The deep reason of severe disaster weather with the relationship among the earth nutation,rotation and atmospheric change is explored based on the effective results about the disaster weather prediction of the long te...The deep reason of severe disaster weather with the relationship among the earth nutation,rotation and atmospheric change is explored based on the effective results about the disaster weather prediction of the long term made by the variation of the earth rotation in near 10 years. It is discussed the relationship between the subtropical anticyclone and subtropical easterlies to aim at the problem of high temperature and drought in the globe,further more,the comparison analysis has been made to the earth nutation and the variation of rotation. The research results show that the reasons of severe disaster weather not only are due to atmosphere itself,but have some variation information of earth movement which could be used for the weather forecast.展开更多
Urban geo_environment mainly concerns those regards in and around a city,such as the movement of earth crust and earth surface,conditions of hydrology,geology,geography and meteorology.The relevant studies on geo_disa...Urban geo_environment mainly concerns those regards in and around a city,such as the movement of earth crust and earth surface,conditions of hydrology,geology,geography and meteorology.The relevant studies on geo_disaster reduction and the influences resulted from human activities on the geo_environment are included as well.It is stressed in the paper that geo_environmental protection and management are of significance to the sustainable development for Chinese cities.展开更多
Fault structures in the Litang-Batang region of West Sichuan are mainly sub-longitudinal and a set of NNE- and NW-trending conjugate shear fracture zones is developed. In this paper, emphasis is put on explaining the ...Fault structures in the Litang-Batang region of West Sichuan are mainly sub-longitudinal and a set of NNE- and NW-trending conjugate shear fracture zones is developed. In this paper, emphasis is put on explaining the movement patterns along the fault structures in the region since the late Pleistocene-Holocene on the basis of detailed interpretation of TM satellite images and aero-photos in geomorphologic aspect of active structures. The sub-latitudinal shortening rate along the sub-longitudinal Jinshajiang fault zone is determined to be 2～3mm/a since the late Quaternary, the horizontal dextral slip movement rate along the NNE-trending Batang fault is 1.3～2.7mm/a on average, and the horizontal sinistral slip movement rate along the NW-trending Litang fault is 2.6～4.4 mm/a on average. The general status of the recent crustal movement in the region and the regularities of block motion caused by it are analyzed in combination with data of geophysical fields, focal mechanism solutions and GPS measurements. The occurrence of the 1989 Batang M6.2～6.7 earthquake swarm is suggested to be the result of tensional rupture along the sub-latitudinal normal fault derived from the conjugate shearing along the NNE-trending Batang and the NW-trending Litang faults. It reveals a typical seismic case produced by normal faulting in a compressional tectonic environment.展开更多
Based on their Euler poles, we calculated the relative velocities between every two plates in the typical global plate motion models, respectively, and estimated the area change along these boundaries. In our calculat...Based on their Euler poles, we calculated the relative velocities between every two plates in the typical global plate motion models, respectively, and estimated the area change along these boundaries. In our calculations, plates on both sides accommodated area changes depending on the boundary types： extensional, convergent or transform, so we can estimate area change of each plate and then globally. Our preliminary results show that the area of the southern hemisphere increased while that of the northern hemisphere decreased over the past I million years, and global area has increased by 26,000km^2 to 36,000km^2, which corresponds to the 160m - 250m increment on the Earth＇s radius if all these area increments are attributed to Earth＇s expansion. Taking the NUVEL-1 model as an example, of the 14 plates in this model, 11 are decreasing, but the global area has increased because of the larger increment amount from Africa, North America and Antarctica. Finally, we also discussed factors affecting the global area change such as subduction zone retreating and back-arc spreading.展开更多
基金supported by National Natural Science Foundation of China through Grant( 60674074 )the foundation projects of 2008 LASW-B11,GYHY(QX)2007-6-26,GYHY(QX)2007-6-2, IHR2007K02,FiDAF-2-01, BJG200801,2007AA061901,QD62,KF(2006)11
文摘The deep reason of severe disaster weather with the relationship among the earth nutation,rotation and atmospheric change is explored based on the effective results about the disaster weather prediction of the long term made by the variation of the earth rotation in near 10 years. It is discussed the relationship between the subtropical anticyclone and subtropical easterlies to aim at the problem of high temperature and drought in the globe,further more,the comparison analysis has been made to the earth nutation and the variation of rotation. The research results show that the reasons of severe disaster weather not only are due to atmosphere itself,but have some variation information of earth movement which could be used for the weather forecast.
文摘Urban geo_environment mainly concerns those regards in and around a city,such as the movement of earth crust and earth surface,conditions of hydrology,geology,geography and meteorology.The relevant studies on geo_disaster reduction and the influences resulted from human activities on the geo_environment are included as well.It is stressed in the paper that geo_environmental protection and management are of significance to the sustainable development for Chinese cities.
文摘Fault structures in the Litang-Batang region of West Sichuan are mainly sub-longitudinal and a set of NNE- and NW-trending conjugate shear fracture zones is developed. In this paper, emphasis is put on explaining the movement patterns along the fault structures in the region since the late Pleistocene-Holocene on the basis of detailed interpretation of TM satellite images and aero-photos in geomorphologic aspect of active structures. The sub-latitudinal shortening rate along the sub-longitudinal Jinshajiang fault zone is determined to be 2～3mm/a since the late Quaternary, the horizontal dextral slip movement rate along the NNE-trending Batang fault is 1.3～2.7mm/a on average, and the horizontal sinistral slip movement rate along the NW-trending Litang fault is 2.6～4.4 mm/a on average. The general status of the recent crustal movement in the region and the regularities of block motion caused by it are analyzed in combination with data of geophysical fields, focal mechanism solutions and GPS measurements. The occurrence of the 1989 Batang M6.2～6.7 earthquake swarm is suggested to be the result of tensional rupture along the sub-latitudinal normal fault derived from the conjugate shearing along the NNE-trending Batang and the NW-trending Litang faults. It reveals a typical seismic case produced by normal faulting in a compressional tectonic environment.
基金sponsored by the National Natural Science Foundation (40574047),China
文摘Based on their Euler poles, we calculated the relative velocities between every two plates in the typical global plate motion models, respectively, and estimated the area change along these boundaries. In our calculations, plates on both sides accommodated area changes depending on the boundary types： extensional, convergent or transform, so we can estimate area change of each plate and then globally. Our preliminary results show that the area of the southern hemisphere increased while that of the northern hemisphere decreased over the past I million years, and global area has increased by 26,000km^2 to 36,000km^2, which corresponds to the 160m - 250m increment on the Earth＇s radius if all these area increments are attributed to Earth＇s expansion. Taking the NUVEL-1 model as an example, of the 14 plates in this model, 11 are decreasing, but the global area has increased because of the larger increment amount from Africa, North America and Antarctica. Finally, we also discussed factors affecting the global area change such as subduction zone retreating and back-arc spreading.
