The Science of ShakeOut! Understanding and Preparing for Earthquakes

October 4, 2024

Kaitlyn Southcott

What is the Great Washington ShakeOut?

The Great ShakeOut is a nationwide earthquake drill that takes place on the third Thursday of October. Each year thousands of organizations and individuals take the opportunity during ShakeOut to practice and update their emergency plans and hold earthquake drills. Most of Washington is prone to earthquakes, and coastal areas have a tsunami risk as well, so it is important to stay aware and prepared.

ShakeOut is also a time to learn about the science behind earthquakes and think about ways to prepare yourself for what to do if you experience an earthquake.

Check out this video from PacSci’s Digital Learning team to learn about earthquake magnitude and how to be prepared: Great Shake Out! (youtube.com)

What causes earthquakes?

Earth consists of layers, from the inner core at the center to the crust on the surface. The earth’s crust is made up of pieces of rock called tectonic plates that fit together like a puzzle to make up the earth’s surface.

These tectonic plates are in constant motion, but these large pieces of land move slowly. Tectonic plates move almost the same speed as your fingernails grow!

A sudden release of pressure or movement along the edge of tectonic plates is what causes earthquakes. These areas are called fault lines, and the movement on fault lines can take many forms.

Tectonic plates can pull away from each other, crash towards another tectonic plate, or slide past another plate. Normally the plates are moving smoothly, but sometimes they get stuck. When they suddenly become unstuck, that’s when earthquakes happen.

To learn more about the movement of tectonic plates, check out this PacSci Now Feature!

The picture below shows recent earthquake activity on the active fault lines in Western Washington. The Pacific plate is moving in one direction, and the Juan de Fuca plate is going in another direction.

These plates pull apart, while the Juan de Fuca plate also slides underneath the North American plate. This area is called a subduction zone and has the risk of a large earthquake.

If you have ever heard people warning about “The Big One”, they are talking about this subduction quake zone.

Source: Washington State Department of Natural Resources

When will the next earthquake happen?

There is currently little to no warning for earthquakes. Earthquakes are unpredictable, so often the only warning you get is when you feel or notice the ground shaking.

While scientists can study geologic history to identify patterns of previous earthquakes in an area, these patterns only tell us the probability of the next earthquake, not when it will occur.

The science of earthquake detection has evolved in recent years that now enables some regions to have up to a few seconds of warning before serious shaking happens.

The ShakeAlert® Early Warning System is an example of one such system for the US West Coast, used by Washington, Oregon, and California. ShakeAlert® works by reading data from sensors placed around earthquake areas and transmitting that data to alert people through their cellphones as an emergency notification. There are over 280 of these sensors across Washington, with research partners at the University of Washington in Seattle.

The ShakeAlert® Early Warning system went live in Washington in 2021. PacSci hosted a virtual event where a panel of experts explained how the system works, how it is informed by both seismology and social science, and how it affects Washington residents.

view the pacsci shakealert event here

For more information on ShakeAlert® and how to sign up for notifications click here!

How can I prepare for earthquakes and other natural disasters?

When you feel shaking, you should immediately Drop to the ground if you’re able, Cover the back of your head and neck with your arms, and Hold On to a sturdy object.

The biggest risk of injury to yourself from an earthquake is from falling objects so it is important to protect yourself during the shaking. Once the shaking stops you should try to exit buildings and spaces and get somewhere safe and away from damage, while still protecting yourself from hazards such as falling debris or downed power lines.

Earthquakes typically have aftershocks, which can be less intense than the main quake, but can still be dangerous. You should be aware of more shaking that can occur minutes to days later after a larger earthquake.

If you are near the coast for an earthquake, be aware of tsunamis too! These are large waves that can sometimes occur after a large quake. You should head away from the coast and towards higher ground right away to be safe from rapidly rising water levels.

Another way to prepare for a natural disaster is to prepare a kit with emergency supplies. You should include items like drinking water, non-perishable food, medications, first aid kit, batteries and chargers, pet supplies, and important documents and identification.

The Washington State Department of Natural Resources has great tips on how to be prepared for earthquakes and other natural disasters here: Emergency Preparedness | WA – DNR.

Source: The Great British Columbia ShakeOut

where can I find more information about earthquakes?

Being curious about the hazards in your area can help keep you and your community safe!

If you would like to continue learning about earthquakes and other geologic features of Washington State, check out these resources:

where can I find earthquake activities?

You can also conduct these earthquake related experiments at home with the following Curiosity at Home projects from PacSci:

Capture the Quake

Make a seismograph to measure your own homemade earthquakes.

Graham Cracker Plate Tectonics

Create plate boundaries and watch what happens to the Earth’s crust the plates move.

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meet the author

Kaitlyn Southcott is a driven health and safety professional working at Pacific Science Center. She takes her previous teaching experience and models curiosity and critical thinking to help maintain a safe environment for staff and guests alike. Kaitlyn is dedicated to collaborating with others to maintain a solution-focused approach. When she isn’t working, you can find her enjoying the great outdoors or the inside of a book.

Pacific Science Center is not affiliated, sponsored, nor partnered with any intellectual property owners or businesses mentioned herein unless otherwise stated.