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Foreshocks and pre‐events associated with the nucleation of large earthquakes
Author(s) -
Shibazaki Bunichiro,
Matsu'ura Mitsuhiro
Publication year - 1995
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/95gl01196
Subject(s) - foreshock , nucleation , asperity (geotechnical engineering) , geology , seismology , slip (aerodynamics) , fault plane , fault (geology) , geophysics , aftershock , geotechnical engineering , physics , thermodynamics
We propose a theoretical model which can explain the occurrence of foreshocks and pre‐events associated with the nucleation of large earthquakes. We consider a broad weak zone with a locally strong part (asperity) on a fault plane in a two‐dimensional framework and examine the transition process from quasistatic nucleation to high‐speed rupture propagation through numerical simulations. The dynamic rupture of the asperity occurs in three different manners, as aseismic slip, foreshock or pre‐event, depending on the peak stress of the asperity. In all cases the rupture of the asperity accelerates the nucleation of main rupture.