针对2013年1月23日辽宁灯塔M_(S)5.1地震,利用引潮力附加构造应力(Additional Tectonic Stress Caused By Tidal Force,ATSCTF)计算模型,计算得到震中位置(41.5°N,123.2°E)在地震前5周以及震后3周(2012年12月16日—2013年2月1...针对2013年1月23日辽宁灯塔M_(S)5.1地震,利用引潮力附加构造应力(Additional Tectonic Stress Caused By Tidal Force,ATSCTF)计算模型,计算得到震中位置(41.5°N,123.2°E)在地震前5周以及震后3周(2012年12月16日—2013年2月15日)的ATSCTF变化。地震发生时,ATSCTF垂直方向分量处于高相位点附近,显示引潮力对本次正断层走滑型地震具有诱发作用。以ATSCTF变化周期的各低相位点时间(2012年12月19日、2013年1月4日、2013年1月18日、2013年2月2日)数据分别为背景,各周期期后数据分别与背景逐日相减,计算研究区(36°N~46°N,118°E~128°E)范围内,National Oceanic and Atmospheric Administration(NOAA)卫星射出长波辐射数据(Outgoing Long Wave Radiation,OLR)在各ATSCTF周期时段分布及其变化。结果显示,无震的ATSCTF变化的A、B、D周期,震中附近OLR无变化;发震的ATSCTF变化的C周期,在空间上,该地区震前OLR仅震中及其南侧区域发生了显著连续升高变化过程,在时间上经历了初始微异常→异常加强→高峰→衰减→发震→平静的演化过程,与岩石应力加载—破裂经历:初始微动破裂→扩张破裂→应力闭锁→地震爆发→平静的力学演化过程中各阶段红外辐射特征一致;显示引潮力对处于临界状态的活动断层具有诱发作用,而OLR是地震构造应力应变过程辐射表征。展开更多
1研究背景将卫星遥感红外资料应用于地震监测,起始于20世纪80年代前苏联科学家。后续国内外学者陆续开展了这方面的研究,提出了涡度、RST、ZS、距平和功率谱等异常提取方法,取得了大量震例和机理方面的研究成果(张元生等,2002;Tramutoli...1研究背景将卫星遥感红外资料应用于地震监测,起始于20世纪80年代前苏联科学家。后续国内外学者陆续开展了这方面的研究,提出了涡度、RST、ZS、距平和功率谱等异常提取方法,取得了大量震例和机理方面的研究成果(张元生等,2002;Tramutoli et al,2005;Ouzounov et al,2007;Freund,2011;Jing et al,2022)。张铁宝等(2016)研究表明,川滇块体东边界带强震前,川滇块体存在显著的超阈值辐射增强异常。利用该地区通过震例总结得到的红外辐射异常特征,持续对川滇块体红外辐射进行了多年跟踪,在2022年9月5日四川泸定M_(S)6.8地震前,川滇块体又再次出现了类似的异常变化。泸定地震发生在川滇块体东边界的鲜水河断裂带磨西段。本研究主要分析泸定地震前红外辐射的异常变化。展开更多
Research on the range anomaly suppression algorithm in laser radar (ladar) range images is significant in the application and development of ladar. But most of existing algorithms cannot protect the edge and linear ...Research on the range anomaly suppression algorithm in laser radar (ladar) range images is significant in the application and development of ladar. But most of existing algorithms cannot protect the edge and linear target well while suppressing the range anomaly. Aiming at this problem, the differences among the edge, linear target, and range anomaly are analyzed and a novel algo- rithm based on neighborhood pixels detection is proposed. Firstly, the range differences between current pixel and its neighborhood pixels are calculated. Then, the number of neighborhood pixels is detected by the range difference threshold. Finally, whether the current pixel is a range anomaly is distinguished by the neighbor- hood pixel number threshold. Experimental results show that the new algorithm not only has a better range anomaly suppression performance and higher efficiency, but also protects the edge and linear target preferably compared with other algorithms.展开更多
Seismic tomography can provide both fine P-wave and S-wave velocity structures of the crust and upper mantle. In addition, with proper computation, Poisson's ratio images from the seismic velocities can be determined...Seismic tomography can provide both fine P-wave and S-wave velocity structures of the crust and upper mantle. In addition, with proper computation, Poisson's ratio images from the seismic velocities can be determined. However, it is unknown whether Poisson's ratio images have any advantages when compared with the P-wave and S-wave velocity images. For the purposes of this study, high- resolution seismic tomography under the eastern part of North China region was used to determine detailed 3-D crustal P- and S-wave seismic velocities structure, as well as Poisson's ratio images. Results of Poisson's ratio imaging show high Poisson's ratio (high-PR) anomalies located in the Hengshan-North Taihang-Zhangjiakou (H-NT-Z) region, demonstrating that Poisson's ratio imaging can provide new geophysical constraints for regional tectonic evolution. The H-NT-Z region shows a prominent and continuous high-PR anomaly in the upper crust. Based on Poisson's ratio images at different depths, we find that this high-PR anomaly is extending down to the middle crust with thickness up to about 26 kin. According to rock physical property measurements and other geological data, this crustal Poisson's ratio anomaly can be explained by Mesozoic partial melting of the upper mantle and basaltic magma underplating related to the lithospheric thinning of the North China craton.展开更多
基金地震数值预测联合实验室开放基金项目(2020LNEF03)APSCO Earthquake Research Project PhaseⅡ:Integrating Satellite and Ground Observations for Earthquake Signatures and Precursors(WX0519502)。
文摘针对2013年1月23日辽宁灯塔M_(S)5.1地震,利用引潮力附加构造应力(Additional Tectonic Stress Caused By Tidal Force,ATSCTF)计算模型,计算得到震中位置(41.5°N,123.2°E)在地震前5周以及震后3周(2012年12月16日—2013年2月15日)的ATSCTF变化。地震发生时,ATSCTF垂直方向分量处于高相位点附近,显示引潮力对本次正断层走滑型地震具有诱发作用。以ATSCTF变化周期的各低相位点时间(2012年12月19日、2013年1月4日、2013年1月18日、2013年2月2日)数据分别为背景,各周期期后数据分别与背景逐日相减,计算研究区(36°N~46°N,118°E~128°E)范围内,National Oceanic and Atmospheric Administration(NOAA)卫星射出长波辐射数据(Outgoing Long Wave Radiation,OLR)在各ATSCTF周期时段分布及其变化。结果显示,无震的ATSCTF变化的A、B、D周期,震中附近OLR无变化;发震的ATSCTF变化的C周期,在空间上,该地区震前OLR仅震中及其南侧区域发生了显著连续升高变化过程,在时间上经历了初始微异常→异常加强→高峰→衰减→发震→平静的演化过程,与岩石应力加载—破裂经历:初始微动破裂→扩张破裂→应力闭锁→地震爆发→平静的力学演化过程中各阶段红外辐射特征一致;显示引潮力对处于临界状态的活动断层具有诱发作用,而OLR是地震构造应力应变过程辐射表征。
文摘1研究背景将卫星遥感红外资料应用于地震监测,起始于20世纪80年代前苏联科学家。后续国内外学者陆续开展了这方面的研究,提出了涡度、RST、ZS、距平和功率谱等异常提取方法,取得了大量震例和机理方面的研究成果(张元生等,2002;Tramutoli et al,2005;Ouzounov et al,2007;Freund,2011;Jing et al,2022)。张铁宝等(2016)研究表明,川滇块体东边界带强震前,川滇块体存在显著的超阈值辐射增强异常。利用该地区通过震例总结得到的红外辐射异常特征,持续对川滇块体红外辐射进行了多年跟踪,在2022年9月5日四川泸定M_(S)6.8地震前,川滇块体又再次出现了类似的异常变化。泸定地震发生在川滇块体东边界的鲜水河断裂带磨西段。本研究主要分析泸定地震前红外辐射的异常变化。
文摘Research on the range anomaly suppression algorithm in laser radar (ladar) range images is significant in the application and development of ladar. But most of existing algorithms cannot protect the edge and linear target well while suppressing the range anomaly. Aiming at this problem, the differences among the edge, linear target, and range anomaly are analyzed and a novel algo- rithm based on neighborhood pixels detection is proposed. Firstly, the range differences between current pixel and its neighborhood pixels are calculated. Then, the number of neighborhood pixels is detected by the range difference threshold. Finally, whether the current pixel is a range anomaly is distinguished by the neighbor- hood pixel number threshold. Experimental results show that the new algorithm not only has a better range anomaly suppression performance and higher efficiency, but also protects the edge and linear target preferably compared with other algorithms.
基金sponsored by Special National Science and Technology Project on "Scientific research of fault zone of Wenchuan Earthquake"(the 15th Subject)the director fund of Institute of Geology of Chinese Academy of Geological Sciences
文摘Seismic tomography can provide both fine P-wave and S-wave velocity structures of the crust and upper mantle. In addition, with proper computation, Poisson's ratio images from the seismic velocities can be determined. However, it is unknown whether Poisson's ratio images have any advantages when compared with the P-wave and S-wave velocity images. For the purposes of this study, high- resolution seismic tomography under the eastern part of North China region was used to determine detailed 3-D crustal P- and S-wave seismic velocities structure, as well as Poisson's ratio images. Results of Poisson's ratio imaging show high Poisson's ratio (high-PR) anomalies located in the Hengshan-North Taihang-Zhangjiakou (H-NT-Z) region, demonstrating that Poisson's ratio imaging can provide new geophysical constraints for regional tectonic evolution. The H-NT-Z region shows a prominent and continuous high-PR anomaly in the upper crust. Based on Poisson's ratio images at different depths, we find that this high-PR anomaly is extending down to the middle crust with thickness up to about 26 kin. According to rock physical property measurements and other geological data, this crustal Poisson's ratio anomaly can be explained by Mesozoic partial melting of the upper mantle and basaltic magma underplating related to the lithospheric thinning of the North China craton.