Rupture process of the 1944 Tonankai earthquake (Ms 8.1) from the inversion of teleseismic and regional seismograms -: art. no. 2497

被引:81
作者
Ichinose, GA
Thio, HK
Somerville, PG
Sato, T
Ishii, T
机构
[1] URS Grp Inc, Pasadena, CA 91101 USA
[2] Ohsaki Res Inst, Chiyoda Ku, Tokyo 1000011, Japan
关键词
Tonankai earthquake; rupture process; waveform inversion; Nankai trough;
D O I
10.1029/2003JB002393
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
[1] We digitized teleseismic and regional records of the 1944 Tonankai earthquake. We used the multiple time window method to invert these records for the spatial and temporal distribution of slip and rake. We assume a 220 x 140 km fault with a spacing of 20 x 20 km and a maximum rupture velocity of 2.5 km/s. The inversion resolved an asperity along the accretionary wedge and under the Shima and Atsumi Peninsulas. The rupture propagated from southwest to northeast, and there was little slip near the hypocenter, consistent with the absence of uplift in the overlying submarine forearc basin. The peak slip is 2.3 m, and the total seismic moment is 2.4 x 10(28) dyn cm (M-w 8.2). We compared the predicted and observed vertical geodetic displacements and inferred that the limit of rupture is consistent with the change from subsidence to uplift west of the Atsumi Peninsula. This suggested that the earthquake did not rupture the plate interface in the Tokai gap. We modeled the tsunami using sea-bottom displacements generated from this slip model. The tide gauge amplitudes and frequency content are consistent with those predicted. Resolution tests from inverting synthetic seismograms computed using a simplified slip model indicated that the combination of teleseismic and regional data sets best recovers the asperity locations and peak slips given similar station geometry and degrees of freedom. An inversion of the synthetic regional data set indicates that slip artifacts can occur early in the rupture process due to many clipped records while the inversion of synthetic teleseismic data set had less resolution and recovered only 50% of the peak slip.
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共 39 条
[1]   POSSIBILITY OF A MAJOR EARTHQUAKE IN TOKAI DISTRICT, JAPAN AND ITS PRE-ESTIMATED SEISMOTECTONIC EFFECTS [J].
ANDO, M .
TECTONOPHYSICS, 1975, 25 (1-2) :69-85
[2]   SOURCE MECHANISMS AND TECTONIC SIGNIFICANCE OF HISTORICAL EARTHQUAKES ALONG NANKAI TROUGH, JAPAN [J].
ANDO, M .
TECTONOPHYSICS, 1975, 27 (02) :119-140
[3]   MOHO DEPTH DETERMINATIONS BASED ON SPECTRAL-RATIO ANALYSIS OF NORSAR LONG-PERIOD P-WAVES [J].
BERTEUSSEN, KA .
PHYSICS OF THE EARTH AND PLANETARY INTERIORS, 1977, 15 (01) :13-27
[4]  
CLAREBOUT JF, 1992, EARTH SOUNDING ANAL
[5]   CURRENT PLATE MOTIONS [J].
DEMETS, C ;
GORDON, RG ;
ARGUS, DF ;
STEIN, S .
GEOPHYSICAL JOURNAL INTERNATIONAL, 1990, 101 (02) :425-478
[6]   ESTIMATION OF CRUSTAL STRUCTURE IN CENTRAL AND WEST JAPAN FROM WAVE-FORM MODELING OF REGIONAL PL WAVES [J].
FUJITA, M ;
NISHIMURA, K .
PURE AND APPLIED GEOPHYSICS, 1993, 140 (04) :569-592
[7]   ESTIMATION OF CRUSTAL STRUCTURE FROM OBSERVED GROUP VELOCITIES OF PL-WAVES IN JAPAN [J].
FUJITA, M ;
NISHIMURA, K .
PURE AND APPLIED GEOPHYSICS, 1991, 137 (03) :233-249
[8]  
HARTZELL SH, 1983, B SEISMOL SOC AM, V73, P1553
[9]  
HERRMANN RB, 1990, SEISMOLOGY, P1
[10]   Source parameters of eastern California and western Nevada earthquakes from regional moment tensor inversion [J].
Ichinose, GA ;
Anderson, JG ;
Smith, KD ;
Zeng, YH .
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, 2003, 93 (01) :61-84