Wednesday, December 30, 2015

Quake Wake Up in Northwest Washington: Short Update

This woke a few people up in northwest Washington.

From the PNSN site

In Bellingham I felt two shock waves about 4 seconds apart. The first was stronger. Can't say much about the quake at the moment. I am sure the seismic folks will have to get busy figuring it out the motion. The quake was fairly deep - generally a good thing.

Update: The depth of the quake corresponds fairly well with the depth of the subducting San Juan Plate. Shifts and movements in the deep part of subducting plat will cause periodic quakes. This movement was not located along the "stuck" part of the subducting slab. That area is to the west and is shallower.

PNSN has a map of the epicenter on the surface. Keep in mind the epicenter is 50 km down as well. For Victoria the epicenter is further down than it is horizontally - hence the epicenter is over 50 km away from Victoria event though the map shows it as 11 km away. The map also shows where the quake was felt. You can go on line and fill out a form to add to this map It is useful information for how shock waves travel and where they are felt that casts a larger net than seismic stations.

Image from: 

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