Tuesday, November 01, 2011

Locating the Tohoku-Oki Mw9.0 earthquake with Compressive Sensing

Peter Gerstoft sent me the following:

Your blog is very interesting to read. Maybe, you would find the following paper interesting
http://www.agu.org/pubs/crossref/2011/2011GL049223.shtmlGEOPHYSICAL RESEARCH LETTERS, VOL. 38, L20310, 5 PP., 2011, doi:10.1029/2011GL049223
Compressive sensing of the Tohoku-Oki Mw 9.0 earthquake: Frequency-dependent rupture modes, Huajian Yao, Peter Gerstoft, Peter M. Shearer, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA
Christoph Mecklenbräuker
Institute of Telecommunications, Vienna University of Technology, Vienna, Austria

Compressive sensing (CS) is a technique for finding sparse signal representations to underdetermined linear measurement  equations . We  use  CS  to  locate  seismic sources during the rupture of the 2011 Tohoku-Oki Mw9.0 earthquake in Japan from teleseismic P waves recorded by an array of stations in the United States. The seismic sources  are  located  by minimizing  the l_2 norm of  the difference between the observed and modeled waveforms penalized by the l_1 norm of the seismic source vector. The resulting minimization problem  is convex and can be solved efficiently. Our results show clear frequency-dependent rupture modes with high frequency  energy radiation dominant  in the down dip  region  and  low frequency  radiation  in  the  up dip  region , which may because  d  by  differences  in  rupture  behavior  ( more intermittent or continuous) at the slab interface due to heterogeneous frictional properties

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