Slip history of the 1994 Sanriku-Haruka-Oki, Japan, earthquake deduced from strong-motion data

1997 ◽  
Vol 87 (4) ◽  
pp. 918-931 ◽  
Author(s):  
Wataru Nakayama ◽  
Minoru Takeo
Keyword(s):  
Seismic Waves ◽  
Time Window ◽  
Strong Motion ◽  
Rupture Process ◽  
Multiple Time ◽  
Strong Motion Data ◽  
Motion Data ◽  
The Third ◽  
Slip History ◽  
Double Couple

Abstract We analyzed the seismic waves of the 1994 Sanriku-Haruka-Oki earthquake (Mw = 7.7), which occurred in the aftershock area of the 1968 Tokachi-Oki earthquake (Mw = 8.2). Applying a multiple-time window inversion scheme to near-source strong-motion data, we obtained a detailed spatiotemporal rupture process and compared it with that of the Tokachi-Oki earthquake. The fault geometry is constructed based on the aftershock distribution. The obtained rupture model is consistent with the CMT solution even for a non-double-couple component. The total seismic moment is 4.0 × 1020 N-m. Large slips are concentrated in three asperities: the first asperity centers about 40 km south and 50 km west from the hypocenter with a maximum slip of 4.4 m, the second one centers about 60 km west from the hypocenter with a maximum slip of 2.2 m, and the third one lies about 110 km west from the hypocenter with a maximum slip of 2.6 m. The obtained moment rate and the duration on the first and second asperities are lower and much longer than those on the third asperity, respectively. The first asperity does not overlap with an area of large slip during the Tokachi-Oki earthquake, but the second or third seem to overlap with or be adjacent to the asperity of the Tokachi-Oki earthquake. Our inversion result also shows an abrupt change of the rupture velocity (from 1.8 to 3.0 km/sec) at the central part of the fault plane. A difference of the seismic coupling between the oceanic and the continental lithospheres at the trenchward side and at the landward side of the 143° E meridian seems to affect the rupture process of this earthquake.

scholarly journals Rupture process of the 1987 Superstition Hills earthquake from the inversion of strong-motion data

1990 ◽  
Vol 80 (5) ◽  
pp. 1079-1098 ◽  
Author(s):  
David J. Wald ◽  
Donald V. Helmberger ◽  
Stephen H. Hartzell
Keyword(s):  
Small Area ◽  
Strong Motion ◽  
Rupture Process ◽  
Imperial Valley ◽  
Strong Motion Records ◽  
Motion Data ◽  
Single Asperity ◽  
The Third ◽  
Rupture Model ◽  
Stress Drops

Abstract A pair of significant earthquakes occurred on conjugate faults in the western Imperial Valley involving the through-going Superstition Hills fault and the Elmore Ranch cross fault. The first event was located on the Elmore Ranch fault, Ms = 6.2, and the larger event on the Superstition Hills fault, Ms = 6.6. The latter event is seen as a doublet teleseismically with the amplitudes in the ratio of 1:2 and delayed by about 8 sec. This 8-sec delay is also seen in about a dozen strong-motion records. These strong-motion records are used in a constrained least-squares inversion scheme to determine the distribution of slip on a 2-D fault. Upon closer examination, the first of the doublets was found to be itself complex requiring two episodes of slip. Thus, the rupture model was allowed to have three separate subevents, treated as separate ruptures, with independent locations and start times. The best fits were obtained when all three events initiated at the northwestern end of the fault near the intersection of the cross-fault. Their respective delays are 2.1 and 8.6 sec relative to the first subevent, and their moments are 0.4, 0.9, and 3.5 × 1025 dyne-cm, which is about half of that seen teleseismically. This slip distribution suggests multi-rupturing of a single asperity with stress drops of 60, 200, and 15 bars, respectively. The first two subevents were confined to a small area around the epicenter while the third propagated 18 km southwestward, compatible with the teleseismic and afterslip observations.

Classification of Main Shocks and Aftershocks in the NGA-West2 Database

2014 ◽  
Vol 30 (3) ◽  
pp. 1257-1267 ◽  
Author(s):  
Kathryn E. Wooddell ◽  
Norman A. Abrahamson
Keyword(s):  
Time Window ◽  
Strong Motion ◽  
Data Sets ◽  
Horizontal Distance ◽  
Strong Motion Data ◽  
Motion Data ◽  
Rupture Plane ◽  
Main Shocks ◽  
Short Period ◽  
Surface Projection

Previous studies have found a systematic difference between short-period ground motions from aftershocks and main shocks, but have not used a consistent methodology for classifying earthquakes in strong motion data sets. A method for unambiguously classifying earthquakes in strong motion data sets is developed. The classification is based on the Gardner and Knopoff time window, but with a distance window based on a new distance metric, CRJB, defined as the shortest horizontal distance between the centroid of the surface projection of the potential aftershock rupture plane and the surface projection of the main shock rupture plane. Class 2 earthquakes are earthquakes that have a CRJB distance less than a selected limit and within a time window appropriate for aftershocks. All other earthquakes are classified as Class 1. For maximum CRJB of 0 km and 40 km, 11% and 36% of the earthquakes in the NGA-West2 database are Class 2 events, respectively.

scholarly journals Ground motion and rupture process of the 2003 Tokachi-oki earthquake obtained from strong motion data of K-NET and KiK-net

2004 ◽  
Vol 56 (3) ◽  
pp. 317-322 ◽  
Author(s):  
Ryou Honda ◽  
Shin Aoi ◽  
Nobuyuki Morikawa ◽  
Haruko Sekiguchi ◽  
Takashi Kunugi ◽  
...  
Keyword(s):  
Ground Motion ◽  
Strong Motion ◽  
Rupture Process ◽  
Strong Motion Data ◽  
Motion Data

scholarly journals Rupture process of the 2005 West Off Fukuoka Prefecture earthquake obtained from strong motion data of K-NET and KiK-net

2006 ◽  
Vol 58 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Haruko Sekiguchi ◽  
Shin Aoi ◽  
Ryou Honda ◽  
Nobuyuki Morikawa ◽  
Takashi Kunugi ◽  
...  
Keyword(s):  
Strong Motion ◽  
Rupture Process ◽  
Strong Motion Data ◽  
Fukuoka Prefecture ◽  
Motion Data

scholarly journals Kinematic rupture process of the 2007 Tocopilla earthquake and its main aftershocks from teleseismic and strong-motion data

2010 ◽  
Vol 182 (3) ◽  
pp. 1411-1430 ◽  
Author(s):  
S. Peyrat ◽  
R. Madariaga ◽  
E. Buforn ◽  
J. Campos ◽  
G. Asch ◽  
...  
Keyword(s):  
Strong Motion ◽  
Rupture Process ◽  
Strong Motion Data ◽  
Motion Data

scholarly journals Rupture process of the 2011 Tohoku-Oki mega-thrust earthquake (M9.0) inverted from strong-motion data

2011 ◽  
Vol 38 (7) ◽  
pp. n/a-n/a ◽  
Author(s):  
Wataru Suzuki ◽  
Shin Aoi ◽  
Haruko Sekiguchi ◽  
Takashi Kunugi
Keyword(s):  
Strong Motion ◽  
Rupture Process ◽  
Strong Motion Data ◽  
Motion Data
Sign in / Sign up

Export Citation Format

Share Document