TY - JOUR
T1 - Coseismic slip of the 2010 Mw 8.8 Great Maule, Chile, earthquake quantified by the inversion of GRACE observations
AU - Wang, Lei
AU - Shum, C. K.
AU - Simons, Frederik J.
AU - Tassara, Andrés
AU - Erkan, Kamil
AU - Jekeli, Christopher
AU - Braun, Alexander
AU - Kuo, Chungyen
AU - Lee, Hyongki
AU - Yuan, Dah Ning
N1 - Funding Information:
This research was supported by the U.S. National Science Foundation under Grants EAR-1013333 and EAR-1014606 , and partially supported under the Chinese Academy of Sciences/SAFEA International Partnership Program for Creative Research Teams . GRACE data products are from NASA via the University of Texas Center for Space Research and JPL-PODAAC. We thank Chen Ji, UCSB, for providing his coseismic model and also his comments and suggestions, which have enhanced the quality of the manuscript. We thank the modelers for providing their coseismic slip models used in the study. We thank the Editor and three anonymous reviewers for providing constructive comments, which resulted in the improvement of the manuscript.
PY - 2012/6/15
Y1 - 2012/6/15
N2 - The 27 February 2010 Mw 8.8 Maule, Chile, earthquake ruptured over 500. km along a mature seismic gap between 34° S and 38° S-the Concepción-Constitución gap, where no large megathrust earthquakes had occurred since the 1835. Mw ~8.5 event. Notable discrepancies exist in slip distribution and moment magnitude estimated by various models inverted using traditional observations such as teleseismic networks, coastal/river markers, tsunami sensors, Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR). We conduct a spatio-spectral localization analysis, based on Slepian basis functions, of data from Gravity Recovery And Climate Experiment (GRACE) to extract coseismic gravity change signals of the Maule earthquake with improved spatial resolution (350. km half-wavelength). Our results reveal discernible differences in the average slip between the GRACE observation and predictions from various coseismic models. The sensitivity analysis reveals that GRACE observation is sensitive to the size of the fault, but unable to separate depth and slip. Here we assume the depth of the fault is known, and simultaneously invert for the fault-plane area and the average slip using the simulated annealing algorithm. Our GRACE-inverted fault plane length and width are 429±6. km, 146±5. km, respectively. The estimated slip is 8.1±1.2. m, indicating that most of the strain accumulated since 1835 in the Concepción-Constitución gap was released by the 2010 Maule earthquake.
AB - The 27 February 2010 Mw 8.8 Maule, Chile, earthquake ruptured over 500. km along a mature seismic gap between 34° S and 38° S-the Concepción-Constitución gap, where no large megathrust earthquakes had occurred since the 1835. Mw ~8.5 event. Notable discrepancies exist in slip distribution and moment magnitude estimated by various models inverted using traditional observations such as teleseismic networks, coastal/river markers, tsunami sensors, Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR). We conduct a spatio-spectral localization analysis, based on Slepian basis functions, of data from Gravity Recovery And Climate Experiment (GRACE) to extract coseismic gravity change signals of the Maule earthquake with improved spatial resolution (350. km half-wavelength). Our results reveal discernible differences in the average slip between the GRACE observation and predictions from various coseismic models. The sensitivity analysis reveals that GRACE observation is sensitive to the size of the fault, but unable to separate depth and slip. Here we assume the depth of the fault is known, and simultaneously invert for the fault-plane area and the average slip using the simulated annealing algorithm. Our GRACE-inverted fault plane length and width are 429±6. km, 146±5. km, respectively. The estimated slip is 8.1±1.2. m, indicating that most of the strain accumulated since 1835 in the Concepción-Constitución gap was released by the 2010 Maule earthquake.
KW - GRACE
KW - Geodynamics
KW - Maule earthquake
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U2 - 10.1016/j.epsl.2012.04.044
DO - 10.1016/j.epsl.2012.04.044
M3 - Article
AN - SCOPUS:84859602693
SN - 0012-821X
VL - 335-336
SP - 167
EP - 179
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
ER -