Two rupture zones of Wenchuan earthquake have been successfully located by an offset-tracking procedure of ENVISAT ASAR amplitude images.Accuracy of offset-tracking strongly depends on the quality of image coregistrat...Two rupture zones of Wenchuan earthquake have been successfully located by an offset-tracking procedure of ENVISAT ASAR amplitude images.Accuracy of offset-tracking strongly depends on the quality of image coregistration.In order to remove noise caused by coregistration,a combined filter method is proposed to remove noise of estimated offsets.In addition,Kriging interpolation is applied to smooth the azimuth displacement offset map.The displacement offset maps of azimuth and range show that about 245 km and 60 km in length along Beichuan-Yingxiu fault and Guanxian-Jiangyou fault were ruptured by Wenchuan earthquake,respectively.The result of offset-tracking is validated by field observations of China Earthquake Administration.展开更多
The 2016 MW7.8 Kaikoura earthquake struck the northern part of south Island,New Zealand,within the active and complex Australia-Pacific plate boundary system.Firstly,we used the InSAR method to obtain coseismic LOS de...The 2016 MW7.8 Kaikoura earthquake struck the northern part of south Island,New Zealand,within the active and complex Australia-Pacific plate boundary system.Firstly,we used the InSAR method to obtain coseismic LOS deformation fields based on SAR images and applied offset tracking methods to obtain offset measurements based on optical satellite images.The maximum displacement of about 6 m is detected in the direction away from the satellite on the south-west side and also towards the satellite on the north-east side.The 3D deformation field is then resolved by the combination of these measurements with a least-square solve method,and comparisons with 3 components of GPS stations show good consistency.Despite complex features demonstrated in the 3D deformation field,there are still clear spatial correlations between surface deformation and faults distribution.It reveals that more than ten faults were ruptured during the earthquake,including some faults were previously understudies for their tectonic activities.The maximum horizontal deformation of about 10 m occurs along the Kekerengu fault with the vertical deformation up to 2 m.The 3D deformation shows that the mainshock is a multisegments faulting with a rupture process of strike-slip,compression,transpressional rupture and strike-slip in space along the NE direction.展开更多
基金sponsored by the Special Item of Professional Fund for Basic Scientific Research of Chinese Central-Level Public-Welfare College/Institute from Chinese Finance Department (ZDJ2009-36)National Natural Science Foundation of China (40774023)+1 种基金National 863 Program of China (2006AA12Z150)the project Dragon 2 (5343)
文摘Two rupture zones of Wenchuan earthquake have been successfully located by an offset-tracking procedure of ENVISAT ASAR amplitude images.Accuracy of offset-tracking strongly depends on the quality of image coregistration.In order to remove noise caused by coregistration,a combined filter method is proposed to remove noise of estimated offsets.In addition,Kriging interpolation is applied to smooth the azimuth displacement offset map.The displacement offset maps of azimuth and range show that about 245 km and 60 km in length along Beichuan-Yingxiu fault and Guanxian-Jiangyou fault were ruptured by Wenchuan earthquake,respectively.The result of offset-tracking is validated by field observations of China Earthquake Administration.
基金co-supported by the National Key Research and Development Program of China(Grant No.2019YFC1509204)the National Nonprofit Fundamental Research Grant of China,Institute of Geology,China Earthquake Administration(Grant No.IGCEA2005 and No.IGCEA2014)the National Science Foundation of China(Grant No.41631073)
文摘The 2016 MW7.8 Kaikoura earthquake struck the northern part of south Island,New Zealand,within the active and complex Australia-Pacific plate boundary system.Firstly,we used the InSAR method to obtain coseismic LOS deformation fields based on SAR images and applied offset tracking methods to obtain offset measurements based on optical satellite images.The maximum displacement of about 6 m is detected in the direction away from the satellite on the south-west side and also towards the satellite on the north-east side.The 3D deformation field is then resolved by the combination of these measurements with a least-square solve method,and comparisons with 3 components of GPS stations show good consistency.Despite complex features demonstrated in the 3D deformation field,there are still clear spatial correlations between surface deformation and faults distribution.It reveals that more than ten faults were ruptured during the earthquake,including some faults were previously understudies for their tectonic activities.The maximum horizontal deformation of about 10 m occurs along the Kekerengu fault with the vertical deformation up to 2 m.The 3D deformation shows that the mainshock is a multisegments faulting with a rupture process of strike-slip,compression,transpressional rupture and strike-slip in space along the NE direction.
