Open AccessSimulation of earthquake sequences *
Author(s) -
Chen Y. T.,
Knopoff L.
Publication year - 1987
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1987.tb01665.x
Subject(s) - aftershock , foreshock , seismology , geology , creep , earthquake swarm , interplate earthquake , slow earthquake , remotely triggered earthquakes , viscoelasticity , earthquake simulation , intraplate earthquake , seismic gap , slip (aerodynamics) , earthquake prediction , induced seismicity , tectonics , materials science , engineering , aerospace engineering , composite material
An earthquake sequence can be considered to be a complex extension of a shear crack in a viscoelastic medium under the influence of non‐uniform stresses. Because of these inhomogeneous stresses, the crack grows rapidly at rates comparable to seismic body‐wave velocities during some intervals of time; during other intervals, which punctuate the episodes of rapid expansion, the major mode of slip and growth is one of creep. Under suitable pre‐stress and frictional conditions, the post‐seismic creep phase of one earthquake may become the pre‐seismic creep phase of a succeeding earthquake. Thus inhomogeneity of the pre‐stress and/or the static and dynamic frictional stresses combined with viscoelasticity of the medium provides a mechanism that accounts for not only the pre‐seismic and the post‐seismic creep and the stopping of the crack, but also the various types of earthquake sequences that occur in nature. By increasing the amplitude of the fluctuations in the spatial distribution of these stresses, the type of earthquake sequence can be varied progressively from an ‘isolated earthquake', to a sequence with foreshocks, main shock and aftershocks, and finally, to an earthquake swarm. As the wavelengths of the fluctuations in the stresses decrease, the frequency of earthquake occurrence increases. The type of earthquake sequence is also controlled by the general level of the stresses. A silent earthquake or aseismic creep event will occur if the pre‐stress is sufficiently high.