HUSCAP logo Hokkaido Univ. logo

Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Peer-reviewed Journal Articles, etc >

Was the 1952 Tokachi-oki earthquake (Mw=8.1) a typical underthrust earthquake?: Plate interface reflectivity measurement by an air gun-ocean bottom seismometer experiment in the Kuril Trench

Files in This Item:
GGG13_Q08015.pdf2.23 MBPDFView/Open
Please use this identifier to cite or link to this item:http://hdl.handle.net/2115/52028

Title: Was the 1952 Tokachi-oki earthquake (Mw=8.1) a typical underthrust earthquake?: Plate interface reflectivity measurement by an air gun-ocean bottom seismometer experiment in the Kuril Trench
Authors: Azuma, Ryosuke Browse this author
Murai, Yoshio Browse this author →KAKEN DB
Katsumata, Kei Browse this author →KAKEN DB
Nishimura, Yuichi Browse this author →KAKEN DB
Yamada, Takuji Browse this author
Mochizuki, Kimihiro Browse this author
Shinohara, Masanao Browse this author
Keywords: Kuril Trench
crustal structure
interplate reflectivity
seismic gap
tsunami earthquake
underthrust earthquakes
Issue Date: 25-Aug-2012
Publisher: American Geophysical Union
Journal Title: Geochemistry, Geophysics, Geosystems
Volume: 13
Issue: 8
Start Page: Q08015
Publisher DOI: 10.1029/2012GC004135
Abstract: The Kuril Trench subduction zone is one of the most seismogenic regions, where underthrust earthquakes with M > 8 recur along the trench. The seismic gap between the source areas of the 1973 Nemuro-oki and 2003 Tokachi-oki earthquakes, which are typical underthrust earthquakes faulting with rupture velocities of ~3 km/s, has been ruptured by the 1952 Tokachi-oki earthquake. The seismic gap has also slipped incidental to neighboring asperities. The difference in slip pattern on the plate interface generally appears as a spatial difference in seismic structure on the plate interface, such as a reflectivity of the plate interface. We estimated the crustal velocity structure and analyzed the reflectivity of the plate interface to investigate the physical properties of the plate interface by performing an air gun-ocean bottom seismometer experiment on the along-trench profile across the seismic gap. Strong reflections from the plate interface were observed in the 1952 Tokachi-oki source area including the seismic gap, rather than in the 1973 Nemuro-oki source area. The strong reflectivity of the plate interface in such the seismic gap with an incidental slip suggests that a slip pattern in the corresponding seismic gap would be conditionally stable. The coupling condition in the source areas of the eastern part of the source area of the 1952 earthquake is different from that in source areas of typical underthrust earthquakes, such as the 2003 Tokachi-oki and 1973 Nemuro-oki earthquakes. Our results suggest that the 1952 Tokachi-oki earthquake was a complex earthquake with the characteristic of a tsunami earthquake.
Rights: ©2012 American Geophysical Union
Type: article
URI: http://hdl.handle.net/2115/52028
Appears in Collections:理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)

Submitter: 東 龍介

Export metadata:

OAI-PMH ( junii2 , jpcoar )

MathJax is now OFF:


 

 - Hokkaido University