TY - JOUR
T1 - Slow earthquakes along oceanic fracture zones
T2 - evidence for asthenospheric flow away from hotspots?
AU - Okal, Emile A.
AU - Stewart, Lisa M.
N1 - Funding Information:
We are gratefult o Michel Bouchon,R ichard Hey, Sylvie le DouaranJ,o hn Sclatera nd many others cientistfso r discussioonv erv ariousa spects of this researchJ.. K. Weisselk indlym adea vailable his latestw ork in the IndianO cean,p rior to publicationJo. e Greenberhge lpedin the studyo f theE ltaninF ractureZ ones eismicityW. e thankM . Kikuchi for theu seo f his programfo r deconvolution of bodyw aves,a ndthe Commissariaat l 'En-ergie Atomique,f or preliminaryd ata from the Kerguelenn etworkT. he repeateuds eof the film chip collectiona t Lamont-DoherGtye ologicaOl b-servatoriys gratefullayc knowledgeTdh.i s research was supportedb y the NationalS cienceF ounda-tion, under grantsE AR-79-03907a nd EAR-81-06106,a nd also partiallyb y the Office of Naval Researchu,n derC ontracNt 00014-79-C-0292.
PY - 1982/1
Y1 - 1982/1
N2 - The regime of strain release along transform faults of the Mid-Oceanic Ridge system is studied. It is shown that earthquakes along certain fracture zones exhibit systematic discrepancies between values of their magnitudes measured at short and long periods, implying a regime of slower strain release, also observed in a pattern of complex body waveshapes. These "slow" fracture zones do not correlate with simple geographic or kinematic properties, but usually occur in the neighborhood of hotspot volcanism, frequently also characterized by gravity and bathymetry anomalies. We propose that regimes of slow strain release may be due to a partial lubrication of the fault along these fracture zones, which may itself be due to asthenospheric flow from the nearby hotspots, along the pattern of pipelines described by Vogt and Johnson and by Morgan.
AB - The regime of strain release along transform faults of the Mid-Oceanic Ridge system is studied. It is shown that earthquakes along certain fracture zones exhibit systematic discrepancies between values of their magnitudes measured at short and long periods, implying a regime of slower strain release, also observed in a pattern of complex body waveshapes. These "slow" fracture zones do not correlate with simple geographic or kinematic properties, but usually occur in the neighborhood of hotspot volcanism, frequently also characterized by gravity and bathymetry anomalies. We propose that regimes of slow strain release may be due to a partial lubrication of the fault along these fracture zones, which may itself be due to asthenospheric flow from the nearby hotspots, along the pattern of pipelines described by Vogt and Johnson and by Morgan.
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U2 - 10.1016/0012-821X(82)90174-1
DO - 10.1016/0012-821X(82)90174-1
M3 - Article
AN - SCOPUS:0019896234
SN - 0012-821X
VL - 57
SP - 75
EP - 87
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
IS - 1
ER -