearly has been going on.
It happens about every 14 months in our region
kind of like clockwork, and we got a little --
got lots of news-media interest this August when it happened,
but then it kind of turned itself off earlier than usual.
Yeah.
-Have they seen this anywhere else in the world?
-Oh, yeah, absolutely, so these kinds of events
are happening in Japan.
They're happening in a number of subduction zones
around the world and even on the San Andreas Fault
and other non-subduction faults.
I guess the bottom line to cut to the chase
is that there's some evidence
that sometimes big subduction earthquakes
are preceded by some sort of slow-slip event,
but many, many, many slow-slip events happen
without an earthquake that follows them,
so they're sort of like foreshocks.
You never know something's a foreshock
until a bigger thing happens after something you saw.
We don't have them as a predictive tool yet,
but we're certainly very interested
in studying those events.
-Perfect. Thank you, guys, very much.
Like I said, we're going to be here for a while.
Yeah. Thank you.