Recent Earthquakes

Recent natural and manmade seismic activity.  Click figure for details.

 Quakes Near Volcanoes

Seismicity in Last 30 Days

Volcano Earthquakes
St. Helens
30 Days Ago Now

Volcanoes without recent seismicity

Adams, Baker, Crater Lake, Glacier Peak, Jefferson

10 seconds of early warning for last weeks California earthquake

Posted by S. Malone, 09/01/2014

The Contra Costa Times and the Los Angeles Times have brief articles on the success of the California earthquake early warning system for last week's Mag=6 Napa Valley event.

Mag 6.0 Earthquake in California this morning

Posted by S. Malone, 08/24/2014

The Seattle Times has a lengthy story on the M=6.0 earthquake in the Napa Valley area of northern California this morning. There is a good scientific tectonic summary by the US Geologic Survey.

Some controversy in Earthquake Early Warning

Posted by S. Malone, 08/14/2014

MarketPlace news has a report on the "controversy" between a private version of EEW and the US Geological Survey sponsored version (in which the PNSN is participating).  While there are some mistakes in this report it does summarize some important issues: a cheap, semi-secret, private EEW versus a more expensive, open-information, public EEW.

How frequent is there a Cascadia mega-earthquake?

Posted by S. Malone, 08/10/2014

The Seattle Times has a very good discussion of the different interpretations of deep-sea geologic evidence for the frequency and size of our big earthquakes.  There is no question that they occur, just what some of the evidence for their frequency means.  A more garbled view of the controversy was in the science journal, Nature, last week.

Latest Seismo Blog Posts

Three Cascadia ETS events in past month??

September 4, 2014

by Steve Malone

Since Aug 10 there have been three parts of the Cascadia subduction zone with extended periods of near continuous tectonic tremor. Typically if tremor continues in a zone for more than 10 days then the geodesists can easily see an accompanying slow-slip event coincident with it. While tremor in the three zones has not been exactly synchronous it is somewhat unusual for this much of Cascadia to "light up" this strongly all together. For some of the details....

Is Mount St. Helens seismicity increasing?

July 29, 2014

by Steve Malone

Looking at the "Quakes near volcanoes" plot today shows that 87 earthquakes have been recorded at Mount St. Helens over the past 30 days. This is way above the average for the past many years. Is this significant? Actually, no. Its called a sampling artifact that gives the impression of increased activity. For the details......

The PNSN reduces risk within the states of Washington and Oregon by

  • monitoring ground motions within the region in order to better understand earthquake and volcano hazards and their impacts on the physical, economic, political, and social environment,
  • providing the most accurate information about earthquakes and volcanoes as rapidly as possible to public officials, the public, and for education, and
  • advocating comprehensive and cost-effective measures for reducing the harmful effects of earthquakes and volcanoes.