Automated detection and location of Cascadia tremor

[1] A new autonomous seismic location and detection methodology enables real-time opportunities for high-resolution spatio-temporal monitoring of non-volcanic tremor. Combining a unique cross-correlation technique with epicenter clustering analysis in northern Cascadia automatically yields thousands of tremor epicenters from the May 2008 Episodic Tremor and Slip (ETS) event while routinely detecting and locating inconspicuous inter-ETS tremor bursts. Although ETS events in this area produce about two weeks of continuous tremor, we find a nearly equal amount of tremor during the last 15-month inter-ETS period. The resulting ETS and inter-ETS epicenters occur in the slow slip region where the plate interface is 30–45 km deep and have a sharp, well-resolved updip boundary about 75 km east of the downdip edge of the seismogenic megathrust zone. This ability to track tremor with high spatio-temporal resolution facilitates automatic tremor monitoring and the mapping of the transition zone and regions of locked zone stress accumulation. Citation: Wech, A. G., and K. C. Creager (2008), Automated detection and location of Cascadia tremor, Geophys. Res. Lett., 35, L20302, doi:10.1029/2008GL035458. 1