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Interplate locking condition derived from seafloor geodetic data at the northernmost part of the Suruga Trough, Japan
Author(s) -
Yasuda Kenji,
Tadokoro Keiichi,
Ikuta Ryoya,
Watanabe Tsuyoshi,
Nagai Satoru,
Okuda Takashi,
Fujii Cosmo,
Sayanagi Keizo
Publication year - 2014
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 - 10.1002/2014gl060945
Subject(s) - geology , trough (economics) , subduction , seismology , seafloor spreading , geodetic datum , slip (aerodynamics) , geodesy , tectonics , paleontology , physics , thermodynamics , economics , macroeconomics
We observed seafloor crustal deformation at two observation sites on opposite sides of the Suruga Trough off Japan from 2005 to 2011 to investigate the interplate locking condition at the source region of the anticipated great subduction earthquake, named Tokai earthquake. We estimated the displacement velocity vectors relative to the Amurian Plate on the basis of repeated observations. Our results at the two points, Suruga northeast and Suruga northwest (SNW) were 42 ± 8 mm/yr toward N94 ± 3°W and 39 ± 11 mm/yr toward N84 ± 9°W, respectively. These directions are the same as those measured at on‐land GPS stations. The magnitudes of the velocity vectors indicate a significant shortening of approximately 4 mm/yr between SNW and on‐land GPS stations located to the west of the Suruga Trough. The results show that the plate interface is strongly locked (no slip) shallower than the source region of the anticipated Tokai earthquake.