Present-day deformation across the southwest Japan arc: Oblique subduction of the Philippine Sea plate and lateral slip of the Nankai forearc

Takao Tabei, Manabu Hashimoto, Shin'ichi Miyazaki, Yusaku Ohta

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)

Abstract

We estimate long-term/permanent crustal deformation in the Nankai forearc, southwest Japan, that accumulated over one earthquake deformation cycle in the Nankai subduction zone. A short-term deformation due to an oblique subduction of the Philippine Sea plate is modeled based on coseismic fault slips associated with interplate thrust earthquakes at the Nankai Trough, and subtracted from the interseismic crustal velocity field observed by GPS. The long-term/permanent deformation left in the data shows arc-parallel movement of the forearc at a rate of 5-10 mm/yr. We interpret that the forearc movement, driven by the oblique plate convergence, is accommodated by steady aseismic slip on the deep portion of the fault plane of the Median Tectonic Line (MTL) on the rear boundary of the Nankai forearc. The rate of the forearc movement is consistent with the geological slip rate of the MTL in the late Quaternary, and also with that expected from deflection of the slip vector of the 1946 Nankai earthquake from the current plate convergence vector.

Original languageEnglish
Pages (from-to)643-647
Number of pages5
Journalearth, planets and space
Volume55
Issue number10
DOIs
Publication statusPublished - 2003
Externally publishedYes

Keywords

  • Global Positioning System
  • Median Tectonic Line
  • Nankai Trough
  • Oblique plate convergence

ASJC Scopus subject areas

  • Geology
  • Space and Planetary Science

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