Publication Date:
2021-05-19
Description:
It is very regretful that we could not start our project on submarine active faults along the Japan Trench before the devastating Mw 9.0 Tohoku−Oki earthquake on March 11, 2011. Fundamental information for prediction of large earthquakessuch asthedetailed distribution of activefaultswasnotwellknown mainly due to lack of data regarding seafloor topography. To make a more precise submarine active fault map along the trench, we have made detailed seafloor topographic images based on 0.002 degree (about 150m)DEM processed from the original data obtained by Japan Coast Guard and JAMSTEC. Then we have produced anaglyph images of seafloor topography forinterpretationofactivefaults,similarinmannertohowweuseair−photostereosetsforinlandactivefaultinterpretation. Active fault distribution along and around the Japan Trench is rather simple compared with that of the Nankai Trough and/or the southwestern part of the Kuril Trench. As mapped by a previous work(Research Group for Active Faults of Japan, 2001), there are trench−parallel north−dipping thrusts. One of the extensive thrusts extends from off−Sanriku to off−Ibaraki for over 500km, and is probably related to the source fault of the 2011Tohoku− Oki earthquake. Numerous normal faults are depicted on the outer−riseslopeand they are generally short, and may cause M 7 class earthquakes.
Description:
Published
Repository Name:
AquaDocs
Type:
Journal Contribution
,
Refereed
Format:
pp. 148-158
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