Based on field investigation in 1999, two deformational domains with d ifferent dynamics have been distinguished from the Jurassic geological outcrops in the Mohe area of NE China, i.e. northern ductile and southern p...Based on field investigation in 1999, two deformational domains with d ifferent dynamics have been distinguished from the Jurassic geological outcrops in the Mohe area of NE China, i.e. northern ductile and southern plastic-brittl e ones. Their deformational features are stated in this paper. And then, three st ages of structural deformation of the area relative to the late Mesozoic orogeni c processes of Mongolian-Okhotsk orogen are reconstructed as follows, (1) south w ards thrusting in the middle-late Jurassic, (2) eastwards thrusting and strike -s lipping parallel to the orogen in the late Jurassic, and (3) southeastwards thru sting in the early Cretaceous.展开更多
This study presents the changes in lake areas in the Valley of Lakes, the Govi region, southern Mongolia. The recent changes in lake areas show decreases depending on vulnerability of lake basins and response of Govi ...This study presents the changes in lake areas in the Valley of Lakes, the Govi region, southern Mongolia. The recent changes in lake areas show decreases depending on vulnerability of lake basins and response of Govi landscape to the present climatic warming. During the recent 44 - 45 years (from 1970 to 2014 or 2015), modern lakes have encountered the present rapid increase in temperature, water evaporation and drying up that induced the reduction in lake areas in the Valley of Lakes. The finding of the reduction in lake areas is consistent with the trends on increasing in temperature since 1995 and fluctuating precipitation since 1975. Investigations with detailed chronology of lake sediment are needed from the lakes to review a more complete evolution of lake basins during the Late Quaternary paleoclimatic history in Mongolia and Central Asia.展开更多
The studied area consists of 16 counties belonging to 3 provinces or autonomous re-gion, which are Hequ, Baode, Pianguan and Xinxian counties of Shanxi Province; Yulin,Shenmu, Fugu, Hengshan, Jingbian and Dingbian cou...The studied area consists of 16 counties belonging to 3 provinces or autonomous re-gion, which are Hequ, Baode, Pianguan and Xinxian counties of Shanxi Province; Yulin,Shenmu, Fugu, Hengshan, Jingbian and Dingbian counties of Shaanxi Province;Dongsheng, Tuoketuo, Qingshuihe counties and Yijinhuoluo, Dalate, Zhungeer banners展开更多
plane with the strike of 127°, the dip of 79° and the rake of 171°. The rupture process inversion result of MS=7.9 earthquake shows that the total rupture duration is about 37 s, the scalar moment tenso...plane with the strike of 127°, the dip of 79° and the rake of 171°. The rupture process inversion result of MS=7.9 earthquake shows that the total rupture duration is about 37 s, the scalar moment tensor is M0=0.97 × 1020 N·m. Rupture mainly occurred on the shallow area with 110 km long and 30 km wide, the location in which the rupture initiated is not where the main rupture took place, and the area with slip greater than 0.5 m basically lies within 35 km deep middle-crust under the earth surface. The maximum static slip is 3.6 m. There are two distinct areas with slip larger than 2.0 m. We noticed that when the rupture propagated towards northwest and closed to the area around the MS=7.3 hypocenter, the slip decreased rapidly, which may indicate that the rupture process was stopped by barriers. The consistence of spatial distribution of slip on the fault plane with the distribution of aftershocks also supports that the rupture is a heterogeneous process owing to the presence of barriers.展开更多
文摘Based on field investigation in 1999, two deformational domains with d ifferent dynamics have been distinguished from the Jurassic geological outcrops in the Mohe area of NE China, i.e. northern ductile and southern plastic-brittl e ones. Their deformational features are stated in this paper. And then, three st ages of structural deformation of the area relative to the late Mesozoic orogeni c processes of Mongolian-Okhotsk orogen are reconstructed as follows, (1) south w ards thrusting in the middle-late Jurassic, (2) eastwards thrusting and strike -s lipping parallel to the orogen in the late Jurassic, and (3) southeastwards thru sting in the early Cretaceous.
文摘This study presents the changes in lake areas in the Valley of Lakes, the Govi region, southern Mongolia. The recent changes in lake areas show decreases depending on vulnerability of lake basins and response of Govi landscape to the present climatic warming. During the recent 44 - 45 years (from 1970 to 2014 or 2015), modern lakes have encountered the present rapid increase in temperature, water evaporation and drying up that induced the reduction in lake areas in the Valley of Lakes. The finding of the reduction in lake areas is consistent with the trends on increasing in temperature since 1995 and fluctuating precipitation since 1975. Investigations with detailed chronology of lake sediment are needed from the lakes to review a more complete evolution of lake basins during the Late Quaternary paleoclimatic history in Mongolia and Central Asia.
文摘The studied area consists of 16 counties belonging to 3 provinces or autonomous re-gion, which are Hequ, Baode, Pianguan and Xinxian counties of Shanxi Province; Yulin,Shenmu, Fugu, Hengshan, Jingbian and Dingbian counties of Shaanxi Province;Dongsheng, Tuoketuo, Qingshuihe counties and Yijinhuoluo, Dalate, Zhungeer banners
基金The Specialized Funds for National Key Basic Study (G1998040704), the Dual Project of China Earthquake Admini-stration (9691309020301) and National Natural Science Foundation of China (46764010).
文摘plane with the strike of 127°, the dip of 79° and the rake of 171°. The rupture process inversion result of MS=7.9 earthquake shows that the total rupture duration is about 37 s, the scalar moment tensor is M0=0.97 × 1020 N·m. Rupture mainly occurred on the shallow area with 110 km long and 30 km wide, the location in which the rupture initiated is not where the main rupture took place, and the area with slip greater than 0.5 m basically lies within 35 km deep middle-crust under the earth surface. The maximum static slip is 3.6 m. There are two distinct areas with slip larger than 2.0 m. We noticed that when the rupture propagated towards northwest and closed to the area around the MS=7.3 hypocenter, the slip decreased rapidly, which may indicate that the rupture process was stopped by barriers. The consistence of spatial distribution of slip on the fault plane with the distribution of aftershocks also supports that the rupture is a heterogeneous process owing to the presence of barriers.
