First in a Series-Disaster Preparedness

Posted by Gary O'Rielly 
on Aug 13, 2013
 
Our guest last week was Bill Steele from the Pacific Northwest Seismograph Network and the FIRST IN A SERIES ON DISASTER PREPAREDNESS. Are we prepared for a disaster? Steele is part of a network working on an Earthquake Early Warning System- an early ground motion warning system which will allow people to get ready for an earthquake minutes before it hits and not just seconds.
 

A short documentary by Mahesh Punyamurthula showing the ability to predict P Waves and S Waves showing the onslaught of an earthquake. Lives can be saved even if we have only seconds or minutes advanced warning about the earthquake. Major disasters and perhaps death could be avoided if these programs are in place.

Earthquake centers in Seattle, Berkeley and Pasadena are working in cooperation with USGS. The system would cost about $100 million to install with an annual cost of $10 million. There are three kinds of earthquakes in the Cascadia zone. Seattle fault has the best record of information and the Juan de Fuca plate has a shadow zone. Gravity measurements reveal deep structure where basins trap seismic energy. Long period resonance match CS2 ground motions. There are two of faults along the Western US--the Cascading subduction and the San Andreas strike slip and a subduction plate boundary.

How often does Cascadia break with a 500 year recurrence for M9 ruptures? Steele showed a chart listing the last 10,000 years of big earthquakes from offshore geology. The big earthquakes and their hazards are more of a strain on Oregon. On about 14% chance of an M9. Shallow Seattle Fault M 6.5 chances is about 5%. In 2001 there was a 6.8 magnitude earthquake.

The last part of the presentation was a video showing an early earning system in Japan during a Japanese Parliament session. Great program with a really great presenter. Several questions followed the conclusion of the meeting while Bill Steele stayed around to answer everyone's questions.