论文信息 - Real-time W phase inversion during the 2011 off the Pacific coast of Tohoku Earthquake

Real-time W phase inversion during the 2011 off the Pacific coast of Tohoku Earthquake

The real time W phase source inversion algorithm was independently running at three organizations (USGS, PTWC and IPGS) at the time of the 2011 off the Pacific coast of Tohoku Earthquake. Valuable results for tsunami warning purposes were obtained 20 min after the event origin time. Within the next hour, as more data became available, the W phase solutions improved, and converged to a common result (Mw ≈ 9.0, dip ≈ 14°). A post-mortem W phase analysis using data selection based on pre-event noise confirmed the Mw = 9.0 result and yielded a best double couple given by (strike/dip/rake = 196°/12°/85°). We also ran the algorithm with increasingly longer periods (T ≈ 1500 sec) to test for the possibility of additional slow slip. The seismic moment remained stable, confirming the prior results.

[1] Hiroo Kanamori,et al. W phase source inversion for moderate to large earthquakes (1990–2010) , 2012 .

[2] Hiroo Kanamori,et al. Use of long-period surface waves for rapid determination of earthquake-source parameters , 1981 .

[3] David J. Wald,et al. Advancing techniques to constrain the geometry of the seismic rupture plane on subduction interfaces a priori: Higher‐order functional fits , 2009 .

[4] L. Rivera,et al. Vertical and horizontal seismometric observations of tides , 2006 .

[5] Hiroo Kanamori,et al. Source inversion of W phase: speeding up seismic tsunami warning , 2008 .

[6] David J. Wald,et al. 88 Hours: The U.S. Geological Survey National Earthquake Information Center Response to the 11 March 2011 Mw 9.0 Tohoku Earthquake , 2011 .