The 2010 Mw 6.9 Yushu earthquake produced a ~33-km-long co-seismic surface rupture zone along the pre-existing active Yushu Fault on China’s central Tibetan Plateau. Sand boils occurred along the tension cracks of th...The 2010 Mw 6.9 Yushu earthquake produced a ~33-km-long co-seismic surface rupture zone along the pre-existing active Yushu Fault on China’s central Tibetan Plateau. Sand boils occurred along the tension cracks of the co-seismic surface rupture zone, and locally spouted up above the ground to coat the top of limestone blocks that had slid down from an adjacent ~300-m-high mountain slope. Based on our observations, the relations between the arrival times of P- and S-waves at the sand-boil location and the seismic rupture velocity, we conclude that 1) the sand boils occurred at least 18.24 s after the main shock;2) it took at least 4.09 - 9.79 s after the formation of co-seismic surface rupture to generate liquefaction at the sand-boil location;3) the spouting height of sand boils was at least 65 cm. Our findings help to clarify the relationships between the timing of lique-faction and the spouting height of sand boils during a large-magnitude earthquake.展开更多
Coulomb stress accumulation and releasing history and its relationship with the occur- rence of strong historical earthquakes could deepen our understanding of the occurrence pattern of strong earthquakes and hence it...Coulomb stress accumulation and releasing history and its relationship with the occur- rence of strong historical earthquakes could deepen our understanding of the occurrence pattern of strong earthquakes and hence its seismic potential in future. The sinistral strike-slip Xianshuihe- Xiaojiang fault zone （XXFS） is one of the most dangerous fault zones in China, extending 1 500-km- long from the central Tibetan Plateau to the Red River fault zone. There are 35 M≥6.5 historical earth- quakes occurred since 1327, hence it is an ideal site for studying the Coulomb stress evolution history and its relationship with the occurrences of strong earthquakes. In this study, we evaluated the Cou- lomb stress change history along the XXFS by synthesizing fault geometry, GPS data and historical earthquakes. Coulomb stress change history also revealed different patterns of historical earthquakes on different segments of the XXFS, such as characteristic recurrence intervals along the Salaha-Moxi fault and super-cycles along the Xianshuihe fault. Based on the occurrence pattern of past historical earthquakes and current Coulomb stress field obtained in this study, we suggest positive ACFS and hence high seismic potential along the Salaha-Moxi fault and the Anninghe fault.展开更多
In this paper, we focus on the characteristics of the landslides developed in the epicentral area of AD 1556 M^8.5 Huaxian Earthquake, and discuss their relations to the active normal faults in the SE Weihe Graben, Ce...In this paper, we focus on the characteristics of the landslides developed in the epicentral area of AD 1556 M^8.5 Huaxian Earthquake, and discuss their relations to the active normal faults in the SE Weihe Graben, Central China. The results from analyzing high-resolution remote-sensing imagery and digital elevation models（DEMs）, in combination with field survey, demonstrate that：（i） the landslides observed in the study area range from small-scale debris/rock falls to large-scale rock avalanches;（ii） the landslides are mostly developed upon steep slopes of ≥30°; and（iii） the step-like normal-fault scarps along the range-fronts of the Huashan Mountains as well as the thick loess sediments in the Weinan area may facilitate the occurrence of large landslides. The results presented in this study would be helpful to assess the potential landslide hazards in densely-populated areas affected by active normal faulting.展开更多
文摘The 2010 Mw 6.9 Yushu earthquake produced a ~33-km-long co-seismic surface rupture zone along the pre-existing active Yushu Fault on China’s central Tibetan Plateau. Sand boils occurred along the tension cracks of the co-seismic surface rupture zone, and locally spouted up above the ground to coat the top of limestone blocks that had slid down from an adjacent ~300-m-high mountain slope. Based on our observations, the relations between the arrival times of P- and S-waves at the sand-boil location and the seismic rupture velocity, we conclude that 1) the sand boils occurred at least 18.24 s after the main shock;2) it took at least 4.09 - 9.79 s after the formation of co-seismic surface rupture to generate liquefaction at the sand-boil location;3) the spouting height of sand boils was at least 65 cm. Our findings help to clarify the relationships between the timing of lique-faction and the spouting height of sand boils during a large-magnitude earthquake.
基金supported by the Science Project awarded to A. Lin from the Ministry of Education of China (No. 23253002)the Culture, Sports, Science, and Technology of Japan, and China Postdoctoral Science Foundation (No. 2016M591817) to Bing Yan
文摘Coulomb stress accumulation and releasing history and its relationship with the occur- rence of strong historical earthquakes could deepen our understanding of the occurrence pattern of strong earthquakes and hence its seismic potential in future. The sinistral strike-slip Xianshuihe- Xiaojiang fault zone （XXFS） is one of the most dangerous fault zones in China, extending 1 500-km- long from the central Tibetan Plateau to the Red River fault zone. There are 35 M≥6.5 historical earth- quakes occurred since 1327, hence it is an ideal site for studying the Coulomb stress evolution history and its relationship with the occurrences of strong earthquakes. In this study, we evaluated the Cou- lomb stress change history along the XXFS by synthesizing fault geometry, GPS data and historical earthquakes. Coulomb stress change history also revealed different patterns of historical earthquakes on different segments of the XXFS, such as characteristic recurrence intervals along the Salaha-Moxi fault and super-cycles along the Xianshuihe fault. Based on the occurrence pattern of past historical earthquakes and current Coulomb stress field obtained in this study, we suggest positive ACFS and hence high seismic potential along the Salaha-Moxi fault and the Anninghe fault.
基金supported by the National Natural Science Foundation of China (No. 41502203)the Scientific Research Foundation for Returned Overseas Scholars of China (awarded to G. Rao)+1 种基金the Natural Science Foundation of Zhejiang Province (No. LY15D02001)a Science Project (No. 23253002)from the Ministry of Education, Culture, Sports, Science and Technology of Japan
文摘In this paper, we focus on the characteristics of the landslides developed in the epicentral area of AD 1556 M^8.5 Huaxian Earthquake, and discuss their relations to the active normal faults in the SE Weihe Graben, Central China. The results from analyzing high-resolution remote-sensing imagery and digital elevation models（DEMs）, in combination with field survey, demonstrate that：（i） the landslides observed in the study area range from small-scale debris/rock falls to large-scale rock avalanches;（ii） the landslides are mostly developed upon steep slopes of ≥30°; and（iii） the step-like normal-fault scarps along the range-fronts of the Huashan Mountains as well as the thick loess sediments in the Weinan area may facilitate the occurrence of large landslides. The results presented in this study would be helpful to assess the potential landslide hazards in densely-populated areas affected by active normal faulting.
