Washington State Department of Natural Resources Geology Portal
You search your address for geologic hazards that have been identified. Select the hazards you want to view in the Table of Contents area of the page.
The Cascadia Subduction Zone (CSZ) is a “megathrust” fault 620 mi long off the west coast, stretching from Northern Vancouver Island to Cape Mendocino, California.
On the night of January 26, 1700, a magnitude 9.0 earthquake shook the region, sending a tsunami almost immediately inland along the west coast of the US and arriving roughly 10 hours after the quake as a 16-foot wave on the shores of Honshu Island, Japan.
Seattle & other Local Fault Earthquakes
Landslides
A tsunami originating from a faraway source. Typically distances greater than 600 miles or more than three hours of tsunami travel time from its source.
Examples include Alaska, Japan, and rare events like the underwater volcanic eruption near Tonga.
The impacts of distance-source tsunamis pose the greatest risk along the outer-coast of Washington.
The oral history shared by many coastal Tribes in the Northwest tells the story of the Thunderbird and the Whale and the danger of these waves.
Please note that currently, these Tsunami Signs in the map below are the proposed locations, and any changes to them will be in the same general area and moved to increase visibility. Once the signs are installed, we will update this map to reflect their actual locations.