21.6 km  SW of Mount Vernon, WA
    33.4 km  SW of Sedro Woolley, WA
    77.6 km NNW of Seattle, WA

If you would like, you may fill out a form describing how the earthquake affected you. This information will be used to produce an "intensity" map illustrating how shaking and damage from the earthquake varied from place to place.
Yes, I want to fill out the EARTHQUAKE FORM

Detailed Information and Graphics about the Earthquake

Our data base of earthquake hypocenters contains information from the 19th century to the present. Included are:

• A map of the Pacific Northwest showing the location of the earthquake (in red) plus prior earthquakes M > 3.5. Shallow events are black. Events deeper than 35 km are green.
• A map showing a closer view of the earthquake and prior historical earthquakes with magnitude 3.5 or greater. Shallow events are black. Events deeper than 35 km are green.
• A list of 10 big earthquakes preceding the mainshock that are closest to it and have a magnitude greater than 3.5. These are the most significant historical earthquakes in the vicinity of the mainshock (see the closer view map above).
• A map showing the location of the earthquake relative to cities.
• A map showing the location of the earthquake relative to the nearest seismograph stations that recorded it.
• A detailed list of all earthquakes (M > 1.0) that occurred in the vicinity of the special earthquake in the previous two years. For the locations of these events see the next map.
• A map of all earthquakes (M > 1.0) that occurred in the two years prior to the special earthquake. Detailed area shown is just few kilometers around the mainshock.
• A List of the nearest 20 strong motion sites
• Archive of Webicorder displays for this event.

Earthquake Mechanism

If sufficient P-wave first motion data are available, a fault plane determination for the earthquake will be available in the form of

• A diagram of the fault plane solution(s). In some cases more than one solution may fit the data.
• A table describing the fault plane solution(s) summarizing the characteristics of possible fault planes ("A" and "B") that are consistent with the recorded first-motion data.

Moment Tensor Estimates of the Earthquake size may also be available. To see, check at Oregon State U.

• Moment-Tensor Web site at Oregon State University

Preliminary Strong Motion Information

• Strong-motion information from digital accelerographs.

Related Information: Most Up-to-Date Local, National, and Global Earthquake Summaries

• Catalog and Map of Pacific Northwest earthquakes, Mag>2 from the PNSN
• Catalog and Map of United States earthquakes, from the ANSS
• Catalog and Map of world earthquakes, from the IRIS