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Influences on the location of repeating earthquakes determined from a and b value imaging
Author(s) -
Kawamura Masashi,
Chen Kate Huihsuan
Publication year - 2017
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 - 10.1002/2017gl073335
Subject(s) - seismology , induced seismicity , geology , thrust fault , slip (aerodynamics) , fault (geology) , seismic gap , san andreas fault , geodesy , physics , thermodynamics
To explore where earthquakes tend to recur, we statistically investigated repeating earthquake catalogs and background seismicity from different regions (Parkfield, Hayward, Calaveras, and Chihshang Faults). We show that the location of repeating earthquakes can be mapped using the spatial distribution of the seismic a and b values obtained from the background seismicity. Molchan's error diagram statistically confirmed that repeating earthquakes occur within areas with high a values (2.8–3.8) and high b values (0.9–1.1) on both strike‐slip and thrust fault segments. However, no significant association held true for fault segments with more complicated geometry or for wider areas with a complex fault network. The productivity of small earthquakes responsible for high a and b values may thus be the most important factor controlling the location of repeating earthquakes. We inferred that the location of high creep rate in planar/listric fault structures might be indicated by a values of ~3 and b values of ~1.