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The Long Recurrence Intervals of Small Repeating Earthquakes May Be Due to the Slow Slip Rates of Small Fault Strands
Author(s) -
Williams J. R.,
Hawthorne J. C.,
Lengliné O.
Publication year - 2019
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 - 10.1029/2019gl084778
Subject(s) - slip (aerodynamics) , scaling , seismology , geology , seismic moment , san andreas fault , fault (geology) , geometry , physics , mathematics , thermodynamics
Observations since 1998 have revealed that repeating earthquakes, and particularly small repeating earthquakes, occur less often than expected given their seismically derived slip and the regional fault slip rate. Here we test the hypothesis that small repeaters occur infrequently because they occur on fault segments or strands with low slip rates. We analyze the recurrence interval‐moment scaling of earthquake sequences near Parkfield, California. We find that closely spaced sequences, which likely occur on the same fault strand and respond to the same slip rate, follow aM 01 3scaling consistent with seismic slip rates while widely spaced sequences, which likely occur on different strands, follow aM 0 0 . 17scaling consistent with the previous counterintuitive observations. These results suggest that spatially varying slip rates could create theM 0 0 . 17recurrence interval scaling, though we cannot exclude other explanations.