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The spatial density of foreshocks
Author(s) -
Brodsky Emily E.
Publication year - 2011
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 - 10.1029/2011gl047253
Subject(s) - foreshock , geology , seismology , geodesy , geophysics , aftershock
Aftershocks follow a well‐defined spatial decay pattern in the intermediate field. Here I investigate the same pattern for foreshocks. Foreshock linear density decays as r −1.5±0.1 over distances r of 0.1–30 km for 15 minutes before magnitude 3–4 mainshocks. This trend is the same as that of the aftershocks within the error of the measurement. This consistency of spatial decay can be explained by the clustering inherent in earthquake interactions. No additional preparatory process beyond earthquake triggering is necessary to explain the spatial decay.