TY - JOUR
T1 - Was the 2011 Tohoku-Oki earthquake preceded by aseismic preslip? Examination of seafloor vertical deformation data near the epicenter
AU - Hino, R.
AU - Inazu, D.
AU - Ohta, Y.
AU - Ito, Y.
AU - Suzuki, S.
AU - Iinuma, T.
AU - Osada, Y.
AU - Kido, M.
AU - Fujimoto, H.
AU - Kaneda, Y.
N1 - Funding Information:
Acknowledgments Deployment and retrieval of OBPRs were conducted by R/V Ryofu-maru and R/V Keifu-maru of Japan Meteorological Agency, R/V Kairei and R/V Natsushima of Japan Agency for Marine-Earth Science and Technology, and R/V Hakuho-maru and R/V Tansei-maru of the University of Tokyo. We thank the captains and crews of these vessels for their assistance. Thoughtful comments by Roland Bürgmann and an anonymous reviewer were helpful in improving this manuscript. This study was supported by the research project ‘‘Research concerning Interaction between the Tokai, Tonankai and Nankai Earthquakes’’ of the Ministry of Education, Culture, Sports, Science and Technology, and by Grant-in-Aid for Scientific Research (A) 20244070 from the Japan Society for the Promotion of Science. The Generic Mapping Tools (Wessel and Smith 1998) were used for creating the figures.
Publisher Copyright:
© 2013, The Author(s).
PY - 2014/9
Y1 - 2014/9
N2 - Ocean-bottom pressure records obtained near the epicenter of the 2011 Tohoku-Oki earthquake were examined to test whether the earthquake was preceded by substantial precursory crustal deformation. The seafloor data enabled us to search for small-scale preslip near the epicenter that would be difficult to identify from terrestrial geodetic data. After treating the data to reduce nontectonic fluctuations, we obtained a time series of seafloor vertical deformation in the epicentral region with a noise level of 2–4 cm. No significant crustal deformation related to preslip was detected in the period of roughly a day before the mainshock, whereas postseismic deformation associated with the largest foreshock 2 days before the mainshock was apparent. From our quantitative estimate of the sensitivity of the seafloor network in detecting slip on the plate interface, we conclude that the Tohoku-Oki earthquake was not preceded by preslip with moment release greater than moment magnitude (Mw) 6.2 in the vicinity of the hypocenter or greater than Mw 6.0 along the subduction interface near the trench.
AB - Ocean-bottom pressure records obtained near the epicenter of the 2011 Tohoku-Oki earthquake were examined to test whether the earthquake was preceded by substantial precursory crustal deformation. The seafloor data enabled us to search for small-scale preslip near the epicenter that would be difficult to identify from terrestrial geodetic data. After treating the data to reduce nontectonic fluctuations, we obtained a time series of seafloor vertical deformation in the epicentral region with a noise level of 2–4 cm. No significant crustal deformation related to preslip was detected in the period of roughly a day before the mainshock, whereas postseismic deformation associated with the largest foreshock 2 days before the mainshock was apparent. From our quantitative estimate of the sensitivity of the seafloor network in detecting slip on the plate interface, we conclude that the Tohoku-Oki earthquake was not preceded by preslip with moment release greater than moment magnitude (Mw) 6.2 in the vicinity of the hypocenter or greater than Mw 6.0 along the subduction interface near the trench.
KW - Interplate megathrust earthquake
KW - Ocean-bottom pressure monitoring
KW - Precursory slip
KW - Seafloor vertical deformation
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U2 - 10.1007/s11001-013-9208-2
DO - 10.1007/s11001-013-9208-2
M3 - Article
AN - SCOPUS:84920253995
VL - 35
SP - 181
EP - 190
JO - Marine Geophysical Researches
JF - Marine Geophysical Researches
SN - 0025-3235
IS - 3
ER -