Characteristics of isostatic gravity anomaly in Sichuan-Yunnan region,China

来源 :Geodesy and Geodynamics | 被引量 : 0次 | 上传用户:linlong__
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Sichuan-Yunnan region in China,a tectonic transition belt where earthquakes occurred frequently and intensely,has a distinct variation characteristic of gradient zone of Bouguer gravity anomaly(BGA).Many deep faults and epicenters of severe earthquake scatter along the BGA gradient zones.Here we apply two forward models(Airy model and Vening Meinesz model) of isostatic gravity mechanisms(local versus regional) in this region to calculated the isostatic gravity anomaly(IGA).Afterwards,the relationship between IGA and distribution of faults as well as seismicity is also illustrated.The IGA results show that the two models are similar and most parts of the study area are in an isostatic state.Most featured faults are distributed along the steep anomaly gradient zones;earthquakes tend to occur in the non-isostatic area and steep gradient belt of IGA.The distribution of root thickness based on regional mechanism can be associated with the main trend of BGA variation.The regional mechanism is more plausible and closer to the reality because of its relatively further consideration of the horizontal forces derived from adjacent particles in the crust.Then we analyze the effect of isostasy on the tectonic movements and find that the isostatic adjustment is not the main cause of the continuous uplift process of Longmenshan Mountain fault zone,which is due to the Indian-Eurasian continental collision. Sichuan-Yunnan region in China, a tectonic transition belt where earthquakes occurred frequently and intensely, has a distinct variation characteristic of gradient zone of Bouguer gravity anomaly (BGA). Many deep faults and epicenters of severe earthquake scatter along the BGA gradient zones. Here we apply two forward models (Airy model and Vening Meinesz model) of isostatic gravity mechanisms (local versus regional) in this region to calculated the isostatic gravity anomaly (IGA). Afterwards, the relationship between IGA and distribution of faults as well as seismicity is also illustrated. IGA results show that the two models are similar and most parts of the study area are in an isostatic state. Host featured faults are distributed along the steep anomaly gradient zones; earthquakes tend to occur in the non-isostatic area and steep gradient belt of IGA. The distribution of root thickness based on regional mechanism can be associated with the main trend of BGA variation. regional mechanism i s more plausible and closer to the reality because of its relatively more consideration of the horizontal forces derived from adjacent particles in the crust.Then we analyze the effect of isostasy on the tectonic movements and find that the isostatic adjustment is not the main cause of the continuous uplift process of Longmenshan Mountain fault zone, which is due to the Indian-Eurasian continental collision.
其他文献
为探究吕家坨井田地质构造格局,根据钻孔勘探资料,采用分形理论和趋势面分析方法,研究了井田7
为探究吕家坨井田地质构造格局,根据钻孔勘探资料,采用分形理论和趋势面分析方法,研究了井田7
现代数学教学的着力点应放在让每个学生的数学思维能力得到锻炼和发展.在数学教学中,教师不仅要向学生传授最有价值的数学知识,而且要重视开发智力,培养数学思维能力,提高数
在数学课堂上,有效的提问能够激发学生对于数学学习的兴趣,还能促进学生思维能力的发展和进步,在整个初中数学课堂教学过程中,有效提问属于较为重要的一个部分,为了能够有效
为探究吕家坨井田地质构造格局,根据钻孔勘探资料,采用分形理论和趋势面分析方法,研究了井田7
Based on the total electron content(TEC) derived from Global Positioning System(GPS) observations of the Crustal Movement Observation Network of China(CMONOC) a
近年来,我国进入了社会经济发展的新时期,我国的基础教育课程也在进行新的改革,高中化学实验教学可以有效的提升学生的理解能力,通过这种方式可以让学生更好的学习化学.本文
Temporal and spatial variation of ionosphere can influence our daily communication activities.By solving the one-year global positioning system(GPS) data of Sha
为探究吕家坨井田地质构造格局,根据钻孔勘探资料,采用分形理论和趋势面分析方法,研究了井田7
操作活动符合小学生心理特点和认知水平,有助于帮助学生理解和掌握抽象的数学知识.本文结合自己的两个教学案例,具体阐述动手操作在低年级的数学教学中应用.