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本文分析了2010年10月-2011年3月云南通海ELF地震台站观测的电磁场资料,研究发现该资料变化与2011年发生在中国大陆"3·10"盈江5.8级及"3·24"缅甸7.2级地震存在以下关系,(1)470～1 Hz的磁场自功率密度谱(PSD)在2011年盈江5.8和缅甸7.2级地震前出现了脉冲丛集异常,异常幅度分别比正常月份变化约1～3个数量级.异常的幅度与观测点的电极方位和信号的频率有密切的关系.(2)2011年3月10日盈江地震的异常变化是先从地壳的深部向浅部发展,在震前25天2.6 km处的电阻率开始发生变化,震前10天400 m处的电阻率变化,出现了勺形的变化形态,阻抗相位同步变化.3月24日的缅甸7.2级地震,震前10天深部、浅部的电阻率同步发生了大幅度变化,阻抗相位发生转折,这可能是强震的变化特性. 相似文献
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Located in an earthquake-prone region,the geological structures in Yunnan Province are complex. Taking into account that Tonghai county is located in the intersection of Xiaojiang fault and Honghe fault, an ACF-4M ELF electromagnetic instrument was installed at the Tonghai seismic station,which has produced continuous reliable data. The author collected the data and information for the year 2009 and 2010,and performed analysis on the variation characteristics of both geomagnetic fields and electrical resistivity. The result shows that the 1Hz and 39Hz electromagnetic power spectra are 0. 2 to 1. 4 orders of magnitude higher than the normal values immediately before many earthquakes. The anomalies are represented by the abrupt changes of the electric and magnetic field power spectra in earthquake and aftershock sequences,and the amplitude of change is related to the size of earthquake magnitude and epicentral distance. The electrical resistivity also obviously changes. Therefore, further research on the anomalous characteristics of ELF electromagnetic data will be meaningful to the future use of this instrument in earthquake prediction. 相似文献
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中国地震电磁现象的岩石实验研究 总被引：8，自引：2，他引：6
介绍了近年来中国岩石电磁辐射实验的一些现象和结果。 相似文献
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舒曼谐振是由闪电激发的电离层与地面之间的全球电磁震荡,在地球与电离层空腔中传播,由于共振作用,其电磁波能量明显高于其他频率电磁波能量.舒曼谐振具有稳定的频域参数和频谱结构,近几年的研究发现,地震发生前会使这些固有参数发生扰动,因此利用舒曼谐振异常来进行地震短临监测可能是一种行之有效的手段.要判断舒曼谐振地震电磁异常,了解舒曼谐振电磁场背景变化规律是前提.本文利用极低频电磁台站观测的天然电磁场数据,处理和分析了各台站观测的舒曼谐振频率电磁场功率谱随时间的变化,得到了舒曼谐振随季节和纬度的背景变化规律.并提出将舒曼谐振背景变化规律应用到地震短临监测预报中,能够为今后辨别地震监测中的舒曼谐振异常提供物理依据. 相似文献
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利用JPL提供的TEC地图数据和日本NICT提供的测高仪数据分析了2011年3月11日日本MW9.0级特大地震(Tohoku-oki Earthquake)前上空的电离层变化.GIM TEC地图数据分析发现,3月1～4日GPS TEC在赤道异常区域出现了不同程度的负扰动,其中3月1日和2日的扰动幅度和范围较大,以上很可能是由于3月1日爆发的9小时磁暴所致;此外,震前3天即3月8日04-14UT期间赤道异常区电离层TEC出现了明显的增强现象,异常最大幅度达30TECU,并伴随有南半球磁共轭区增强现象.日本境内的4个电离层测高仪数据分析显示,3月8日4个台站同时出现了foF2增强现象,其中Okinawa和Yamagawa两个站增幅明显.分析发现震前3天地震上空区域电离层参量异常增强,认为这可能与大气层和电离层垂直电场的变化有关,这种电场的变化有可能是地震产生的电磁信号传播所致. 相似文献
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Through the analysis and 2-D inversion for the 5 profiles in Haiyuan arcuate tectonic region (105°～107°E,36°～37.5°N) in the northeastern margin of Qinghai-Xizang Plateau, we have obtained the electric structure within a range of 160 km in width (east-west) and 60 km in depth in the studied area. The results show that the crustal electric structure can be divided into 6 sections, corresponding respectively to Xiji basin (Ⅰ), Xihuashan-Nanhuashan uplift (Ⅱ), Xingrenbu-Haiyuan basin (Ⅲ), Zhongwei-Qingshuihe basin (Ⅳ), Zhongning-Hongsibu basin (Ⅴ) and west-margin zone of Ordos (Ⅵ) from the southwest to the northeast. The crustal electric structure is characterized by a broom-shaped pattern, which scatters to the northwest and shrinks to the southeast. The structures in the top part of Haiyuan arcuate tectonic region are complete and large, however, they diminish from the arc top to the northwest and southeast ends. In the depth from 0 km to 10 km, the resistivity is high in the sections Ⅱ and Ⅵ, but relatively low in the other four sections, showing a similar pattern of basin depression. The electrical basement in the section Ⅲ is the deepest, displaying a "dustpan" shape that is deep in the southwest and shallow in the northeast. A series of discontinuous zones with high conductivity exist in the middle-lower crust in Haiyuan arcuate tectonic region, which is possibly related to the moderate and strong earthquakes in the region. The resistivity distribution in the focal area of the 1920 Haiyuan earthquake is significantly heterogeneous with an obviously high conductivity zone near the hypocenter regime. 相似文献
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为了取得邢台地震区地壳细结构,对该区进行了综合地球物理方法探测,其中电磁阵列剖面法（EMAP）测量在我国尚属首次．EMAP剖面穿过邢台7．2级地震区,经过EMAP阻抗求取、空间滤波处理和二维反演解释,剖面显示出清晰的地壳电性细结构特征：4km以上电性简单,4—20km深度电性复杂;震源区电性复杂,非源区简单;发震深度变化复杂;震源区电性突变,显示隐伏高角度断裂,高寻层不连续部位为发震部位．其观测结果对于了解该区的构造背景、发震构造和深部构造的关系有重要意义． 相似文献
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黑龙江五大连池火山群地壳电性结构 总被引：11，自引：3，他引：11
对1997年在黑龙江五大莲池火山群观测的7条大地电磁测深剖面资料进行重新处理，对全部测点的实、虚感应矢量和视电阻率曲线等参数的分布特征进行了详细分析，应用NLCG二维反演方法对3条近东西向剖面数据进行了反演，获得的深部电性结构结果显示：五大莲池火山群中的笔架山-老黑山-火烧山火山链上的火山规模明显大于南、北格拉球火山链和东、西焦得布火山链，该带火山活动有从南西向北东推移的规律；以笔架山-老黑山-火烧山火山链为中心在地下约几百米深度到20km左右，存在一个北北东走向、上宽下窄、北宽南窄似铆钉的状体，该块体随着深度的增加其电阻率值从上千欧姆米逐渐减小到小于1欧姆米；在深度约20km以下铆钉的主体仍然显示有向深处延伸的趋势，推测一直穿过地壳与上地幔连接；在深度4～8km左右火烧山、老黑山和笔架山东、西两侧存在低阻块体；结合S波速度、小震活动以及地热研究结果分析，推测笔架山-老黑山-火烧山火山链在地壳内随着深度增大存在不同凝固程度的岩浆系统。 相似文献