Earthquakes risk in Washington

Earthquake risk in Washington: what makes it unique

Washington is one of the most earthquake-prone states in the country. The state sits along the Cascadia subduction zone, where the Juan de Fuca plate dives beneath the North American plate, and it also contains dozens of shallow crustal faults—including the Seattle and Tacoma faults—and deep intraslab faults. These sources can produce everything from frequent small quakes to rare but massive megathrust earthquakes. According to the USGS Earthquake Hazards Program, the Puget Sound region, the Olympic Peninsula, and the Pacific coast face the highest shaking potential.

Earthquakes in Washington can happen at any time of year; they are not seasonal. The most exposed areas include:

• Western Washington, especially the Puget Sound lowlands (Seattle, Tacoma, Everett, Olympia) and the coast, where soft soils and fill can amplify shaking.
• Coastal communities, which also face tsunami risk from a Cascadia megathrust earthquake.
• Eastern Washington, which experiences fewer quakes but still has active faults and can feel strong shaking from large events.

The Washington Emergency Management Division notes that a major earthquake could cause widespread damage, disrupt utilities, and isolate communities. Because the Pacific Northwest has a long geologic record of great earthquakes, preparedness is essential.

How it affects homes

Most earthquake damage to homes comes from ground shaking. Common effects include cracked foundations, broken windows, collapsed chimneys, and walls that pull away from the roof. Unsecured water heaters and gas appliances can topple, causing fires or gas leaks. In areas with loose, water-saturated soils, liquefaction can cause homes to sink or shift. Landslides can also damage or destroy homes on steep slopes. Older homes—especially unreinforced masonry or those not bolted to their foundations—are at greatest risk.

Standard homeowners insurance policies typically do not cover earthquake damage. You usually need a separate earthquake policy or an endorsement, which carries its own deductible (often a percentage of the home's value). FEMA and the Washington Emergency Management Division recommend reviewing your coverage and considering earthquake insurance, especially if you live in a high-risk area. Federal disaster assistance may be available after a major quake, but it is not a substitute for insurance and often comes as loans, not grants.

How to prepare your home

Taking steps now can reduce damage and keep you safer. Use this checklist:

1. Retrofit your foundation: Have a licensed contractor bolt your house to its foundation and brace cripple walls with plywood. This is one of the most effective ways to prevent a home from sliding off its foundation.
2. Secure your water heater: Strap it to wall studs with metal strapping and install flexible gas connectors. An unsecured water heater can break gas lines and start a fire.
3. Anchor large furniture and appliances: Use brackets, straps, or museum putty to secure bookcases, TVs, and refrigerators. Keep heavy items on lower shelves.
4. Install an automatic gas shut-off valve: This device stops gas flow when it senses strong shaking, reducing fire risk.
5. Check your chimney: Have it inspected and reinforced; unreinforced brick chimneys are a common source of damage and injury.
6. Create a emergency kit and plan: Follow Ready.gov guidance for a kit with water, food, medications, and a battery-powered radio. Practice Drop, Cover, and Hold On with your household.
7. Know how to shut off utilities: Learn where your gas and water shut-off valves are and how to use them—only if you suspect a leak.

These measures can also lower your insurance premiums in some cases. For more detailed guidance, see FEMA's earthquake safety resources.

Frequently asked questions

How often do earthquakes occur in Washington?

Small earthquakes happen frequently—Washington experiences thousands of tiny quakes each year, though most are not felt. Damaging earthquakes occur less often, but the state has a history of large events, including the 2001 Nisqually earthquake (magnitude 6.8) and prehistoric megathrust quakes on the Cascadia subduction zone. The USGS provides current data and hazard maps.

Does my homeowners insurance cover earthquake damage?

Generally, no. Standard homeowners policies exclude earthquake damage. You need a separate earthquake policy or an endorsement. Deductibles are often 10–20% of your home's insured value, so review costs carefully. The Washington Emergency Management Division offers consumer tips for earthquake insurance.

What should I do during an earthquake?

If you are inside, Drop, Cover, and Hold On: get under a sturdy table or desk, protect your head and neck, and hold on until shaking stops. If you are outside, move away from buildings, streetlights, and utility wires, then crouch low. If you are driving, pull over to a clear spot and stay in your vehicle. Ready.gov has detailed guidance for different situations.

Official resources

• Washington Emergency Management Division
• USGS Earthquake Hazards Program
• Ready.gov – Earthquakes
• FEMA Earthquake Safety