Gravity Recovery and Climate Experiment（GRACE） observations have been used to de-tect the co-seismic and post-seismic gravity field variations due to the Mw=9.3 Sumatra-Andaman earthquake that occurred on December 2...Gravity Recovery and Climate Experiment（GRACE） observations have been used to de-tect the co-seismic and post-seismic gravity field variations due to the Mw=9.3 Sumatra-Andaman earthquake that occurred on December 26,2004.This article focuses on investigating some gravita-tional effects caused by this huge earthquake.We computed the geoid height changes,the equivalent water height（EWH） changes,and the gravity changes using the GRACE Level-2 monthly spherical harmonic（SH） solutions released by University of Texas Center for Space Research（UTCSR）.The GRACE results agree well with the prediction by a dislocation model and are consistent with the results obtained by some previous scholars.In particular,we calculated the three components of the gravity gradient variations and found that they can recover the seismic-related signature more sensitively due to a certain degree of amplification of the signals.A positive-negative-positive mode predominates in the spatial distribution of the horizontal components of the gravity gradient variations,which is possibly attributed to the anomalies in the crustal density distribution caused by the uplift-subduction effect of the dip-slip earthquake.Moreover,the latitude components of the gravity gradient changes show strong suppression of the north-south stripes,which is due to the along-orbit measurements of the two GRACE satellites.We conclude that the posi-tive-negative-positive mode in latitude gravity gradient changes would be a more sensitive fea-ture to detect the deformations of some major dip-slip earthquakes by GRACE data.展开更多
The mode serials of the Earth’s free oscillation provide some important information on the Earth’s deep structure and superconducting gravimeters （SG） can investigate the phenomena of the Earth’s free oscillation...The mode serials of the Earth’s free oscillation provide some important information on the Earth’s deep structure and superconducting gravimeters （SG） can investigate the phenomena of the Earth’s free oscillations with high accuracy. The great Sumatra-Andaman earthquake fully excited the Earth’s free oscillations and these signals were perfectly recorded by five superconducting gravimeters in the globe. After the pre-treatment and spectral analysis on the SG observation data, we obtained the experimented mode serials of the Earth’s free oscillations consisting of 147 modes with GGP station data. These observed modes were themselves some new important data for the study of the Earth’s deep structure. On the basis of the discussions on some checked inner-core-sensitive modes, we distinguished three layers from the inner core, and the boundary of the upper layer was compatible with the formerly known transition zone in the inner core based on seismic body waves and supported that there were the hemispherical variation and very lower shear velocity zone in the lower inner core.展开更多
We analyzed the seismic waveforms from the December 26, 2004 Sumatra-Andaman earthquake recorded at broadband seismic stations in western Europe. Previous studies involving of the beam-forming technique and high frequ...We analyzed the seismic waveforms from the December 26, 2004 Sumatra-Andaman earthquake recorded at broadband seismic stations in western Europe. Previous studies involving of the beam-forming technique and high frequency analysis suggest that the earthquake ruptured with a duration of around 500 s. This very long duration makes P wave overlap with later arrivals such as PP wave, which follows P in about 200 s. Since P waves are crucial for modeling earthquake processes, we propose an iterative method to separate P and PP waveforms. The separated P waveform confirms a second large energy release around 300 s after the initial rupture. The iterative signal separation technique is particularly useful for mixed signals that are not independent and the number of recording stations far exceeds number of mixed signal sources.展开更多
The 0S2-0S54 spheroidal modes of Earth＇s free oscillations, triggered by the great Sumatra-Andaman earthquake of 26 December 2004 are retrieved from VHZ data recorded by seven upgraded stations of China Digital Seism...The 0S2-0S54 spheroidal modes of Earth＇s free oscillations, triggered by the great Sumatra-Andaman earthquake of 26 December 2004 are retrieved from VHZ data recorded by seven upgraded stations of China Digital Seismograph Network （CDSN）. We compare these spheroidal modes with theoretical free oscillation spectra calculated from the Preliminary Reference Earth Model （PREM） and find a coincidence between their periods. Spectral splitting phenomenon is observed obviously in 0S2, 0S3, 0S4, 2S1 and 1S2 free oscillation modes. What is most noticeable is that the oscillation mode 2S1 is reported for the second time （the first time by Rosat et al） without any data stacking. We simulated the split singlet of 0S2 mode on seven CDSN stations based on general focal mechanism and seismic moment of the earthquake. The result shows that seismic moment of the earthquake can reach 10^23 N.m. We also find that the recording of Earth＇s free oscillations carries abundant information of source mechanism and earthquake location, which is applicable to the detailed study of source rupture parameters.展开更多
Continuous global positioning system （GPS） in northern Sumatra detected signal of the ongoing physical process of postseismic deformation after the M9.2 2004 Sumatra-Andaman earthquake. We analyze the character- ist...Continuous global positioning system （GPS） in northern Sumatra detected signal of the ongoing physical process of postseismic deformation after the M9.2 2004 Sumatra-Andaman earthquake. We analyze the character- istics of postseismic deformation of the 2004 earthquake based on GPS networks operated by BIG, and the others named AGNeSS, and SuGAr networks located in northern Sumatra. We use a simple analytical logarithmic and exponential function to evaluate the postseismic deforma- tion parameters of the 2004 earthquake. We find that GPS data in northern Sumatra during time periods of 2005-2012 are fit better using the logarithmic function with dog of 104.2 ± 0.1 than using the exponential function. Our result clearly indicates that other physical mechanisms of post- seismic deformation should be taken into account rather than a single physical mechanism of afterslip only.展开更多
The characteristics of seismic water level fluctuations of the two Sumatra-Andaman strong earthquakes with magnitude 8.7 and 8.5 on December 26,2004 and March 29,2005 recorded at Jiaji well,Qionghai,Hainan were analyz...The characteristics of seismic water level fluctuations of the two Sumatra-Andaman strong earthquakes with magnitude 8.7 and 8.5 on December 26,2004 and March 29,2005 recorded at Jiaji well,Qionghai,Hainan were analyzed,the features of the infrequent "step" changes of well water level after the two earthquakes were also analyzed and the mechanism of the "step change" of well water level was discussed.Then the high-sample-rate digital observation data of seismically-induced water level fluctuations of the Sumatra-Andaman strong earthquakes with magnitude 8.7 and 8.5 recorded at Nanbin well,Sanya and Tanniu well,Wenchang were analyzed.The results suggest that the dominant period of the seismic well water level fluctuation in all three wells was comparatively accordant,the amplitudes of seismic water level fluctuation of the same earthquake in different wells were clearly different,the time duration of seismic water level fluctuations of different earthquakes at the same well was also clearly different.展开更多
Large earthquakes cause observable changes in the Earth’s gravity field,which have been detected by the Gravity Recovery and Climate Experiment(GRACE).Since most previous studies focus on the detection of near-field ...Large earthquakes cause observable changes in the Earth’s gravity field,which have been detected by the Gravity Recovery and Climate Experiment(GRACE).Since most previous studies focus on the detection of near-field gravity effects,this study provides the results from the medium-to far-field gravity changes caused by the 2004 Sumatra-Andaman earthquake that are recorded within GRACE monthly solutions.Utilizing a spherical-earth dislocation model we documented that large-scale signals predominate in the global field of the coseismic gravity changes caused by the earthquake.After removing the near-field effects,the coseismic gravity changes show a negative anomaly feature with an average magnitude of-0.18×10-8 m·s-2 in the region ranging~40°from the epicenter,which is considered as the'medium ffield'in this study.From the GRACE data released by Center for Space Research from August 2002 to December 2008,we retrieved the large-scale gravity changes smoothed with 3000 km Gaussian ffilter.The results show that the coseismic gravity changes detected by GRACE in the medium field have an average of(-0.20±0.06)×10-8 m·s-2,which agrees with the model prediction.The detection confirms that GRACE is sensitive to large-scale medium-field coseismic gravitational effects of mega earthquakes,and also validates the spherical-earth dislocation model in the medium field from the perspective of satellite gravimetry.展开更多
Sumatra-Andaman Large Earthquake on Dec. 26,2004 generated not only the Indian Ocean Tsunami but also the Earth's free oscillations (EFO). The signals of Earth's free oscillations were perfectly re-corded by t...Sumatra-Andaman Large Earthquake on Dec. 26,2004 generated not only the Indian Ocean Tsunami but also the Earth's free oscillations (EFO). The signals of Earth's free oscillations were perfectly re-corded by the superconducting gravimeter C0-32 at Wuhan station in China. After the pre-treatment and spectral analysis on the observational data from Wuhan station,we obtained more than ninety EFO modes including 42 fundamental modes,2 radial modes and 49 harmonic modes. On the basis of the discussions on some observed harmonic modes and abnormal splitting phenomena,we considered that the real rigidity might be lower than the theoretical prediction of PREM model in the inner core and however the anisotropy of compressive wave was brightly higher than the present estimations in the inner core. This suggested that the anisotropy of the inner core could be much more complicated than our present understanding,and there might be some new geophysical phenomena in the formation process of the inner core.展开更多
The Sumatra-Andaman earthquake on December 26, 2004 is the first well recorded gigantic earthquake (moment magnitude MW 9.3) by modern broadband seismic and Global Positioning System networks. The rich seismic and geo...The Sumatra-Andaman earthquake on December 26, 2004 is the first well recorded gigantic earthquake (moment magnitude MW 9.3) by modern broadband seismic and Global Positioning System networks. The rich seismic and geodetic recordings have documented unprecedented details about the earthquake rupture, coseismic and postseismic deformations. This is a report of detailed images of the rupture process using the first-arriving compressional waves recorded by the China National Digital Seismic Network (CNDSN). An improved imaging condition was employed to account for the sparse distribution of the CNDSN stations. The resulting images are consistent with the major rupture features reported by previous seismic and geodetic studies. It is found that the earthquake rupture initiated at offshore of northwestern Sumatra and propagated in the north northwest direction at a speed of 2.7 ± 0.2 km/s. The rupture continued for at least 420 s and extended about 1200-1300 km along the Andaman trough with two bursts of seismic energy.展开更多
We address the role of the concave and convex arcs （as observed from the subducting plate） on the deformation occurring along the Myanmar-Andaman-Sumatra margin. We categorize the pre- and post-seismic deformations ...We address the role of the concave and convex arcs （as observed from the subducting plate） on the deformation occurring along the Myanmar-Andaman-Sumatra margin. We categorize the pre- and post-seismic deformations of the lithosphere using earthquake database occurring either prior to 26th December 2004 Mw 9.3 off-Sumatra mega-event or after the incidence. Analysis under pre-seismic domain shows that area near Sumatra records highest seismicity, which largely drops in the area past the North Andaman, and further increases towards north. Shallowest depth and mini- mum dip of the subducting lithosphere is recorded at the central segment where the arc transformed into concave shape. The annual moment energy release during earthquake decreases to more than two orders of magnitude past the North Andaman towards north under post-seismic deformation phase. Higher depths of continuity of events are presumably associated with more dipping Benioff zones in both the Indo-Myanmar and Andaman-Nicobar convex arcs. These observations obviously account for tectonic subdivision of the margin near concave shape arc around the central part. Absence of vol- canism, presence of splay faults in the back-arc, sharp reduction in seismicity near central segment are interpreted to be caused by major tectonic impact of the NNE-ward converging buoyant Ninety-east Ridge against the Asian Plate. Shallowest dip, small elastic thickness, weak converging Indian litho- sphere, and evidences of series of en-echelon blocks off the eastern side of the broken northern Ninety- east Ridge might be incapable of generating great earthquake in this area.展开更多
We analyze co-seismic displacement field of the 26 December 2004, giant Sumatra–Andaman earthquake derived from Global Position System observations,geological vertical measurement of coral head, and pivot line observ...We analyze co-seismic displacement field of the 26 December 2004, giant Sumatra–Andaman earthquake derived from Global Position System observations,geological vertical measurement of coral head, and pivot line observed through remote sensing. Using the co-seismic displacement field and AK135 spherical layered Earth model, we invert co-seismic slip distribution along the seismic fault. We also search the best fault geometry model to fit the observed data. Assuming that the dip angle linearly increases in downward direction, the postfit residual variation of the inversed geometry model with dip angles linearly changing along fault strike are plotted. The geometry model with local minimum misfits is the one with dip angle linearly increasing along strike from 4.3oin top southernmost patch to 4.5oin top northernmost path and dip angle linearly increased. By using the fault shape and geodetic co-seismic data, we estimate the slip distribution on the curved fault. Our result shows that the earthquake ruptured ＊200-km width down to a depth of about 60 km.0.5–12.5 m of thrust slip is resolved with the largest slip centered around the central section of the rupture zone78N–108N in latitude. The estimated seismic moment is8.2 9 1022 N m, which is larger than estimation from the centroid moment magnitude（4.0 9 1022 N m）, and smaller than estimation from normal-mode oscillation data modeling（1.0 9 1023 N m）.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 40974015,40637034)the Fund of Key Laboratory of Geodynamic Geodesy, Chinese Academy of Sciences (No. 09-18)the Fund of Key Laboratory of Geospace Environment and Geodesy,Ministry of Education,China (No. 07-12)
文摘Gravity Recovery and Climate Experiment（GRACE） observations have been used to de-tect the co-seismic and post-seismic gravity field variations due to the Mw=9.3 Sumatra-Andaman earthquake that occurred on December 26,2004.This article focuses on investigating some gravita-tional effects caused by this huge earthquake.We computed the geoid height changes,the equivalent water height（EWH） changes,and the gravity changes using the GRACE Level-2 monthly spherical harmonic（SH） solutions released by University of Texas Center for Space Research（UTCSR）.The GRACE results agree well with the prediction by a dislocation model and are consistent with the results obtained by some previous scholars.In particular,we calculated the three components of the gravity gradient variations and found that they can recover the seismic-related signature more sensitively due to a certain degree of amplification of the signals.A positive-negative-positive mode predominates in the spatial distribution of the horizontal components of the gravity gradient variations,which is possibly attributed to the anomalies in the crustal density distribution caused by the uplift-subduction effect of the dip-slip earthquake.Moreover,the latitude components of the gravity gradient changes show strong suppression of the north-south stripes,which is due to the along-orbit measurements of the two GRACE satellites.We conclude that the posi-tive-negative-positive mode in latitude gravity gradient changes would be a more sensitive fea-ture to detect the deformations of some major dip-slip earthquakes by GRACE data.
基金supported jointly by the National Natural Science Foundation of China (Nos. 40974046,90814009 and 40730316)the Natural Science Foundation of Hubei Province (No. 2008CDB389)the Knowledge Innovation Project of Chinese Academy of Sciences (No. KZCX2-YW-133)
文摘The mode serials of the Earth’s free oscillation provide some important information on the Earth’s deep structure and superconducting gravimeters （SG） can investigate the phenomena of the Earth’s free oscillations with high accuracy. The great Sumatra-Andaman earthquake fully excited the Earth’s free oscillations and these signals were perfectly recorded by five superconducting gravimeters in the globe. After the pre-treatment and spectral analysis on the SG observation data, we obtained the experimented mode serials of the Earth’s free oscillations consisting of 147 modes with GGP station data. These observed modes were themselves some new important data for the study of the Earth’s deep structure. On the basis of the discussions on some checked inner-core-sensitive modes, we distinguished three layers from the inner core, and the boundary of the upper layer was compatible with the formerly known transition zone in the inner core based on seismic body waves and supported that there were the hemispherical variation and very lower shear velocity zone in the lower inner core.
基金supported by CAS fund(KZCX2-YW-116-1)National Natural Science Foundation of China(40821160549 and 41074032)China Earthquake Administration fund(200808078)
文摘We analyzed the seismic waveforms from the December 26, 2004 Sumatra-Andaman earthquake recorded at broadband seismic stations in western Europe. Previous studies involving of the beam-forming technique and high frequency analysis suggest that the earthquake ruptured with a duration of around 500 s. This very long duration makes P wave overlap with later arrivals such as PP wave, which follows P in about 200 s. Since P waves are crucial for modeling earthquake processes, we propose an iterative method to separate P and PP waveforms. The separated P waveform confirms a second large energy release around 300 s after the initial rupture. The iterative signal separation technique is particularly useful for mixed signals that are not independent and the number of recording stations far exceeds number of mixed signal sources.
基金State Key Fundamental Research Development Plan Project (2001CB711005) National Natural Science Founda-tion of China (40374012)
文摘The 0S2-0S54 spheroidal modes of Earth＇s free oscillations, triggered by the great Sumatra-Andaman earthquake of 26 December 2004 are retrieved from VHZ data recorded by seven upgraded stations of China Digital Seismograph Network （CDSN）. We compare these spheroidal modes with theoretical free oscillation spectra calculated from the Preliminary Reference Earth Model （PREM） and find a coincidence between their periods. Spectral splitting phenomenon is observed obviously in 0S2, 0S3, 0S4, 2S1 and 1S2 free oscillation modes. What is most noticeable is that the oscillation mode 2S1 is reported for the second time （the first time by Rosat et al） without any data stacking. We simulated the split singlet of 0S2 mode on seven CDSN stations based on general focal mechanism and seismic moment of the earthquake. The result shows that seismic moment of the earthquake can reach 10^23 N.m. We also find that the recording of Earth＇s free oscillations carries abundant information of source mechanism and earthquake location, which is applicable to the detailed study of source rupture parameters.
基金funded by the PLN APJ of Sukabumi No.203/060/APJ-SKI/2010Indonesia Endowment Fund for Education(LPDP) No.PRJ1048/LPDP/2015the Australian Department of Foreign Affairs and Trade(DFAT) for Graduate Research on Earthquake and Active Tectonics at the Bandung Institute of Technology
文摘Continuous global positioning system （GPS） in northern Sumatra detected signal of the ongoing physical process of postseismic deformation after the M9.2 2004 Sumatra-Andaman earthquake. We analyze the character- istics of postseismic deformation of the 2004 earthquake based on GPS networks operated by BIG, and the others named AGNeSS, and SuGAr networks located in northern Sumatra. We use a simple analytical logarithmic and exponential function to evaluate the postseismic deforma- tion parameters of the 2004 earthquake. We find that GPS data in northern Sumatra during time periods of 2005-2012 are fit better using the logarithmic function with dog of 104.2 ± 0.1 than using the exponential function. Our result clearly indicates that other physical mechanisms of post- seismic deformation should be taken into account rather than a single physical mechanism of afterslip only.
基金sponsored by Joint Earthquake Science Foundation of China (105086)
文摘The characteristics of seismic water level fluctuations of the two Sumatra-Andaman strong earthquakes with magnitude 8.7 and 8.5 on December 26,2004 and March 29,2005 recorded at Jiaji well,Qionghai,Hainan were analyzed,the features of the infrequent "step" changes of well water level after the two earthquakes were also analyzed and the mechanism of the "step change" of well water level was discussed.Then the high-sample-rate digital observation data of seismically-induced water level fluctuations of the Sumatra-Andaman strong earthquakes with magnitude 8.7 and 8.5 recorded at Nanbin well,Sanya and Tanniu well,Wenchang were analyzed.The results suggest that the dominant period of the seismic well water level fluctuation in all three wells was comparatively accordant,the amplitudes of seismic water level fluctuation of the same earthquake in different wells were clearly different,the time duration of seismic water level fluctuations of different earthquakes at the same well was also clearly different.
基金funded in parts by the Natural Science Foundation of China(grant Nos.40974015,41128003,41174011 and41021061)the Open Fund of Key Laboratory of Geo-dynamic Geodesy of Chinese Academy(No.09-18)the Open Fund of Key Laboratory of Geospace Environment and Geodesy,Ministry of Education,China(No.07-12)
文摘Large earthquakes cause observable changes in the Earth’s gravity field,which have been detected by the Gravity Recovery and Climate Experiment(GRACE).Since most previous studies focus on the detection of near-field gravity effects,this study provides the results from the medium-to far-field gravity changes caused by the 2004 Sumatra-Andaman earthquake that are recorded within GRACE monthly solutions.Utilizing a spherical-earth dislocation model we documented that large-scale signals predominate in the global field of the coseismic gravity changes caused by the earthquake.After removing the near-field effects,the coseismic gravity changes show a negative anomaly feature with an average magnitude of-0.18×10-8 m·s-2 in the region ranging~40°from the epicenter,which is considered as the'medium ffield'in this study.From the GRACE data released by Center for Space Research from August 2002 to December 2008,we retrieved the large-scale gravity changes smoothed with 3000 km Gaussian ffilter.The results show that the coseismic gravity changes detected by GRACE in the medium field have an average of(-0.20±0.06)×10-8 m·s-2,which agrees with the model prediction.The detection confirms that GRACE is sensitive to large-scale medium-field coseismic gravitational effects of mega earthquakes,and also validates the spherical-earth dislocation model in the medium field from the perspective of satellite gravimetry.
基金the National Natural Science Foundation of China (Grant Nos. 40404005 and 40374029)the Excellent Prize of President ScholarshipHundred Talents Program of the Chinese Academy of Sciences
文摘Sumatra-Andaman Large Earthquake on Dec. 26,2004 generated not only the Indian Ocean Tsunami but also the Earth's free oscillations (EFO). The signals of Earth's free oscillations were perfectly re-corded by the superconducting gravimeter C0-32 at Wuhan station in China. After the pre-treatment and spectral analysis on the observational data from Wuhan station,we obtained more than ninety EFO modes including 42 fundamental modes,2 radial modes and 49 harmonic modes. On the basis of the discussions on some observed harmonic modes and abnormal splitting phenomena,we considered that the real rigidity might be lower than the theoretical prediction of PREM model in the inner core and however the anisotropy of compressive wave was brightly higher than the present estimations in the inner core. This suggested that the anisotropy of the inner core could be much more complicated than our present understanding,and there might be some new geophysical phenomena in the formation process of the inner core.
基金Supported by National Key Technologies R&D Program of China (Grant No. 2005DIA3J117)
文摘The Sumatra-Andaman earthquake on December 26, 2004 is the first well recorded gigantic earthquake (moment magnitude MW 9.3) by modern broadband seismic and Global Positioning System networks. The rich seismic and geodetic recordings have documented unprecedented details about the earthquake rupture, coseismic and postseismic deformations. This is a report of detailed images of the rupture process using the first-arriving compressional waves recorded by the China National Digital Seismic Network (CNDSN). An improved imaging condition was employed to account for the sparse distribution of the CNDSN stations. The resulting images are consistent with the major rupture features reported by previous seismic and geodetic studies. It is found that the earthquake rupture initiated at offshore of northwestern Sumatra and propagated in the north northwest direction at a speed of 2.7 ± 0.2 km/s. The rupture continued for at least 420 s and extended about 1200-1300 km along the Andaman trough with two bursts of seismic energy.
基金supported by the grant of the Department of Science and Technology,Govt.of India,New Delhi
文摘We address the role of the concave and convex arcs （as observed from the subducting plate） on the deformation occurring along the Myanmar-Andaman-Sumatra margin. We categorize the pre- and post-seismic deformations of the lithosphere using earthquake database occurring either prior to 26th December 2004 Mw 9.3 off-Sumatra mega-event or after the incidence. Analysis under pre-seismic domain shows that area near Sumatra records highest seismicity, which largely drops in the area past the North Andaman, and further increases towards north. Shallowest depth and mini- mum dip of the subducting lithosphere is recorded at the central segment where the arc transformed into concave shape. The annual moment energy release during earthquake decreases to more than two orders of magnitude past the North Andaman towards north under post-seismic deformation phase. Higher depths of continuity of events are presumably associated with more dipping Benioff zones in both the Indo-Myanmar and Andaman-Nicobar convex arcs. These observations obviously account for tectonic subdivision of the margin near concave shape arc around the central part. Absence of vol- canism, presence of splay faults in the back-arc, sharp reduction in seismicity near central segment are interpreted to be caused by major tectonic impact of the NNE-ward converging buoyant Ninety-east Ridge against the Asian Plate. Shallowest dip, small elastic thickness, weak converging Indian litho- sphere, and evidences of series of en-echelon blocks off the eastern side of the broken northern Ninety- east Ridge might be incapable of generating great earthquake in this area.
基金supported by the Special Fund of Fundamental Scientific Research Business Expense for Higher School of Central Government(Projects for creation teams ZY20110101)NSFC 41090294talent selection and training plan project of Hebei university
文摘We analyze co-seismic displacement field of the 26 December 2004, giant Sumatra–Andaman earthquake derived from Global Position System observations,geological vertical measurement of coral head, and pivot line observed through remote sensing. Using the co-seismic displacement field and AK135 spherical layered Earth model, we invert co-seismic slip distribution along the seismic fault. We also search the best fault geometry model to fit the observed data. Assuming that the dip angle linearly increases in downward direction, the postfit residual variation of the inversed geometry model with dip angles linearly changing along fault strike are plotted. The geometry model with local minimum misfits is the one with dip angle linearly increasing along strike from 4.3oin top southernmost patch to 4.5oin top northernmost path and dip angle linearly increased. By using the fault shape and geodetic co-seismic data, we estimate the slip distribution on the curved fault. Our result shows that the earthquake ruptured ＊200-km width down to a depth of about 60 km.0.5–12.5 m of thrust slip is resolved with the largest slip centered around the central section of the rupture zone78N–108N in latitude. The estimated seismic moment is8.2 9 1022 N m, which is larger than estimation from the centroid moment magnitude（4.0 9 1022 N m）, and smaller than estimation from normal-mode oscillation data modeling（1.0 9 1023 N m）.
基金The IRIS DMS is funded through the National Science Foundation and specifically the GEO Directorate through the Instrumentation and Facilities Program of the National Science Foundation under Cooperative Agreement EAR-0004370
