Interplate coupling and backarc spreading in the northernmost district of Nansei-islands, Japan -Geodetic and seismological observations at the Uji-island-

2016 Fiscal Year Final Research Report

• Project/Area Number: 24540458
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Solid earth and planetary physics
• Research Institution: Kagoshima University
• Principal Investigator: GOTO Kazuhiko 鹿児島大学, 理工学域理学系, 教授 (20244220)
• Project Period (FY): 2012-04-01 – 2017-03-31
• Keywords: プレート間カップリング / 南西諸島 / 沖縄トラフ / GNSS観測 / 地震観測

Outline of Final Research Achievements

The geodetic and seismological observations at Uji-island located at the rim of the Okinawa-trough in the northernmost district of the Nansei-islands reveal that the north end region of the Okinawa-trough is enlarged at speed of approximately 5mm/yr and the seismic activity of the south side region than around 31.5°N was low for the events of magnitude larger than 1.5 in the period after at least 2002. This low seismic activity, however, changed completely by the occurrence of earthquake of M7.1 west off Satsuma-peninsula on November 14, 2015, which is the largest event in the northern region of Okinawa trough in the past. The characteristic of the larger earthquakes occur in this region becomes clear for the first time by analyzing this M7.1 event, in which the data of the nearest observation station Uji-island play an important role.

Free Research Field

数物系科学