By using the USA NCAR / NCEP reanalysis data, the characteristics of climatic elements and the temporal and spatial structures of precipitation in the strong and weak years of the SCS monsoon are analyzed, the mechani...By using the USA NCAR / NCEP reanalysis data, the characteristics of climatic elements and the temporal and spatial structures of precipitation in the strong and weak years of the SCS monsoon are analyzed, the mechanism of the interannual variation of the SCS monsoon is discussed. It is found that the climatic elements in SCS have great differences, and there are great differences in the spatial and temporal structures of the precipitation anomalies between the strong and weak monsoon years. The variation of climatic elements in the south of Indochina Peninsula in April is a good index of the strength of the SCS monsoon. There is a good connection between the SCS monsoon and the sea surface temperature. The SCS monsoon is weak in the EL Nino years, and strong in the La Nina years. The strength of the SCS monsoon depends on the local heating differences between the eastern continent of China and the western Pacific. It depends on the intensity and the position of the western Pacific Subtropical High. The western Pacific Subtropical High is weak and eastward in the strong monsoon years, and the case is reversed in the weak monsoon years.展开更多
Migration of strong earthquakes (M≥7.0) along the North-South Seismic Belt of China since 1500 AD shows three patterns: Approximately equal time and distance interval migration from N to S, varied patterns of migrati...Migration of strong earthquakes (M≥7.0) along the North-South Seismic Belt of China since 1500 AD shows three patterns: Approximately equal time and distance interval migration from N to S, varied patterns of migration from S to N and grouped strong earthquake activity in a certain period over the entire seismic belt. Analysis of strong earthquakes in the past hundred years shows that the seismicity on the North-South Seismic Belt is also associated with strong earthquake activities on the South Asia Seismic Belt which extends from Myanmar to Sumatra, Indonesia. Strong earthquakes on the former belt often lag several months or years behind the quakes occurring on the later belt. So, after the occurrence of the December 26, 2004 M_S8.7 great earthquake off the western coast of Sumatra, Indonesia, the possibility of occurrence of strong earthquakes on the North-South Seismic Belt of China cannot be ignored. The above-mentioned migration characteristics of strong earthquakes are related to the northeastward collision and subduction of the India Plate as well as the interaction between the Qinghai-Xizang (Tibet) Plateau and the stable and hard Ordos and Alashan Massifs at its northeastern margin.展开更多
The vertical deformation gradient can reflect the rate of vertical change in unit distance,and the vertical deformation velocity gradient can reflect the strength of the earth's crust tectonic activities. In this ...The vertical deformation gradient can reflect the rate of vertical change in unit distance,and the vertical deformation velocity gradient can reflect the strength of the earth's crust tectonic activities. In this paper,using long period leveling data combined with GPS data,the vertical deformation gradient values are calculated. Leveling data and GPS data are two different means of monitoring deformation,but the result is approximately the same vertical deformation gradient. The results show that the spatial distribution of the vertical deformation velocity gradient and tectonic distribution has an obvious correlation. The most significant gradient anomalies along the North-South Seismic Belt are Xianshuihe fault, Longmenshan fault and Xiaojiang-Zemuhe fault, while the second gradient anomalies in the northeastern Qinghai-Tibetan plateau are Zhuanglanghe fault and Lenglongling fault. The Menyuan M_S6. 4 earthquake in 2016 occurred in this abnormal area. However,according to the vertical deformation high gradient area distribution,there is also the possibility of an earthquake occurrence in the Tianzhu and Jingtai area.The area of convergence of three major fault zones is the strongest tectonically active region of the North-South Seismic Belt.展开更多
文摘By using the USA NCAR / NCEP reanalysis data, the characteristics of climatic elements and the temporal and spatial structures of precipitation in the strong and weak years of the SCS monsoon are analyzed, the mechanism of the interannual variation of the SCS monsoon is discussed. It is found that the climatic elements in SCS have great differences, and there are great differences in the spatial and temporal structures of the precipitation anomalies between the strong and weak monsoon years. The variation of climatic elements in the south of Indochina Peninsula in April is a good index of the strength of the SCS monsoon. There is a good connection between the SCS monsoon and the sea surface temperature. The SCS monsoon is weak in the EL Nino years, and strong in the La Nina years. The strength of the SCS monsoon depends on the local heating differences between the eastern continent of China and the western Pacific. It depends on the intensity and the position of the western Pacific Subtropical High. The western Pacific Subtropical High is weak and eastward in the strong monsoon years, and the case is reversed in the weak monsoon years.
基金the Major Program of the National Natural Science Foundation of China (Grant No.90202018)the National Natural Science Foundation of China (40572125)+1 种基金the Special Social Commonweal Research Programs of the Ministry of Science and Technology of China (2004DIB3J129)the special programs of China Earthquake Administration
文摘Migration of strong earthquakes (M≥7.0) along the North-South Seismic Belt of China since 1500 AD shows three patterns: Approximately equal time and distance interval migration from N to S, varied patterns of migration from S to N and grouped strong earthquake activity in a certain period over the entire seismic belt. Analysis of strong earthquakes in the past hundred years shows that the seismicity on the North-South Seismic Belt is also associated with strong earthquake activities on the South Asia Seismic Belt which extends from Myanmar to Sumatra, Indonesia. Strong earthquakes on the former belt often lag several months or years behind the quakes occurring on the later belt. So, after the occurrence of the December 26, 2004 M_S8.7 great earthquake off the western coast of Sumatra, Indonesia, the possibility of occurrence of strong earthquakes on the North-South Seismic Belt of China cannot be ignored. The above-mentioned migration characteristics of strong earthquakes are related to the northeastward collision and subduction of the India Plate as well as the interaction between the Qinghai-Xizang (Tibet) Plateau and the stable and hard Ordos and Alashan Massifs at its northeastern margin.
基金jointly funded by the Project of Science for Earthquake Resilience(XH17059)regular projects of Earthquake Monitoring and Prediction(16H38ZX345)
文摘The vertical deformation gradient can reflect the rate of vertical change in unit distance,and the vertical deformation velocity gradient can reflect the strength of the earth's crust tectonic activities. In this paper,using long period leveling data combined with GPS data,the vertical deformation gradient values are calculated. Leveling data and GPS data are two different means of monitoring deformation,but the result is approximately the same vertical deformation gradient. The results show that the spatial distribution of the vertical deformation velocity gradient and tectonic distribution has an obvious correlation. The most significant gradient anomalies along the North-South Seismic Belt are Xianshuihe fault, Longmenshan fault and Xiaojiang-Zemuhe fault, while the second gradient anomalies in the northeastern Qinghai-Tibetan plateau are Zhuanglanghe fault and Lenglongling fault. The Menyuan M_S6. 4 earthquake in 2016 occurred in this abnormal area. However,according to the vertical deformation high gradient area distribution,there is also the possibility of an earthquake occurrence in the Tianzhu and Jingtai area.The area of convergence of three major fault zones is the strongest tectonically active region of the North-South Seismic Belt.
