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Pre‐seismic changes of noise correlation function (NCF) before the Wenchuan earthquake?
Author(s) -
Peng Hanshu,
Wu Zhongliang,
Jiang Changsheng
Publication year - 2010
Publication title -
concurrency and computation: practice and experience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.309
H-Index - 67
eISSN - 1532-0634
pISSN - 1532-0626
DOI - 10.1002/cpe.1517
Subject(s) - seismology , correlation coefficient , correlation , correlation function (quantum field theory) , geology , negative correlation , waveform , noise (video) , cross correlation , positive correlation , fault (geology) , function (biology) , geodesy , physics , statistics , mathematics , geometry , computer science , medicine , spectral density , quantum mechanics , voltage , artificial intelligence , evolutionary biology , image (mathematics) , biology
We calculated noise correlation function (NCF) around the Longmenshan fault zone which is responsible for the Wenchuan M S 8.0 earthquake on May 12, 2008. We used 58 station pairs in the investigation. The time period considered was from April 21, 12:00 a.m. local time, to May 12, 2008, 12:00 a.m. local time, 22 days before the occurrence of the earthquake. Correlation coefficient between NCF of each day and its previous day (the ‘second cross‐correlation’) was calculated. Four hundred second long waveform is used in the ‘second cross‐correlation’. Before the earthquake, there seemed to be an apparent variation of such correlation coefficient, and such a pattern seemed coherent for almost all the station pairs. From the scattering around the periodical variations of the ‘second cross‐correlation’, a seemingly precursory change can be observed. However, at the present stage, it is still hard to draw any conclusion about the precursory changes before the earthquake. Copyright © 2009 John Wiley & Sons, Ltd.