Eastern Himalayan Syntaxis consists of Namche Barwa and Assam syntaxis. Namche Barwa, located at south east edge Tibet plateau, is the least\|known place for geologist, because there are thick trees and more rains as ...Eastern Himalayan Syntaxis consists of Namche Barwa and Assam syntaxis. Namche Barwa, located at south east edge Tibet plateau, is the least\|known place for geologist, because there are thick trees and more rains as well as difficult traffic condition, but Namche Barwa syntaxis is very important to Himalayan and Tibet plateau research. A Big Bend of Yalu Tsangpo and the deepest Grand Canyon in the word developed in Namche Barwa region. From core to surrounding Namche Barwa syntaxis may be divided into Himalayan,Yalu Tsangpo as well as Gangdise three tectonic units and three boundary fault zone.The core of syntaxis is Himalayan unit with Zircon U\|Pb age 1312±6Ma which is correlated to High Himalayan unit in central Himalayan, major rocks of core are garnet\|plagioclase gneiss and hornblende\|plagioclase gneiss as well as layered migmatites, some lens or band of high pressure granulite,garnet\|clinopyroxenite(ecologite) and rare marbles also exist in this unit. Research result indicates that rock of core may have experienced poly\|phase metamorphism and deformation, from early granulite or eclogite facies to late amphibole face.展开更多
The 2017 Milin earthquake occurred near Namche Barwa on the southeastern Tibetan Plateau.This research employed Sentinel-1 imagery to capture the corresponding coseismic deformation field and adopted a joint inversion...The 2017 Milin earthquake occurred near Namche Barwa on the southeastern Tibetan Plateau.This research employed Sentinel-1 imagery to capture the corresponding coseismic deformation field and adopted a joint inversion approach using geodetic measurements and teleseismic waveform data to assess earthquake mechanics.The coseismic deformation indicated distinct differential movements,indicating a thrust movement of this fault with uplift in northeast side.The calculated seismic moment magnitude was Mw 6.5,with the fault striking of 305°and a dip angle of 72°The earthquake hypocenter was located at a depth of approximately 10 km,and the maximum fault slip was approximately 1.08 m.The event was attributed to the northwestern segment of the Xixingla fault.Numerical simulations indicated a peak ground velocity of approximately 0.3 m/s.The northwestern segment of the Xixingla fault was identified as the seismogenic fault of the event.Furthermore,the Coulomb stress analysis indicates that the earthquake induced stress loading on the Dongju-Milin and Jiali faults.The surface strain analysis reveals a region of high strain adjacent to the fault.The 2017 Milin earthquake occurred because the Xixingla fault underwent predominantly thrust-type sliding due to the continuous tectonic stress induced within the Tibetan Plateau.Notably,the middle segment of the Xixingla fault currently experiences relatively low seismic activity and is in a state of stress and strain accumulation.Thus,strong earthquakes may occur within the middle segment of the Xixingla fault.展开更多
文摘Eastern Himalayan Syntaxis consists of Namche Barwa and Assam syntaxis. Namche Barwa, located at south east edge Tibet plateau, is the least\|known place for geologist, because there are thick trees and more rains as well as difficult traffic condition, but Namche Barwa syntaxis is very important to Himalayan and Tibet plateau research. A Big Bend of Yalu Tsangpo and the deepest Grand Canyon in the word developed in Namche Barwa region. From core to surrounding Namche Barwa syntaxis may be divided into Himalayan,Yalu Tsangpo as well as Gangdise three tectonic units and three boundary fault zone.The core of syntaxis is Himalayan unit with Zircon U\|Pb age 1312±6Ma which is correlated to High Himalayan unit in central Himalayan, major rocks of core are garnet\|plagioclase gneiss and hornblende\|plagioclase gneiss as well as layered migmatites, some lens or band of high pressure granulite,garnet\|clinopyroxenite(ecologite) and rare marbles also exist in this unit. Research result indicates that rock of core may have experienced poly\|phase metamorphism and deformation, from early granulite or eclogite facies to late amphibole face.
基金the National Natural Science Foundation of China BSCTPES project(41988101)the National Natural Science Foundation of China(92355002).
文摘The 2017 Milin earthquake occurred near Namche Barwa on the southeastern Tibetan Plateau.This research employed Sentinel-1 imagery to capture the corresponding coseismic deformation field and adopted a joint inversion approach using geodetic measurements and teleseismic waveform data to assess earthquake mechanics.The coseismic deformation indicated distinct differential movements,indicating a thrust movement of this fault with uplift in northeast side.The calculated seismic moment magnitude was Mw 6.5,with the fault striking of 305°and a dip angle of 72°The earthquake hypocenter was located at a depth of approximately 10 km,and the maximum fault slip was approximately 1.08 m.The event was attributed to the northwestern segment of the Xixingla fault.Numerical simulations indicated a peak ground velocity of approximately 0.3 m/s.The northwestern segment of the Xixingla fault was identified as the seismogenic fault of the event.Furthermore,the Coulomb stress analysis indicates that the earthquake induced stress loading on the Dongju-Milin and Jiali faults.The surface strain analysis reveals a region of high strain adjacent to the fault.The 2017 Milin earthquake occurred because the Xixingla fault underwent predominantly thrust-type sliding due to the continuous tectonic stress induced within the Tibetan Plateau.Notably,the middle segment of the Xixingla fault currently experiences relatively low seismic activity and is in a state of stress and strain accumulation.Thus,strong earthquakes may occur within the middle segment of the Xixingla fault.
