Seismo Blog

Take a look around the room you are in: see any large pieces of furniture? Wall hangings? Heavy light fixtures? Is your computer monitor strapped down? During the 1989 Loma Prieta earthquake in California, 95 percent of the injuries were caused by people falling or being struck by loose objects. During this year’s Great ShakeOut, we at PNSN will also take a look at the non-structural hazards that surround us.

This Thursday, 50 million people will drop, cover, and hold on for the 8th Annual Great ShakeOut, the largest earthquake drill in the world.  This year at the PNSN, our motto is “drop, cover, hold on, and do something else too”. We are thinking about other ways that we can enhance our preparedness for a major earthquake. On the SeismoBlog this week, we are outlining a few other strategies to supplement this year’s drill.

The Great ShakeOut gives people a chance to practice the recommended “drop, cover, and hold on” protocol, which involves getting on the ground, taking cover under a table or desk, and holding on until the earthquake is over. That protocol is based on decades of research into how individuals and organizations can best protect themselves during strong earthquake shaking.

On Thursday shortly after our drill on the University of Washington campus, we at the PNSN will do a “hazards hunt” to identify and remedy some non-structural hazards in our lab. From lab equipment, to coffee mugs, to some big, heavy textbooks, we’ve already noticed a few unsecured building contents that could be dangerous and diminish our ability to get back to work in the aftermath of a major earthquake. Luckily, there are many simple and inexpensive fixes that can help keep us safe and reduce our losses—all of them applicable to your home or business, as well.

Here are a few non-structural hazards we’ve already noticed and some potential fixes*:

Computer monitors: Electronics, like computer monitors, are heavy and costly to replace. You can secure your computer monitors and other electronics using nylon straps or buckles. It’s a cheap fix that will help you secure expensive equipment, protect your data, and prevent a falling hazard.

Falling objects: Objects on high shelves (like this giant globe) can become deadly projectiles during an earthquake. You can use earthquake putty (museum wax) to secure your delicate collectibles from falling, breaking, or hurting you during an earthquake. Heavy objects and other breakables can also be moved to lower shelves.

Kitchen: During an earthquake, unsecured cabinet doors are likely to fly open, allowing your cups, plates, and other glassware to fall to the floor. There are a number of latches that will keep your cabinets closed and protect you from broken glass during an earthquake.

Here are some other common hazards you might notice in your home or at your organization:

Water heater: Take a look at your water heater. Is it properly braced to the wall? If it falls over during an earthquake, it can smash your gas line and trigger a gas leak or fire, or smash your water line and start a flood. You can hire a plumber to secure your water heater or do it yourself with this kit.

Wall hangings: During an earthquake, mirrors, picture frames, and other hanging objects can bounce off the walls. Secure them with closed hooks or with screw hooks fastened directly into wall studs.

Here are a few  other resources that will walk you though identifying and correcting non-structural hazards to prepare:

If you hazard hunt with us this Thursday, tag us in a tweet (@pnsn1) and use the hashtag #hazardhunt


*hyperlinked products are examples, not recommendations

 

Cascade Volcano Seismology - a Tutorial

October 5, 2016

by Steve Malone

A newly modified tab on each volcano page gives a nice overview of each's earthquake history. Here is an introduction and some hints for interpreting these plots.

iMUSH: Adventures in the Field

September 12, 2016

by Lauren Burch

Seismology graduate student Mika Thompson shares a thrilling tale of wasps, fallen trees, and other impediments to science.

The Long Trek to MH09

September 8, 2016

by Shelley Chestler

Sometimes uninstalling a seismic monitoring station doesn't go quite as planned. Here is tale of my team's first attempt to take out a particularly stubborn station for the iMUSH (Imaging Magma Beneath St. Helens) project:
Both the Cascade Mountains and the Olympic Mountains are products of subduction, but not all mountain ranges are created in the same way.

Another debris flow avalanche at Mount Baker

June 15, 2016

by Steve Malone

Seismic signals on May 25 are evidence for the size and timing of yet another on of these avalanches.

All the mountains, oceans, and islands on Earth exist because of plate tectonics. Different plate boundaries produce different geologic features: divergent boundaries spread apart to form mid-ocean ridges and rift valleys, transform boundaries slide past one another to form strike-slip faults like the San Andreas, and convergent boundaries collide to form tall mountains, deep trenches, and volcanoes. This type of plate boundary is responsible for the numerous volcanic arcs around the Pacific Rim (often called the “Ring of Fire”), and formed our iconic Cascade Volcanoes. Here in the Pacific Northwest, the Juan de Fuca plate is subducting beneath the North American plate along a convergent plate boundary called the Cascadia Subduction Zone (CSZ). Subduction zones like this are the only fault systems capable of producing very large megathrust earthquakes, but they only do so occasionally - over the last 100 years, there have been 84 earthquakes of magnitude 8.0 or greater worldwide, and only 4 of them were greater than an M9.

 


The simplest answer to the question “Will there be another large earthquake on the CSZ?” is yes. However, the question of “when” is much more difficult to answer. Seismologists don’t know exactly when the next large earthquake will occur on the CSZ, but we do have a good picture of when they have happened over the past 10,000 years. If we divide 10,000 years by the number of ~M9 earthquakes found in that time period, the average recurrence rate for M9 earthquakes along the CSZ is roughly 550 years. We are 316 years past the last great CSZ earthquake in 1700, and we estimate that there is about a 15 % chance that an M9 will occur on this fault within the next 50 years. However, research on submarine landslide deposits shaken loose by big earthquakes indicate that M8+ earthquakes occasionally strike off the coast of Oregon in between “full rip” M9 events. This research suggests that there is a greater probability of reoccurence of a great earthquake in Southern Oregon than off the Washington coast, but there is not a consensus within the geophysical community as to specifically how much greater the hazard is.

One is a guess, and the other is an educated guess.
Earthquakes happen on faults, but where are the faults in Oregon and Washington? The new "Display Faults" tool on the PNSN Recent Events map can help you explore the locations of faults in the Pacific Northwest.

Exotic Events (not erotic events)

April 1, 2016

by Steve Malone

Seismically recorded non-earthquakes now have their own page at the PNSN.

Negative depth earthquakes?

March 30, 2016

by Steve Malone

Why do some earthquakes in our list have negative depths now?

Explosion "Earthquakes"

March 10, 2016

by Steve Malone

Two recent large explosions generated acoustic waves recorded on seismographs.

West Coast Earthquake Early Warning System on the Horizon

February 9, 2016

by Shelley Chestler

Last week the White House hosted 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.

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......