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Geodetic constraints on afterslip characteristics following the March 9, 2011, Sanriku‐oki earthquake, Japan
Author(s) -
Ohta Yusaku,
Hino Ryota,
Inazu Daisuke,
Ohzono Mako,
Ito Yoshihiro,
Mishina Masaaki,
Iinuma Takeshi,
Nakajima Junichi,
Osada Yukihito,
Suzuki Kensuke,
Fujimoto Hiromi,
Tachibana Kenji,
Demachi Tomotsugu,
Miura Satoshi
Publication year - 2012
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 - 10.1029/2012gl052430
Subject(s) - seismology , geology , hypocenter , foreshock , moment magnitude scale , magnitude (astronomy) , subduction , geodetic datum , slip (aerodynamics) , tide gauge , geodesy , interferometric synthetic aperture radar , aftershock , induced seismicity , sea level , tectonics , synthetic aperture radar , oceanography , physics , geometry , mathematics , remote sensing , astronomy , scaling , thermodynamics
A magnitude 7.3 foreshock occurred at the subducting Pacific plate interface on March 9, 2011, 51 h before the magnitude 9.0 Tohoku earthquake off the Pacific coast of Japan. We propose a coseismic and postseismic afterslip model of the magnitude 7.3 event based on a global positioning system network and ocean bottom pressure gauge sites. The estimated coseismic slip and afterslip areas show complementary spatial distributions; the afterslip distribution is located up‐dip of the coseismic slip for the foreshock and northward of hypocenter of the Tohoku earthquake. The slip amount for the afterslip is roughly consistent with that determined by repeating earthquake analysis carried out in a previous study. The estimated moment release for the afterslip reached magnitude 6.8, even within a short time period of 51h. A volumetric strainmeter time series also suggests that this event advanced with a rapid decay time constant compared with other typical large earthquakes.