Seismo Blog

The Value of Citizen Scientists

October 14, 2020

by Steve Malone

Here at the PNSN we have been providing information on earthquakes and other things that go bump in the night via our web pages for about 25 years.  The products we offer have expanded and changed over the years as new capabilities have been developed and as new interesting signals have been analyzed.  Early in our web offerings in 1996 we provided lists and maps of earthquakes and within a couple of years, plots of seismograms we called “webicorders”. 

Some of our seismology colleagues at other networks warned us about showing original data.  They told us that amateurs would see these data and come up with all sorts of hare-brained interpretations and predictions and spread crackpot theories that would confuse the public and make extra work in order for us to counter with legitimate interpretations.  It turns out that these warnings were not needed.  It is fairly rare that such off-the-wall interpretations or predictions require us to react. In fact, in the 1980s and 1990s we often had to correct the news media when they would report on some hare-brained idea of goats or headaches predicting earthquakes or volcanic eruptions.  Now the media can see the original data, read explanations online from reputable sources and not get caught up in spreading totally bogus predictions.  That is not to say that there are not people out there with outlandish theories and predictions.  Social media channels are ripe with these.  Some have their own web pages and even try to monetize their ramblings by selling predictions to gullible fans.  However, this note is not to dwell on this aspect of the citizen non-scientist but rather the very valuable contributions that the real citizen scientists provide to us and to science in general.

From time to time people out there in the web world write to us <> or comment on social media (  or on Twitter: ( with questions or comments on what they see (or don’t see) on our web pages.  Another place to engage in more in-depth discussion of all manner of PNW earthquake topics is the Pacific Northwest Earthquake Discussion Group on Facebook ( Unfortunately some questioners are reacting to what they have read from crackpot social media channels and are asking for our explanations rather than being willing to do their own research by looking at reputable web pages and going a bit deeper.  While we do try to help with legitimate questions, too often our answers are to reiterate previous explanations.

That being said there are more than a few cases where the questions or comments have been very insightful and useful.  It never hurts to get a different set of eyes on our data and analysis.  Science is often advanced by questions being asked when something doesn’t seem to make sense to new observers.  I will give a few recent examples of such cases.


1. Several months ago one of our regular followers sent an e-mail note <> about our tremor detection and mapping system producing no locations for several days.  J McB often asks us questions about tremor because he watches our products frequently.  (J McB is fairly self-effacing in claiming he is no scientist, but, while he is perhaps without a formal scientific education, I think, based on his comments and questions, he has all the hallmarks of a curious and critical thinker, exactly what it takes to be a good scientist).  



My first reaction to his observation of “no tremor for three days” was to think, “This happens from time to time so no big deal.”  However, I did look more closely at some of the intermediate analysis products and found evidence of a subtle problem with much of our realtime seismic data.  In fact, while subtle, it probably was affecting other parts of our automatic analysis systems.  I immediately sounded a “red alert” to our technical staff resulting in all hands on deck to find and deal with the problem.  For almost two hours a team of computer systems analysts, programmers, seismic analysts and seismologists, all coordinating over a zoom session, searched for, found and fixed the problem.  Since it had been going on for several days, it required us to go back and look more carefully at all previous automatic analysis and do some minor adjusting to our catalogs and products.  Thanks to this citizen scientist asking an insightful question our problem was relatively short-lived.


2. On the afternoon of May 15, 2020 our FaceBook Group ( came alive with a series of posts about feeling an earthquake near Spokane, WA, but nothing was reported in the PNSN recent events catalog (  After several hours of confusion about what had or had not occurred, problems with the PNSN automatic system and even our review and analysis procedures were unraveled and our catalog was updated.  A later post by Patty T summarizes the confusion thus:

“Today at 2:50 PM Quake Feed registered a 2.9 in Royal City, WA 155 miles away (from Spokane).  Locals felt a large boom heading from Spokane Valley to Idaho.  7 hours later they confirmed an earthquake in Mean, WA 25 miles away (from Spokane).  The location took 7 hours to confirm and changed by 225 miles (sic).  It was changed on the Quake Feed app. 
Is this perfectly normal, and I’m misunderstanding how they are detected or the precision?  It seems odd and…”

While the real problem was originally generated by technical problems at the PNSN (see below) the confusion illustrated on the many FaceBook group posts did get our attention and caused us to try and track down what was really going on.  Some of the confusion was exacerbated by our former Director, Dr. John Vidale, who was trying to explain why a small earthquake near Royal City could not possibly be felt near Spokane.  After the problem was found and we posted a revised catalog John kindly followed up with the following post the next day:

Yes, color me embarrassed.

I'd note, however, that this is in the under-covered far eastern region of Washington, the event was clearly recorded anyway, and there was a fairly rare sequence by which the automatic location misled whoever first took a closer look. So we're glad you persisted, do point out and question inconsistencies. I'm actually not aware of any previous instances of missing a felt earthquake in the PNSN authoritative region for many hours.

Indeed the PNSN was even more embarrassed but equally thankful for our “fans”  asking the questions that got us looking more carefully.  Following are the nitty gritty details of what and why things went wrong.

To start with earlier on May 15 there had been a Mag=6.4 earthquake in central Nevada with a very vigorous aftershock sequence.  While these earthquakes are outside the PNSN authoritative region their seismic waves showed up on many of our network seismic stations.  Our automatic detection system triggered and recorded many of these events for later manual analysis.  Our computers are also programmed to “pick” the times of first arriving seismic waves and try to compute locations and magnitude estimates automatically.   Of the more than 600 earthquakes that the authoritative Nevada network reported on May 15 in this sequence we triggered on 43 and ultimately manually analyzed 14 of the larger events along with 28 events within our authoritative region. That is to say our seismologists were very busy.  When the automatic system reported a local earthquake near Royal City our duty seismologist glanced at the location and presented waveforms and confirmed it was a valid earthquake and could be published on our web catalog.  Here are the waveforms presented:

At first glance there would be no reason to suspect that the computer got it terribly wrong.  Because of a mix of seismic arrivals from the real earthquake that was near Spokane and the more distant earthquakes in Nevada the computer got fooled.  After seeing the confusion rampant on our FaceBook Group we started digging deeper.  After reviewing other ways of looking at seismograms and re-loading selected traces into our analysis programs we could see that stations closer to Spokane actually had good arrivals earlier than those near Royal City.   Here is the equivalent set of more appropriate waveforms:

Manual re-analysis of these additional data resulted in a location 15 miles NE of Spokane.  Even then the location cannot be determined with as much accuracy as those in other parts of the Pacific Northwest, because we have no seismic stations close by. We probably would have eventually found the bogus location and corrected it during the final analysis step of our procedures, but because the Citizen Scientists raised questions about our catalog right off, we were alerted to an issue sooner than later.  The 338 people reporting this earthquake being felt near Spokane through the DYFI page (see below) would have surely alerted us to a problem eventually.



3. A couple of weeks ago (Sep 23) Lisa H. sent an e-mail to us inquiring about the colors of our Near-Real-Time plots ( and something that seemed to be lots of “tremors”.  By the way, the colors have no significance; they are just to aid the eye in differentiating the different traces.  These sorts of plots are generally not that great for interpreting what is happening. The plot is only ten minutes long, cannot be re-created and is for stations that are very far apart from one another.  It is really only somewhat interesting just after a relatively large event takes place, so that one can watch the seismic waves arrive at the different stations over time.  Here is a copy of the plot that Lisa sent to us:


Yes, it looks dramatic, but it turns out that all of that apparent shaking is just from one station, SHW. A glitch in the plotting routine introduced a hole in the data for most stations for a short time.  When I first looked at this I knew a major rain/wind storm was going on at this time and first thought it was just “wind” noise (ground shaking due to wind gusts).  But I decided to look closer and realized that SHW was very strongly affected as well as some other stations on and near Mount St. Helens, while stations away from the mountain only showed low “wind” noise.  These signals actually came and went over a period of a couple of hours.  Here is a more traditional “webicorder” record of several hours around this period at SHW (Time on the left is in GMT which is 7 hours ahead of local PDT).  This is followed by a set of seismograms one hour long for five stations at Mount St. Helens,  (SHW, STD, and EDM are on the flanks, HSR is high on the south side and VALT is in the crater).



Looking at these records I knew it was something much more than just wind and more likely some sort of flood or mild debris flow signals.  I contacted our colleagues at the US Geological Survey Cascade Volcano Observatory (USGS CVO), and their lead seismologist, Wes Thelen, reported that they knew about this event right off.  In particular they have special, high-frequency seismographs called “Acoustic Flow Monitors” (AFMs) that had reported debris flows during this period in both the North Fork and the South Fork of the Toutle River.   Wes sent me a plot showing the level and timing of these signals.


Debris flows can be generated when heavy rain falls on slopes with little vegetation and loose soils, as is typical on the slopes of Mount St. Helens.  Such events are expected from time to time, and thus CVO is primed to detect and interpret them.  While CVO knew about these events right off it took a Citizen Scientist to call our attention to something unusual before we dug into it enough to understand what was going on.  This seemed to get enough public attention that KOMO-TV even wrote up a blog-post on it.

The PNSN staff are very busy installing and repairing seismic stations, reviewing data, doing research and producing any number of products including some seen on our web pages.  While we do check on the many automatic web products from time to time it is very handy to have other sets of eyes on them.  There are many cases other than those listed above where Citizen Scientists have either called attention to something that seems broken or doesn’t seem right, or they just see something out of the ordinary.  While some questions could be answered by just digging a bit deeper in our many different web pages we are very happy to try to answer those that have not been answered elsewhere and are particularly happy when problems with our web pages are pointed out so that we can try to fix them.


An overview of slow slip (and tremor) in all of Cascadia - more study needed.

St Helens 40th Anniversary Program

May 11, 2020

by Bill Steele

The PNSN anniversary presentations is available on line for viewing at::
Three hundred and twenty years ago, thousands of coastal residents settled in for the night on January 26th 1700, when suddenly the ground began to shake.

Small earthquakes near Fall City

December 19, 2019

by Steve Malone

A magnitude 3.4 earthquake near Fall City the evening of Dec. 18 has been followed by a few aftershocks, one of which had a magnitude of 3.0.

SoundersFC Soccer Shake Experiment

November 8, 2019

by Steve Malone

The PNSN plans to monitor the MLS Cup Finals in Seattle on Sunday, Nov 10, 2019. Return to this blog for updates as the experiment is installed and gets underway.
Help us figure out how Seattle’s unique geography affects earthquake shaking.

Ml=4.6 Monroe Earthquake of July 12, 2019

July 19, 2019

by Steve Malone

Additional Info is available for this earthquake, via its event page.

Typical Mount Hood Earthquake Swarm

July 9, 2019

by Steve Malone

The swarm that started late on July 7 really got hopping on July 9 at about 9am PDT (16:00Z). This swarm looks similar to previous ones near Mount Hood.

An updated tremor monitoring system

May 21, 2019

by Aaron Wech

A completely redesigned tremor location program and web interface is now available. The hourly tremor plots have been discontinued.

OOPS - Correction to last post

April 11, 2019

by Steve Malone

I made some significant errors in my last post on ETS. I try to correct these here.

When is an ETS just T

April 8, 2019

by Steve Malone

Current ongoing Puget Sound deep tremor is probably NOT a real, classic ETS. There are several reasons why we think so.

March 2019 Washington Tremor

March 29, 2019

by Mouse Reusch

To be tremor, or not to be tremor. That is the question...

Earthquakes and Volcanoes; Warnings?

March 14, 2019

by Nicholas Park

Comparing earthquake and volcano early warning systems from a lay perspective.
We have removed our seismic stations from the Rattlesnake Ridge landslide even though it continues to slowly move.

Come for the pretty pictures, stay for the science.

November 30, 2018

by Alex Hutko

Sea monsters, beautiful waves, and twitter scientists.

Something Scary at the PNSN just before Halloween

October 29, 2018

by Steve Malone

Our primary operating computer system will be changing hardware and some software on Oct 30.

Current ShakeAlert Implementation and Partners

October 19, 2018

by Elizabeth Urban

Following this week's Great ShakeOut Earthquake Drill, we thought it would be appropriate to talk about the local progress in earthquake early warning.

Rattlesnake Ridge Landslide slowing down

July 9, 2018

by Steve Malone

Update Aug 5, 2018. From 180 tiny events/hour back in March the landslide is producing only about 100 events/hour now. Update Aug 5, 2018.

MSH Anniversary Media Round-Up

May 18, 2018

by Elizabeth Urban

A collection of news stories on the 38th anniversary of the Mount St. Helens eruption
The final blog about The M9 Project is going to focus on you. What are you going to experience during a megathrust earthquake? How do we connect science and community? What should you do to be prepared?

Landslide Study with Nodal Seismographs

March 26, 2018

by Amanda Thomas

A special seismic array for studying the RattleSnake Landslide. March 26, 2018

Seismology in the air

March 22, 2018

by Steve Malone

A bolide explosion off the coast is recorded on many seismic stations allowing us to get an approximate location.

Continued Landslide Monitoring

February 11, 2018

by Steve Malone

Steady landslide motion still of seismic interest. Update on March 26, 2018

January 2018 Oregon Tremor Event Update

January 31, 2018

by Nancy Sackman

Oregon tremor over!

December 2017 Oregon Tremor Event

December 15, 2017

by Nancy Sackman

December 2017 Oregon Tremor Event


Over the past 9-10 days, it appears that tremor in central Oregon has picked up (Figure 1).  The last slow slip and tremor event was in February 2016, 22 months ago.  


Figure 1

Figure 1. Age progression of tremor in central Oregon for the past 9 days.  Earliest tremor locations start from 12/5/2017 and propagate roughly outward, clustering near Salem and Roseburg.  Last update was December 14, 2017.


Tremor is the release of seismic noise from slow slip along the interface of the Juan de Fuca and North American plates and lasts for several weeks to months.  This process is known as Episodic Tremor and Slip (ETS).  Slow slip happens down-dip of the locked zone (Figure 2).  The locked zone is where tectonic stress builds up until it releases in a great earthquake or megaquake.  The recurrence interval of slow slip and tremor varies at different regions along the Cascadia Subduction Zone.  


Figure 2

Figure 2. Cross section of the subducting Juan de Fuca Plate.  Figure from Vidale, J. and Houston H.  (2012) Slow slip:  A new kind of earthquake (Physics Today, 2012 pages 38-43).


The last ETS event in Cascadia started in February 2017 around the western edge of the Olympic Mountains.  The duration was approximately 35 days with a two-week quiescent period.  Prior ETS events in northern Washington/Vancouver Island area was approximately December 2015.  


The last ETS event in central Oregon was 2016 and lasted just over a week before it stopped on March 1, 2016.  


ETS events are still being studied to understand the processes about slow slip and megathrust earthquakes.  

More information about slow slip and tremor can be found here on the PNSN website.

December 2017 Oregon Tremor Event - Update

December 27, 2017

by Nancy Sackman

Tremor has continued in Oregon since the last post on December 15th.  Current tremor activity has been ongoing since about 12/5/2017 (figure 1).  


Figure 1

Figure 1. Age progression of tremor in central Oregon for the past two weeks.  Earliest tremor locations start from 12/5/2017 and propagate northerly and southerly.  Last update was December 26, 2017.


Since December 19th, tremor has now migrated northerly toward Portland and southerly toward Medford (figure 2).


Figure 2

Figure 2. Tremor activity from 12/19 to 12/26 showing progression in a northern and southerly direction.

More FAQs on Slow Slip and Tremor


On our previous blog post, we briefly discussed what ETS (episodic tremor and slip) is.  Let’s go through a couple of more frequently asked questions.


1.What is tremor?


Tremor in the Cascadia Subduction Zone is the seismic noise of slow moving earthquake along the interface of the subducting Juan de Fuca Plate and the North American plates.  Compared to normal earthquakes, tremor has lower frequency energy and can last for minutes, hours or weeks.


2. What about volcanic tremor?


Tremor can also be volcanic.  But ETS is deep, non volcanic signatures that are a result of plate motion, not magmatic movement.


3. How deep are the tremors?


As it states on our website - “This is a topic of ongoing research.”  But research suggests that it occurs near the plate interface at approximately 30 - 40 km deep.   


4. What is the magnitude of tremor?


Tremor is probably made up of many tiny individual earthquake-like sources each with a "magnitude" of less than 1. Since tremor is an on-going continuous signal assigning a magnitude to it is never done.  


Check out the map on our web page:


In the previous blog post about The M9 Project, we talked about how the Cascadia Subduction Zone can generate an M9.0 earthquake. However, our understanding of what an earthquake of this scale would actually look like is less advanced. While we have evidence of past earthquakes (e.g., native oral histories, tsunami records), we have no quantitative observations of how strong the shaking would be during a megathrust earthquake in the Pacific Northwest.

To address this problem, researchers with The M9 Project used 3D computer simulations to help understand what 50 different realizations of an M9.0 earthquake could look like in Cascadia. To create these simulations, The M9 Project researchers used multiple supercomputers: Stampede (University of Texas - Austin), Constance (Pacific Northwest National Lab), and Hyak (University of Washington). A single earthquake simulation took up to 46 hours to complete. If it was possible to run these earthquake models on a personal computer (many of which have a mere 2 processors, compared to the 576 processors used to run these simulations on a supercomputer), it would take about 522 days to complete one simulation.


Why are earthquake simulations important?



The unique properties of the Cascadia Subduction Zone prevents a side-by-side comparison between a future Cascadia earthquake, and other earthquakes that have occured around the world. For instance, an M9.0 earthquake in Japan, Chile, or Indonesia may look very different from an M9.0 in the Pacific Northwest.


Scientists have developed equations that can estimate the strength of ground shaking based on an earthquake’s magnitude and a specific location’s distance from the fault. However, these equations still rely on averages, and do not fully account for location specific 3-D effects (i.e., “How will seismic waves bounce around in the Seattle basin?”). Conversely, the supercomputer earthquake simulations, while still having some unknowns, can estimate shaking at every point in the Pacific Northwest, and are specific to the geologic conditions of the Cascadia Subduction Zone.



How are these earthquake simulations created?

Out of an infinite number of possibilities, 50 simulations of an M9.0 earthquake were run by The M9 Project team. The individual earthquake scenarios had a few important variations between them, that made each earthquake source unique:  (1) the hypocenter location (i.e., where the earthquake starts), (2) how far inland the rupture extends (i.e., how close the earthquake gets to major inland cities, such as Seattle), (3) the location of “sticky patches” on the fault, that generate the strongest ground shaking, and (4) the slip distribution on the fault (i.e., how far certain areas on the fault move during the earthquake).


Are certain earthquake scenarios “better” or “worse”?

The area affected by a megathrust earthquake is large enough that the outcome is going vary by location. A “best-case” scenario for one area in the Pacific Northwest could be a “worst-case” scenario somewhere else in the region.

One of the results of the computer simulations showed that when an M9.0 earthquake occurs on the Cascadia Subduction Zone, less violent shaking may be felt closer to the epicenter. This is because an earthquake on the Cascadia Subduction Zone will not occur at a single point -- instead, it will rupture a very large area. As the rupture moves along the fault, the seismic waves will start to “pile up,” similar to the Doppler Effect.


As the waves at the front of the rupture combine, their amplitudes get larger and create more violent ground motion. Therefore, locations closer to the hypocenter may receive less complex and destructive seismic waves than locations that are farther along the rupture and experience this “piling-up” of seismic energy.

In these two videos, notice how Seattle's mock seismogram has larger spikes (which denotes stronger ground motion) when the earthquake source is farther south, and the fault ruptures north.



This variation by location makes it virtually impossible to award a scenario the title “best-case” for the entire Pacific Northwest.


Can we do even better?

These computer simulations are the most accurate representations of what an M9.0 earthquake would look like in the Pacific Northwest. Unfortunately, there is a lot of variability in these calculations because there are still too many unknowns. An increase in seismic and GPS instrumentation throughout the Pacific Northwest, especially offshore, will help us identify more specifics about the Cascadia Subduction Zone and improve future computer simulations. For instance, we may be able to determine where “sticky patches” are located on the fault and obtain a more detailed image of the 3D structure of the subduction zone. Further constraining these variables in the computer simulations will ultimately help us refine our estimates of seismic hazards in the Pacific Northwest.


Special Thanks To


Dr. Erin Wirth, UW Affiliate Assistant Professor



M9 Simulation coverage from UW News


50 simulations of the 'Really Big One' show how a M9.0 Cascadia earthquake could play out - Hannah Hickey


Flickr Album

We are going to have The Big One. That’s a fact.


The final blog about The M9 Project is going to focus on you. What are you going to experience during a megathrust earthquake? How do we connect science and community? What should you do to be prepared?


The Next Stages of The M9 Project


Seismologists are not the only contributors to The M9 Project. Civil engineers, urban design and planners, statisticians, social scientists and public policy researchers also play a role in determining earthquake risk, safety measures, and public response to hazards.


Understanding the hazards and mechanisms of an earthquake is one thing, communicating effectively to the public is a completely different ball game. The next steps of The M9 Project focus on how we define and discuss hazards with communities.


For example, how does the way we design hazard maps affect how communities approach hazard planning? (See photo below) Or, how can hazards planning be steered towards rebuilding to community-specific values?



From assessing the utility of hazard maps (see image below), to hosting community planning workshops , The M9 Project’s research into “long term” preparedness- mitigation, response, and recovery focuses on how to best help you. We will discuss what to expect when the big one hits, as well as some resources so you can take steps to prepare .


Learning about Cascadia from other Large Earthquakes


The last megathrust earthquake on the Cascadia Subduction Zone occurred in 1700 AD, before written records were kept in the region. In addition to The M9 Project research at UW, we can also look to observations of other major earthquakes worldwide, to help us predict what The Big One may look like in the Pacific Northwest.


Ground Shaking


A magnitude 9 earthquake will generate very strong shaking for several minutes. The intensity, measured by the Modified Mercalli Intensity Scale (MMI), is determined by observations during an earthquake. Shaking tends to decrease farther away from the fault and will vary with local soil conditions, so intensity will vary by location. A more detailed description on intensity can be found here.


Below is a comparison of the shaking intensity from the 2001 Nisqually earthquake, compared to a hypothetical  M9.0 earthquake scenario. A megathrust earthquake will be felt over a much larger area, and generate stronger shaking.




You can find more about how magnitude and intensity are related here.


As part of The M9 Project, UW civil engineers are researching building response to strong ground shaking from a magnitude 9.0 earthquake in Seattle. This video from Kinetica Dynamics shows skyscrapers in Tokyo shaking from the 2011 M9.0 Japan earthquake.





Large earthquakes on a subduction zone are capable of generating large tsunamis. For example, the 2004 M9.1 Sumatra earthquake resulted in a 30+ meter high tsunami on the west coast of Sumatra (source). For more about tsunamis, visit our tsunami overview page.


This NOAA video models the tsunami from the 1700 Cascadia earthquake, which caused damage and loss of life as close as the west coast of North America, and as far away as Japan.  



We expect the next great Cascadia earthquake to be similar. As mentioned in our first M9 Project blog post, the record of past megathrust earthquakes can be found in muddy estuaries on the coast of the Pacific Northwest. In the layers of coast that have subsided and been filled again, there are bands of sand brought inland by tsunami waves, time and time again. Here is a article written by the American Museum of Natural History with more information on the Ghost Forests on the PNW.




For liquefaction to occur, three things must happen. (1) Young, loose and grainy soil (2) needs to be saturated with water, and (3) experience strong ground shaking. The USGS, in coordination with California Geological Survey, give a summary of liquefaction and its effects here.


This video from the 2011 M9.0 Japan earthquake shows dramatic cracks in the ground, as well as liquefaction.



Our webpage on liquefaction includes video of the 2011 Christchurch earthquake, as well as links to liquefaction hazard maps for Washington and Oregon.




Strong shaking can increase susceptibility to landslides.


This blog from the American Geophysical Union details some of the significant landslides in Paupa New Guniea that were triggered by a M7.5 earthquake on February 25th, 2011.


The Pacific Northwest is susceptible to landslides due to seasonal conditions, and strong shaking will increase landslide risk. Here are some resources from the states of Washington and Oregon.


Building Damage and Fires


The 1989 Loma Prieta earthquake caused widespread damage to infrastructure, such as the collapse of the Cypress Viaduct in Oakland, and fires in the San Francisco area.


Major cities in the Pacific Northwest would be just as susceptible to fire damage, and the construction of the Cypress Viaduct bears a striking resemblance to Seattle’s Alaskan Way Viaduct.



So, What Can I Do?


In order to prepare effectively, it is important to be aware of all earthquake-related hazards, such as the ones listed above. The following websites are great resources for earthquake hazards and preparedness in the Pacific Northwest. We encourage you to know your risks, be prepared, mitigate against hazards, respond safely, and enagae in holistic recovery planning.


In the event of an earthquake, don't forget to drop, cover and hold!


Special Thanks To


Dr. Erin Wirth, Affiliate Professor, University of Washington

Lan T. Nguyen, Doctoral Student, Interdisciplinary Urban Design and Planning, University of Washington



MSH Anniversary Media Round-Up

May 18, 2018

by Elizabeth Urban

On May 18th, 1980, at 8:32 AM, the landscape in Southwestern Washington was forever changed by an explosive eruption of Mount St. Helens. This was the most deadly volcanic event in US history. 

Mount St. Helens is part of the Cascade Range, a chain of volcanoes from British Columbia to Northern California. The PNSN and the Cascades Volcano Observatory cooperatively operate 21 seismometers on or near Mount St. Helens, the most historically active volcano in the Cascade Range.

Seismogram of May 18th from one of our seismic stations. 

Main PNSN Page on Mount St. Helens

Main CVO Page on Mount St. Helens


On the anniversary of the eruption of Mount St. Helens, earth science gets its day in the spotlight. Here's a collection of news stories about the eruption and what we have learned about volcanoes since 1980.

38 years later: What's changed since the Mount St. Helens Eruption? 
- Q13 News 

Features an interview with PNSN DIrector Emeritus Steve Malone


Mount St. Helens: Remembering the deadliest U.S. eruption 38 years later
- USA Today, King 5 News

Summary of events on May 18th, 1980 with photo galleries

Lessons Learned: Mount St. Helens to Kilauea
- King 5 News

Interview filmed in the PNSN Seismology Lab with Director Emeritus Steve Malone


Remembering Mt. St. Helens as Cascade event looms
- KOIN 6

Event overview, brief discussion of Cascade hazards, and dispels concern of a Kilauea-triggered event in the Cascades.

Photos: The Mt. St. Helens eruption of 1980
- KOIN 6

Includes an interview with CVO Scientist-In-Charge Seth Moran


Scientists Reflect on the Catastrophic 1980 Mount St. Helens Eruption
- Ashley Williams, AccuWeather

Details about the activity that led to the eruption, how life in the MSH area fared, and another Steve Malone feature. 


How Dangerous are the Northwest's Volcanoes?
-KUOW, Oregon Public Broadcasting

Interview with CVO Scientist-In-Charge Seth Moran, discusses Oregon volcano hazards

Current ShakeAlert Implementation and Partners

October 19, 2018

by Elizabeth Urban

Following this week's Great ShakeOut Earthquake Drill, we thought it would be appropriate to talk about the local progress in earthquake early warning. Below is a summary of of our partners for pilot projects in Oregon and Washington.

Impact of Oregon ShakeAlert Pilot Partnership Projects

Lucy Walsh


Eugene Water & Electric Board (EWEB)

  • Eugene Water & Electric Board provides water and electricity to 200,000 customers in Eugene, as well as parts of east Springfield and the McKenzie River Valley.  EWEB is Oregon's largest customer-owned utility.
  • EWEB owns and maintains 800 miles of water pipes, 9 power generating facilities, 16,000 power poles and transmission towers, and 13,000 miles of power lines.
  • The Leaburg Canal pilot project will enhance protection for a 1920s-era earthen power canal that is seismically vulnerable to earthquake-triggered landslides from steep slopes above the canal and potential instabilities of the constructed embankments. Automated dewatering of the canal can prevent canal breaches that might follow heavy shaking, protecting residential properties located between the canal and the McKenzie River. A canal breach could impact several hundred residential properties neighboring the canal.   The potential costs associated with canal breach damage could easily reach tens if not hundreds of millions of dollars.
  • The Carmen-Smith pilot project will reduce the potential for earthquake damage to hydroelectric turbine-generator equipment at the Carmen Power Plant. Automatic closure of turbine shutoff valves and a power tunnel intake gate could prevent heavy damage to equipment and associated infrastructure. Preventing or mitigating damage to this critical power generating facility would position EWEB to return electric power to tens of thousands of customers sooner than might otherwise be possible if major equipment repairs were first necessary. The potential costs associated with repairing major damage to power generating equipment could approach 100 million dollars and take multiple years to accomplish.


Bridge Section, Oregon Department of Transportation (ODOT)

  • Oregon Department of Transportation serves all the citizens of Oregon and those traveling through Oregon. Over 36 billion miles were driven by all motorists on Oregon public roads and over 5.2 Billion miles were driven by domestic and international freight trucks on Oregon public roads (Oregon Trucking Association, 2018).
  • In Oregon, there are nearly 3.1 million licensed drivers and roughly 4.1 million registered vehicles; of those, about 3.2 million are passenger vehicles (Oregon DMV, 2018).
  • ODOT delivers a $6B budget in the form of capital improvement and maintenance of the highway system and works with cities and counties (local agencies) to oversee the use of $105 million in federal funds for capital improvement and maintenance of the local agency road systems.
  • Automatic triggering of warning lights on critical, heavy trafficked Oregon bridges not designed for seismic loads, and signaling to take alternate routes on can prevent life safety hazards for pedestrians and motor vehicles. Long-span bridges under the ODOT pilot project include the Interstate 5 Bridge (Portland), the Astoria-Megler Bridge (Astoria), the Yaquina Bay Bridge (Newport), the McCullough Memorial Bridge (Coos Bay), and the Isaac Lee Patterson (Gold Beach).
    • The I-5 Interstate bridge connecting Portland, OR to Vancouver, WA can see hourly traffic volumes upwards of 5,000 vehicles (SW Washington RTD, 2016)
    • Annual average daily traffic (ODOT Transportation Development Division, 2015)
      • Isaac Lee Patterson Bridge, Gold Beach = 6,200 vehicles
      • McCullough Memorial Bridge, Coos Bay = 13,600 vehicles
      • Yaquina Bay Bridge, Newport = 17,000 vehicles
      • Astoria-Megler Bridge, Astoria = 8,200 vehicles
      • Interstate 5 Bridge, Portland = 132,300 vehicles



  • Syn-Apps provides software solutions for delivering mass emergency alerts across an entire business’ communication platform. Auto notification can warn all Syn-Apps customers of impending shaking and provide them the ability to protect their people and their business’ physical assets.
  • Emergency alerts sent from the Syn-Apps Revolution software to indoor IP speakers, outdoor loud horns, digital signs, mobile phones, desktop computers, strobes / beacons, IP desk phones, etc. can be heard or seen by potentially thousands of people located on premise. In addition, organizations can alert people that may be located off-premise by external notification sources such as push notifications to cell phones, SMS text messages, email, or automated dial phone calls.
  • Syn-Apps provides alerting software to 46 companies across 27 cities in Oregon, and to wherever those businesses install the Syn-Apps software (“end points”).  Syn-Apps estimates they have licensed more than 23,000 endpoints in Oregon alone. Syn-Apps also delivers alerting software to customers across the nation, including 270 customers in California and 55 customers in Washington, and 35+ countries.   
  • K-12 education makes up a large portion (~25%) of the Syn-Apps customer base.


Central Power Station, Utilities & Energy Department, Campus Planning & Facilities Management, University of Oregon

  • The Central Power Station (CPS) is a District Energy provider, providing electrical power, heating steam, and chilled water to over 80 large buildings on the UO campus through 5 miles of concrete tunnels, servicing 29,500 students and staff on campus.  
  • UO has the ability to transmit electrical power to the local utility EWEB, and is therefore a potential emergency power source for nearby city government, law enforcement and hospital buildings and up to 100,000 residents
  • Automatic alert signals integrated into the control systems can prevent life threatening conditions, minimize steam ruptures or flooding, as well as minimize the time and cost of restoring critical systems.  Future applications will potentially protect students and staff across campus through a visual notification display.
  • Additionally, automatic actions on critical chilled water and natural gas systems can protect critical university functions, such as computing servers and sensitive research.
  • Approximately 23,000 students are enrolled and 6,500 people are employed at the University of Oregon.  51% of students are from Oregon; 37% of are out-of-state; 12% are international.


Oregon-based RH2 Engineering Partnerships

RH2 Engineering an engineering firm specializing in utility and infrastructure work for municipal clients throughout the Pacific Northwest, known for designing and implementing municipal control systems and emergency response plans for both water and wastewater utilities. RH2’s industrial-grade Advanced Seismic Control (ASC) device receives the ShakeAlert warning signal, translates it into time to shaking and predicted intensity, and triggers automated actions. RH2 has implemented over 50 customized automatic control systems throughout various municipal water supply systems in the Pacific Northwest. These systems are known to be reliable and robust.


Department of Public Works, City of Grants Pass, OR

  • The City of Grants Pass owns and manages a water supply, treatment and distribution system for 40,000 citizens.
  • The system consists of a surface water source, a water treatment plant, 8 treated water storage reservoirs, 13 pump stations, and 188 miles of water distribution mains.
  • Initially, use of the ShakeAlert signal will notify City public works staff to get to safety and to isolate water in the City’s largest water reservoir, preserving it for post-event recovery for thousands of citizens. Future phases will likely protect additional equipment (such as all pump stations and treatment plant process equipment in both the water and wastewater treatment plants), and notify all City staff to get to safety.
  • Shutting down motorized equipment prior to actual shaking occurring can save roughly $200,000 of equipment. Though difficult to predict, cost savings due to reduced fire risk from shutting down power at facilities could range in the millions of dollars.

Public Works Department, City of Albany, OR

  • The City owns and operates a water system and wastewater system to serve approximately 53,000 City customers, as well as the adjacent communities Millersburg and Dumbeck Lane Water District.
  • The City’s joint water system consists of 2 shared surface water sources, 2 water treatment plants, 7 treated water storage reservoirs, 6 pump stations, and 290 miles of water distribution main. The wastewater system is comprised of over 200 miles of sewer main and 14 lift stations delivering wastewater to the jointly owned Albany-Millersburg Water Reclamation Facility.
  • Automatic isolation of water in a critical storage reservoir will preserve water for post-event recovery. The City will also use the signal to notify public works operations staff for further actions at facilities, possibly including the water and wastewater treatment plants, the 6 pump stations, 14 lift stations, and additional reservoirs.
  • Protection of this equipment could save in the range of hundreds of thousands of dollars. Though difficult to predict, cost savings due to reduced fire risk from shutting down power at facilities could range in the millions of dollars.

City of Gresham, OR

  • The City of Gresham owns and manages a water supply and distribution system for 70,000 citizens, with assistance from two contracted partners.
  • The Gresham water system includes 9 pump stations, 7 water storage reservoirs, and miles of cast iron and ductile iron water mains.
  • Automatic notifications will alert public works operations staff for potential actions at facilities, including automated shutdown of motorized equipment at the water treatment plant, the 9 pump stations, and some of the reservoirs.
  • Protection of this equipment could save in the range of hundreds of thousands of dollars. Though difficult to predict, cost savings due to reduced fire risk from shutting down power at facilities could range in the millions of dollars.

South Fork Water Board (SFWB)

  • The South Fork Water Board supplies drinking water to over 100,000 people in Oregon City, West Linn, and some unincorporated areas of Clackamas County.
  • The SFWB owns and manages a water supply system consisting of a large intake and pump station on the Clackamas River, an advanced water treatment plant, 2 treated water storage tanks, 1 major pump station, and several miles of transmission mains for supplying water to other utilities.
  • Automatic notifications to management and operations staff can provide time to shut down power and chemical systems at the water treatment plant, therefore improving recovery times, and evacuate unsafe areas. In addition, power to facilities can be cut to prevent fires and allow safe operator egress from areas that may be damaged or chemically contaminated. 
  • Protection of this equipment could save in the range of hundreds of thousands of dollars. Though difficult to predict, cost savings due to reduced fire risk from shutting down power at facilities could range in the millions of dollars.


Rogue Valley Council of Governments (RVCOG)

  • As a ShakeAlert Facilitation partner, Rogue Valley Council of Government provides communication and technical expertise to local partners on ShakeAlert information and products.  
  • RVCOG’s focus is on post-event recovery for critical infrastructure and staff members of water, sewer, public safety, public health, transit, land use and transportation planning, government staff, and non-profit disaster relief organizations.
  • RVCOG’s engaged partners across Josephine (population: 84,745) and Jackson county (population: 212,567) include all 15 local governments, 8 additional entities (special districts and higher education) and non-member entities of Providence Hospital, Asante Hospital, Pacific Power, Avista, the Oregon Department of Forestry, ACCESS, the Rogue Valley Manor, Data Center West, and Josephine County 911.
  • All entities involved, approximately 2,000 staff are within the influence of RVCOG partner’s ShakeAlert software installs.  When the 911 call centers in both counties have introduced the software installations into their operations, many thousand more can potentially be impacted.

Impact of Washington ShakeAlert Pilot Programs

Coming soon!

A US Geological Survey seismic hazard map for the city of Seattle.

Background: The Challenges of Predicting Seismic Hazard

We all want to know when the next big earthquake will happen. But because we can’t predict earthquakes, the next best thing we can do is figure out how strong shaking could be during future quakes. To do this, earth scientists can reconstruct an area’s historic earthquake record using geologic markers and any available written accounts, which allows them to constrain recurrence and magnitude ranges for quakes on local faults. Scientists then combine these estimates with what we know about an area’s surface geology to predict how often and how strong the ground will shake during an earthquake. This sort of analysis is the basis for the US’ National Seismic Hazard Mapping Project, and it is critical for making sure we build structures that can withstand earthquake shaking.

Predicting how an earthquake will shake an area is not a trivial task, however.  Besides the challenges of figuring out the historical earthquake record from sparse geologic markers, understanding how conditions at a given location will affect earthquake shaking is very difficult. In Seattle, for example, there are many interesting geologic features that change and amplify ground motion during earthquakes; large areas of water-logged, artificial fill under Pioneer Square and SODO have amplified ground motion and even liquefied during historic earthquakes; the deep Seattle Basin, which contains thick layers of relatively soft sediments, traps seismic waves and “sloshes” like a big bowl of jelly in some earthquakes. Taking these effects into consideration during seismic hazard analysis is important, but requires a detailed understanding of the local geology and how it affects seismic waves.


The hills are alive with the sound of … earthquakes?

A geographic component that is not often considered during seismic hazard analysis is topography. As seismic waves from an earthquake propagate through the earth, they interact with subsurface geology, like faults and basins; however, the waves also interact with surface features, like hills, cliffs, and valleys. Depending on the wavelength of the seismic waves and the direction they’re traveling, the shaking felt on these features can be much stronger (or weaker!) than in surrounding flat areas. This amplification happens because these features scatter and trap seismic energy; they can also experience a sort of structural “resonance”, similar to the way buildings and bridges can. Studies of ground motion from the 2009 L’Aquila and 2010 Haiti earthquakes [1, 2] have shown that topography significantly amplified ground motion at certain locations, sometimes shaking twice as strong as surrounding areas!

With these findings in mind, we are interested in seeing how topography might affect earthquake shaking here in Seattle. While the city doesn’t have any particularly tall or prominent ridges, it does have many steep bluffs and cliffs overlooking Elliott Bay and Puget Sound. We know from past earthquakes that these features are prone to land-sliding, and we would like to know how topographic amplification might contribute to that hazard, as well as to the general safety of structures built on the bluffs.


How will the 70-90m tall bluffs around the city behave in an earthquake?


If you live inside the blue box, please consider hosting a station!

How will things shake out in West Seattle?

So, as part of a graduate-student-led research project, we are looking for volunteers in West Seattle to host seismometers for a small experiment. In this project, portable seismometers will be placed along and down the bluffs facing Puget Sound. Over the course of a few hours, these seismometers will record the ambient vibrations caused by ocean waves, weather systems, and even car traffic. Together, these sources create what’s known as ambient seismic noise. By comparing recordings of this noise from points along the bluff, we can understand how the topography amplifies ground shaking during earthquakes.

For our experiment, we are looking for hosts in West Seattle living near the bluffs along Alki. Ideally, hosts would live on or between Sunset Ave. SW and Alki Ave. SW. We also need a few sites in the neighborhood away from the sea bluff (see the map below). The experiment itself will last just 1 day, and only requires access to your yard, where we will plop-down a coffee-can sized seismometer for a few hours. The experiment will take place some time between early October and late November.

So, if you are a citizen scientist who would like to help us better understand how earthquakes rattle the hills around our city, and you live on or near the Sound-facing bluffs in West Seattle, please consider filling out the form linked below!

If you have any questions about the experiment, you can contact the project lead Ian Stone at

Link to Sign-up Form:


[1] Massa, M., Lovati, S., D’Alema, E., Ferretti, G., and M. Bakavoli, 2010. An experimental approach for estimating seismic amplification effects at the top of a ridge, and the implication for ground-motion predictions: The case of Narni, Central Italy. Bul. Seis. Soc. Amer., 100 (6) 3020-3034.

[2] Hough, S. E., Altidor, J. R., Anglade, D., Given, D., Janvier, M. G., Maharrey, J. Z., Meremonte, M., Mildor, B. S. L., Prepetit, C., and A. Yong, 2010. Localized damage caused by topographic amplification during the 2010 M 7.0 Haiti earthquake. Nature Geoscience, 3. 778-782.