Learning from dynamic triggering of low-frequency tremor in subduction zones
© The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences. 2008
Received: 19 August 2008
Accepted: 9 October 2008
Published: 24 October 2008
Remote triggering of small low-frequency seismic tremor (non-volcanic tremor) near the seismic-aseismic transition zone of subduction zones, by surface waves from large distant earthquakes, has been reported in southwest Japan and the Cascadia region. Recent observed triggering in southwest Japan from three large earthquakes (2003 Tokachi-oki, 2007 Solomon, and 2008 Wenchuan) covering wide azimuthal information provides strong evidence for the influence of fluids in the source area. The Coulomb failure stress analyses suggest the effective friction coefficient is large for southwest Japan and small for the Cascadia region, which could be related to the amount of fluid in the source regions of the low-frequency tremor.