Seismo Blog

West Coast Earthquake Early Warning System on the Horizon

February 9, 2016

by Shelley Chestler

The New Yorker article, “The Really Big One,” did more than inform people around the country of the threat of the large, impending earthquake that will happen off the coast of Oregon and Washington.  It brought Pacific Northwest earthquake hazards to the attention of the White House.  On Tuesday, February 2, President Obama’s Science Adviser, John Holdren, invited earthquake scientists and other stakeholders to the first ever Earthquake Resilience Summit. One of the main goals of the meeting was to discuss the potential for fully funding a west coast earthquake early warning system. 

The idea of earthquake early warning is not new.  Japan’s earthquake early warning system launched in 2007 and provided alerts during the 2011 M9.0 earthquake off the coast of Tohoku. The United States Geological Survey has been working on a west coast early warning system since 2006.  The system, ShakeAlert, began sending test alerts to selected California users in 2012.   The goal is for ShakeAlert to be developed into a system that will provide earthquake warnings to companies and residents along the entire west coast.  One of the main obstacles to the implementation of the system is that it costs money.  The estimated cost of upkeep is ~$16 million per year.

What exactly is an earthquake early warning?  It is not an earthquake prediction—a warning can only be issued once an earthquake has already started.  An earthquake produces two types of seismic waves that travel through the earth.  The less damaging P waves, which compress the earth like an accordion, arrive at earthquake sensors, or seismometers, first.  After four seismometers pick up the P waves, the system registers that an earthquake occurred and issues an alert that the more damaging S waves are coming.  Depending on your distance from the earthquake’s starting location, you could get anywhere from a few seconds to five minutes of warning.

To get alerts out as quickly as possible the earthquake early warning system needs two things: a wide distribution of seismometers and short data processing times.  With a wide distribution of evenly spaced sensors, there will be a higher chance that four seismometers will be close to any earthquake source.  In addition, it takes time for data to be collected by the sensor, transmitted to the computer at the PNSN, and processed.  For faster alerts, we want to minimize this time, or system latency.  

The figure below shows the warning times (for an ideal network) that Seattle (left) and Portland (right) would get for any earthquake at 15 km depth.  To find the warning time of an earthquake, look at the contour line closest to the earthquake’s location. For example, if an earthquake occurred at the location of the yellow star (map view location of the 2011 Nisqually earthquake) Seattle and Portland would get 10 and 40 seconds of warning respectively.  The red triangles indicate the locations of current PNSN seismometers.

To create the ideal network configuration used to calculate the times in the above figure, we need to both improve and maintain the current network of earthquake sensors.  This will require additional funding.  Luckily, after the Earthquake Resilience Summit, the White House, state and local governments, and many private stakeholders have committed both time and money to improving earthquake preparedness.  This includes a $3.6 million grant from the Gordon and Betty Moore Foundation to advance the ShakeAlert system and additional pledges from many Pacific Northwest businesses.

What could you do with 10 seconds of warning? Though it doesn’t seem like much, 10 seconds is enough to drop, cover, and hold, pull over your car, or turn off your stove. Other benefits of a warning system are numerous; doctors could stop operating on patients, businesses could stop critical operations, and transit systems such as the BART in San Francisco could break their trains.  So, stay alert.  With increased funding, the implementation of a west coast earthquake early warning system is on the horizon.

Back-to-back ETS events, maybe

February 6, 2016

by Steve Malone

Following the recent "standard" northern Washington ETS another has apparently started heading south toward Oregon.

Slow Earthquake Trembles beneath Vancouver Island

January 7, 2016

by Shelley Chestler

Did you know that there is a type of earthquake that happens so slowly that we can’t feel it? One of these slow earthquakes is happening under Vancouver Island and northern Washington right now!

A Perspective on Tremor Activity

January 7, 2016

by Aaron Wech

With tremor activity occurring in the Pacific Northwest, it's important to provide perspective.

Don't Sweat the Little Ones

December 14, 2015

by Shelley Chestler

The recent earthquakes around the Puget Sound are probably not indicative of the “big one.”

A new look for pnsn.org

December 4, 2015

by Jon Connolly

The new pnsn.org website aims to provide a better user experience for all devices, prioritize features, and provide robust availability during a seismic event.
The July 2015 New Yorker article “The Really Big One,” by Kathryn Schulz, shook up the Pacific Northwest (PNW) more than any earthquake has since the Magnitude-6.8 Nisqually earthquake in 2001. In the article’s most dooming statement, the head of the Cascadia FEMA division was quoted saying, “everything west of I-5 will be toast.” This assertion scared the living daylights out of PNW residents, creating a sense of terror and hopelessness that was the antithesis of what the article meant to do: to spur the region into preparing for this potentially devastating event.

Unusual earthquake swarm south of Bend, OR

October 23, 2015

by Steve Malone

A somewhat unusual earthquake swarm started early on Oct 22, 2015 in an area about 65 km (40 miles) southwest of Bend, OR (25 km WSW of La Pine, OR). 36 events have been detected and located by the PNSN as of noon on Oct. 23, the largest only Magnitude 2.5. This ongoing swarm is in the same area that had similar swarms in 2001 and 2012 and is likely just the same sort of thing taking place again. For more details and updates....

How big was that earthquake?

September 24, 2015

by Steve Malone

Determining an earthquake's size seems to often result in different and inconsistent estimates. The "Magnitude" of an earthquake can be determined by several different methods, all of which should have some relationship to one another and, at least be consistent one earthquake to another. Unfortunately that's often not the case. PNSN seismologists spend lots of time estimating (measuring and calculating) earthquake magnitudes and end up discussing (arguing over) different techniques and complaining (whining) about inconsistencies and criticizing (belittling) certain results. Recently some effort is being made to try and refine (improve) our standard, routine ways of determining magnitude. We are starting to upgrade our published catalog with these "improved" magnitude estimates so you may see these estimates change from what was in the catalog before. Don't worry. The earthquakes have not changed, just our estimate of how big they are. For the gory details of how this is being done......

Summer rockfall time, yet again

August 21, 2015

by Steve Malone

With hot dry weather it is not surprising that the seismic records for volcano stations show lots of signals consistent with rockfall/avalanches and other exotic seismic events. In fact it is a bit of a surprise that we have not seen more and bigger such events this summer........ so far. Recent activity at Mount Rainier has included a debris flow (probably related to a jökulhlaup) and a moderate sized rockfall from high on the southwest side of the volcano. For some of the seismic details.....

Why earthquakes disappear

May 31, 2015

by Renate Hartog

Earthquakes have been appearing and disappearing from the U.S.G.S. webpages, this blog explains why.

PNW Earthquake Early Warning prototype goes live

February 18, 2015

by Steve Malone

Earthquake Early Warning (EEW) is now officially working for the Pacific Northwest (Washington and Oregon) in the same way it has in California for the past two years. It even got tested the first night in operations and worked...sort of. A workshop hosted by the PNSN at the University of Washington on Feb 17 introduced the topic and featured software to a group of about forty invited participants. For a few details on the workshop and the system's first live test......
The Seattle Seahawks' win over the Green Bay Packers in over time ended up so exciting that many of us serious scientists forgot to be serious and analyze the seismograms. Yikes! What a crazy ending. In fact, most of the game was seismically quiet (and disheartening for Seahawk fans), but the final half hour produced several seismic events that challenges the original "Beast Quake" for seismic supremacy. For our semi-scientific analysis......

Panther versus Seahawk Game Analysis

January 11, 2015

by Steve Malone

Both the PNSN experiment and the Seahawks were successful Saturday evening. Both got off to a slow start. The PNSN QuickShake display had several bad dropouts during the first half and at half-time the Seahawks were only ahead by four points. When working properly QuickShake provided us with "early Warning" of a successful play that would show up on TV a few seconds later. None of the signals compared to the size of those during the original "Beast Quake" of 2011 but some interesting patterns were seen. For more detailed analysis......
Last year the PNSN used the vibrations generated by enthusiastic Seahawk fans at CenturyLink Field to test instruments, data acquisition and web based displays. Some might say the seismic monitoring inspired fans to greater cheering resulting in the Seahawk's successful Super Bowl run. With new instruments recently acquired and improved data processing and display techniques developed we are again looking for somewhere to test them. With the Seahawks again in the playoffs with home field advantage why not watch/help them again? For the details.....

Canadian ETS morphing to Washington one?

November 18, 2014

by Steve Malone

Over two weeks of tremor in central Vancouver Island has been progressing southward. Though we don't know about the geodetic component we suspect that this represents a slip event that is propagating southward. Since a southern Vancouver Island-Northern Puget Sound ETS is due about now the question is will this current activity continue all the way to southern Puget Sound. For some details.....

Great ShakeOut, Great success!

October 16, 2014

by Angel Ling

Congratulations and thank you for your participation in the Great ShakeOut Earthquake Drill! Hopefully it gave you a great opportunity to practice "Drop, Cover and Hold on", and review and update emergency preparedness plans and kits/supplies. Thanks again to make the Pacific Northwest safer. Read more to see what the Great Washington ShakeOut looks like at the PNSN!

The Great ShakeOut 2014 is Tomorrow!

October 15, 2014

by Angel Ling

Tomorrow is the Great Washington Shake Out 2014! Please join us in the World's largest Earthquake Drill at 10:16 a.m. on October 16. Read more...

Three Cascadia ETS events in past month??

September 4, 2014

by Steve Malone

Since Aug 10 there have been three parts of the Cascadia subduction zone with extended periods of near continuous tectonic tremor. Typically if tremor continues in a zone for more than 10 days then the geodesists can easily see an accompanying slow-slip event coincident with it. While tremor in the three zones has not been exactly synchronous it is somewhat unusual for this much of Cascadia to "light up" this strongly all together. For some of the details....

Is Mount St. Helens seismicity increasing?

July 29, 2014

by Steve Malone

Looking at the "Quakes near volcanoes" plot today shows that 87 earthquakes have been recorded at Mount St. Helens over the past 30 days. This is way above the average for the past many years. Is this significant? Actually, no. Its called a sampling artifact that gives the impression of increased activity. For the details......
Several days of very warm weather has resulted in a couple of large snow avalanches at Mount St Helens but apparently no unusually large ones at other volcanoes. The seismic network at Mount St. Helens is particularly good at picking up the shaking due to large snow avalanches. Two such events on the afternoon of May 14 got our attention. For copies of seismograms and photos......
A large explosion was reported in the early morning hours of April 25 in North Bend, WA. I reviewing the seismic records we find signals consistent with this report. For a preliminary report.....
PNSN instruments picked up the ground vibrations generated by the deadly Oso landslide.

Legacy web site content returns

March 17, 2014

by Steve Malone

Two years ago the PNSN web site changed format in a big way. New features and capabilities were added and the look and feel was greatly improved. But, many of the old popular pages were left behind. We have now converted many of these pages to generic documents that can be linked from the new pages but are still in the old format. For a summary of what we have now....

Ice avalanches on Cascade volcanoes

February 28, 2014

by Steve Malone

With the recent heavy snows in the mountains after a long, cold dry spell the Cascades could be primed for big snow avalanches. However, just in the past couple of days we have seen two big seismic sources that we interpret to be, at least initiated as ice avalanches at Mount Rainier and Glacier Peak. For some details and photos...... (and an update)