TY - JOUR

T1 - The 29 March 2017 Yuzhno‐Ozernovskoe Kamchatka Earthquake

T2 - Fault Activity in An Extension of the East Kamchatka Fault Zone as Constrained by InSAR Observations

AU - Vassileva, Magdalena S.

AU - Motagh, Mahdi

AU - Walter, Thomas R.

AU - Wetzel, Hans Ulrich

AU - Senyukov, Sergey L.

N1 - Funding information: The authors thank the Japanese and European Space Agency for Advanced Land Observation Satellite (ALOS)-2 and Sentinel-1 satellite radar data, respectively, and all the seismological agencies (Global Centroid Moment Tensor Project, the U.S. Geological Survey, GEOFOrschungsNetz, National Institute of Geophysics and Volcanology, Global Network of Broadband Seismic Stations, and Seismological Data Information System of Kamchatka Branch of Geophysical Survey of Russian Academy of Sciences Earthquakes Catalogue for Kamchatka and the Commander Islands [1962–present]) for the earthquake mechanism parameter values used to set up the initial model parameter intervals. The authors thank the Geological Research Institute of the Ministry of Natural Resources and Ecology of the Russian Federation (Federal Agency of Mineral Resources, Russia) for the geological data. The authors thank Harris Geospatial Solutions, Inc., and sarmap for developing and providing SARscape version 5.4.1 (v.5.4.1) module in the Environment for Visualizing Images (ENVI) platform used to perform the main processing steps. The authors thank QGIS project for providing the geographic information system tool used in this work.

PY - 2020

Y1 - 2020

N2 - Recent earthquakes off the northeastern Kamchatka coast reveal that this region is seismically active, although details of the locations and complexity of the fault system are lacking. The northern part of Kamchatka has poor coverage by permanent seismic stations and ground geodetic instruments. Here, we exploit the Differential Interferometric Synthetic Aperture Radar (DInSAR) technique to characterize the fault geometry and kinematics associated with the 29 March 2017 Mw 6.6 Yuzhno-Ozernovskoe earthquake. The aim is to con-tribute to identifying the active fault branches and to better understanding the complex tectonic regime in this region using the DInSAR technique, which has never before been applied to the analysis of coseismic offsets in Kamchatka.We produced coseismic deformation maps using Advanced Land Observation Satellite-2 ascending and descending and Sentinel-1A descending Synthetic Aperture Radar (SAR) scenes and detected a predominant uplift up to 20 cm and a westward motion of approximately 7 cm near the shoreline. We jointly inverted the three geodetic datasets using elastic half-space fault modeling to retrieve source geometry and fault kinematics. The best-fit solution for the nonlinear inversion suggests a north–west-dipping oblique reverse fault with right-lateral rupture.The model fault geometry is not only generally consistent with the seismic data but also reveals that a hitherto unknown fault was ruptured. The identified fault structure is interpreted as the northern extension of the east Kamchatka fault zone, implying that the region is more complex than previously thought. Important implications arise for the presence of unknown faults at the edges of subduction zones that can generate earthquakes with magnitudes greater than Mw 6.

AB - Recent earthquakes off the northeastern Kamchatka coast reveal that this region is seismically active, although details of the locations and complexity of the fault system are lacking. The northern part of Kamchatka has poor coverage by permanent seismic stations and ground geodetic instruments. Here, we exploit the Differential Interferometric Synthetic Aperture Radar (DInSAR) technique to characterize the fault geometry and kinematics associated with the 29 March 2017 Mw 6.6 Yuzhno-Ozernovskoe earthquake. The aim is to con-tribute to identifying the active fault branches and to better understanding the complex tectonic regime in this region using the DInSAR technique, which has never before been applied to the analysis of coseismic offsets in Kamchatka.We produced coseismic deformation maps using Advanced Land Observation Satellite-2 ascending and descending and Sentinel-1A descending Synthetic Aperture Radar (SAR) scenes and detected a predominant uplift up to 20 cm and a westward motion of approximately 7 cm near the shoreline. We jointly inverted the three geodetic datasets using elastic half-space fault modeling to retrieve source geometry and fault kinematics. The best-fit solution for the nonlinear inversion suggests a north–west-dipping oblique reverse fault with right-lateral rupture.The model fault geometry is not only generally consistent with the seismic data but also reveals that a hitherto unknown fault was ruptured. The identified fault structure is interpreted as the northern extension of the east Kamchatka fault zone, implying that the region is more complex than previously thought. Important implications arise for the presence of unknown faults at the edges of subduction zones that can generate earthquakes with magnitudes greater than Mw 6.

UR - http://www.scopus.com/inward/record.url?scp=85085708497&partnerID=8YFLogxK

U2 - 10.1785/0120190174

DO - 10.1785/0120190174

M3 - Article

AN - SCOPUS:85085708497

VL - 110

SP - 1101

EP - 1114

JO - Bulletin of the Seismological Society of America

JF - Bulletin of the Seismological Society of America

SN - 0037-1106

IS - 3

ER -