An earthquake of Ms 8 struck Wenchuan County, western Sichuan, China, on May 12^th, 2008 and resulted in long surface ruptures （〉300 km）. The first-hand observations about the surface ruptures produced by the earth...An earthquake of Ms 8 struck Wenchuan County, western Sichuan, China, on May 12^th, 2008 and resulted in long surface ruptures （〉300 km）. The first-hand observations about the surface ruptures produced by the earthquake in the worst-hit areas of Yingxiu, Beichuan and Qingchuan, ascertained that the causative structure of the earthquake was in the central fault zones of the Longmenshan tectonic belt. Average co-seismic vertical displacements along the individual fault of the Yingxiu-Beiehuan rupture zone reach 2.514 m and the cumulative vertical displacements across the central and frontal Longmenshan fault belt is about 5-6 m. The surface rupture strength was reduced from north of Beichuan to Qingchuan County and shows 2-3 m dextral strike-slip component. The Wenchuan thrust-faulting earthquake is a manifestation of eastward growth of the Tibetan Plateau under the action of continuous convergence of the Indian and Eurasian continents.展开更多
A wide band (1000 - 0.001 Hz) magnetotelluric study has been taken up in the Bhuj earthquake epicentral zone and 21 sites have been occupied along three profiles during March-April 2001 to understand the deep structur...A wide band (1000 - 0.001 Hz) magnetotelluric study has been taken up in the Bhuj earthquake epicentral zone and 21 sites have been occupied along three profiles during March-April 2001 to understand the deep structure of the region. In addition the region surrounding Bhuj has been probed earlier with number of MT profiles and the subsurface structure is well constrained from hydrocarbon exploration point of view besides seismotectonic studies. In the present study, the results obtained along 130 km long profile from Mundra to Rapar oriented in NE-SW direction passing through the epicenter are presented considering these two databases. The subsurface structure has shown interesting correlation with the surface deformations, a new basement configuration and associated seismotectonics of the region. Our main result is relating the basement configuration and surface ruptures.展开更多
文摘An earthquake of Ms 8 struck Wenchuan County, western Sichuan, China, on May 12^th, 2008 and resulted in long surface ruptures （〉300 km）. The first-hand observations about the surface ruptures produced by the earthquake in the worst-hit areas of Yingxiu, Beichuan and Qingchuan, ascertained that the causative structure of the earthquake was in the central fault zones of the Longmenshan tectonic belt. Average co-seismic vertical displacements along the individual fault of the Yingxiu-Beiehuan rupture zone reach 2.514 m and the cumulative vertical displacements across the central and frontal Longmenshan fault belt is about 5-6 m. The surface rupture strength was reduced from north of Beichuan to Qingchuan County and shows 2-3 m dextral strike-slip component. The Wenchuan thrust-faulting earthquake is a manifestation of eastward growth of the Tibetan Plateau under the action of continuous convergence of the Indian and Eurasian continents.
文摘A wide band (1000 - 0.001 Hz) magnetotelluric study has been taken up in the Bhuj earthquake epicentral zone and 21 sites have been occupied along three profiles during March-April 2001 to understand the deep structure of the region. In addition the region surrounding Bhuj has been probed earlier with number of MT profiles and the subsurface structure is well constrained from hydrocarbon exploration point of view besides seismotectonic studies. In the present study, the results obtained along 130 km long profile from Mundra to Rapar oriented in NE-SW direction passing through the epicenter are presented considering these two databases. The subsurface structure has shown interesting correlation with the surface deformations, a new basement configuration and associated seismotectonics of the region. Our main result is relating the basement configuration and surface ruptures.
