Central Oregon Locked Zone Array
Historically, the subducting Juan de Fuca plate has produced very large thrust earthquakes along the Cascadia subduction zone. These events occur every few hundred years on average, with very little documented seismic activity in the interim. Since 2003, about 40 earthquakes have been detected in the nominally "locked" zone offshore central Oregon. Analysis of the two largest earthquakes suggests that they were low angle thrust events on the plate boundary. We are currently operating an onshore/offshore seismic array (COLZA – Central Oregon Locked Zone Array) to better constrain microseismic activity in this region.
The COLZA experiment consists of six temporary land seismic stations from the FlexArray, part of EarthScope's USArray network of instuments, and two deployments of ocean bottom seismometers. Our data are collected and archived with the help of the Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL) and archived by the Incorporated Research Institutions for Seismology (IRIS).
Map of COLZA stations
Recent Earthquake recorded by COLZA
Related Links:
More information on EarthScope (http://www.earthscope.org/)
Land Station Meta-data from IRIS: (http://www.iris.edu/mda/XA?timewindow=2008-2009)
PUBLICATIONS:
Tréhu, A.M., J. Braunmiller, J. L. Nabelek, Probable low-angle thrust earthquakes on the Juan de Fuca–North America plate boundary, Geology, Volume 36, Issue 2 (February 2008) pp. 127–130
Ocean bottom seismometers aboard the R/V Wecoma
Sciences, Oregon State University
104 Ocean. Admin. Bldg.
Corvallis, OR 97331-5503
www.coas.oregonstate.edu
Seismology Homepage
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