Fault geometry of the 2004 off the Kii peninsula earthquake inferred from offshore pressure waveforms

被引:13
作者
Matsumoto, H
Mikada, H
机构
[1] Japan Agcy Marine Earth Sci & Technol, IFREE, Deep Sea Res Program, Yokosuka, Kanagawa 2370061, Japan
[2] Kyoto Univ, Dept Civil & Earth Resources Engn, Sakyo Ku, Kyoto 6068501, Japan
来源
EARTH PLANETS AND SPACE | 2005年 / 57卷 / 03期
关键词
the 2004 off the Kii peninsula earthquake; pressure gauge; tsunami; seismic fault;
D O I
10.1186/BF03351809
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
We could Successfully obtain water pressure fluctuations after a series of two off the Kii peninsula earthquakes that took place on September 5 in 2004, using two pressure gauges deployed at deep ocean-bottom off Muroto. The earthquakes caused two tsunamis in the southern coast of the southwestern Japan with maximum wave heights of 0.9 m, and we could identify the tsunami signals from the acquired dataset ca. 20 min before the arrivals of the tsunamis to the coastline nearest to the sensors. Two earthquakes are assumed as one for a fore-shock and the other for a main-shock. Although seismological studies, without aftershock distributions, showed a lack of constraints to distinguish if the main-shock was caused by either southwest dipping fault or by the other, i.e., northeast dipping fault, we found that the difference in the pressure fluctuations for the tsunamis could attribute to the determination of the fault plane in the fault models. In this paper, we evaluate the fault geometry of the main shock by using tsunami waveforms obtained by those unique instruments in following procedure: (1) We first simulate pressure waveforms caused by earthquakes of the two fault geometries, one for southwest dipping place and the other for the northeast, at the location of the pressure gauges, and (2) we then compare the simulated results with observed waveforms. Our results demonstrate that the main-shock should be caused by a fault whose strike lies in north west-to-southeast with a clip towards southwest direction.
引用
收藏
页码:161 / 166
页数:6
相关论文
共 15 条
[1]   Compound fault rupture during the 2004 off the Kii peninsula earthquake (M 7.4) inferred from highly resolved coseismic sea-surface deformation [J].
Baba, T ;
Cummins, PR ;
Hori, T .
EARTH PLANETS AND SPACE, 2005, 57 (03) :167-172
[2]   Crustal deformations in Kii peninsula associated with the SE off the Kii peninsula earthquake sequence of September 5, 2004 derived from dense GPS observations [J].
Hashimoto, M ;
Onoue, K ;
Ohya, F ;
Hoso, Y ;
Segawa, K ;
Sato, K ;
Fujita, Y .
EARTH PLANETS AND SPACE, 2005, 57 (03) :185-190
[3]   Micro-tsunami from a local interplate earthquake detected by cabled offshore tsunami observation in northeastern Japan [J].
Hino, R ;
Tanioka, Y ;
Kanazawa, T ;
Sakai, S ;
Nishino, M ;
Suyehiro, K .
GEOPHYSICAL RESEARCH LETTERS, 2001, 28 (18) :3533-3536
[4]   Source depth dependence of micro-tsunamis recorded with ocean-bottom pressure gauges:: the January 28, 2000 Mw 6.8 earthquake off Nemuro Peninsula, Japan [J].
Hirata, K ;
Takahashi, H ;
Geist, E ;
Satake, K ;
Tanioka, Y ;
Sugioka, H ;
Mikada, H .
EARTH AND PLANETARY SCIENCE LETTERS, 2003, 208 (3-4) :305-318
[5]   Real-time geophysical measurements on the deep seafloor using submarine cable in the southern Kurile subduction zone [J].
Hirata, K ;
Aoyagi, M ;
Mikada, H ;
Kawaguchi, K ;
Kaiho, Y ;
Iwase, R ;
Morita, S ;
Fujisawa, I ;
Sugioka, H ;
Mitsuzawa, K ;
Suyehiro, K ;
Kinoshita, H ;
Fujiwara, N .
IEEE JOURNAL OF OCEANIC ENGINEERING, 2002, 27 (02) :170-181
[6]  
Hirt C.W., 1975, SOLA-A Numerical Solution Algorithm for Transient Fluid Flows
[7]  
KATAOKA S, 1999, P 2 US JAP WORKSH AD, P347
[8]  
MATSUMOTO H, 2004, ANN J COAST ENG JSCE, V51, P281
[9]  
Matsumoto Koji., 2000, Journal of Oceanography, V56, P567, DOI DOI 10.1023/A:1011157212596
[10]   Simulation of tsunami induced by dynamic displacement of seabed due to seismic faulting [J].
Ohmachi, T ;
Tsukiyama, H ;
Matsumoto, H .
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, 2001, 91 (06) :1898-1909