2004～2007年晋、冀、蒙交界区重力场变化特征     

胡博  戴勇  邹家义 《高原地震》2008,20(4):8-13

系统分析了晋、冀、蒙交界区2004—2007年间的流动重力测量资料,研究了重力场的时空动态演化特征。结果表明：地震孕育发生阶段,重力场出现一定范围的区域性重力异常,重力场变化与区域应力应变场变化及地震活动有关。目前,在晋、蒙交界的怀仁-山阴-朔州-带存在趋势性的重力负异常。  相似文献   

区域重力工作在煤田勘查中应用效果     

陶鹏飞  李延清  姚卫星 《新疆地质》2019,(2):172-176

据三塘湖勘查区区域重力勘查工作,推断断裂体系、局部构造和预测煤田,取得找煤突出效果,反映重力勘查具快速高效和有效性特点,对同类或相似地区煤田勘探工作具借鉴作用。  相似文献   

Decimation and Spectrum Correlation Analysis of Gravity Solid Tide Signal Based on Surface-Simplex Swarm Evolution Optimization Algorithm     

Xinbao Yi  Wei Wei  Haiyan Quan 《地球科学进展》2019,34(2):148-155

In order to reveal the correlation between the harmonic components in the earth's solid tidal wave and the non-correlation superposition relationship, and based on these relations, the tidal harmonic implicit in the gravitational solid tidal signal was analyzed. According to the position relationship among the Earth, the moon and the sun's rotating orbit, an orthogonal decomposition model of tidal force was established. Furthermore, on the orthogonal decomposition model of gravity solid tidal wave based on the independent component analysis of the improved SSSE intelligent optimization algorithm, the spectral correlation method was used to analyze the independent components of gravity solid tidal wave. Thus, the multiplicative demodulation after the orthogonal decomposition of the conformal wave was completely realized. Finally, the above model and algorithm were used to compare and analyze the actual observation data and the theoretical signal as reference background. The results show that the proposed model and method can effectively achieve the orthogonal decomposition of tidal harmonics, highlight the weak energy of the long period harmonics component, and reflect the change of tidal harmonic modulation relationship from the spectral correlation map.  相似文献   

利用重力地形导纳估计月壳厚度   总被引：9，自引：4，他引：5       下载免费PDF全文

李斐  柯宝贵  王文睿  鄢建国 《地球物理学报》2009,52(8):2001-2007

在频域使用多窗口(Multitaper)方法来计算月球正面四个形成于不同历史时期月海区(Smythii, Crisium, Imbrium, Orientale)的重力地形导纳,然后将其与月球弹性岩石圈的理论导纳模型相比较,由最小二乘法得出四个月海区的月球岩石圈的平均弹性厚度约为8 km,月壳的厚度分别为：Smythii 盆地,72 km; Crisium 盆地 70 km;Orientale 盆地 60 km;Imbrium 盆地57 km.随着月球的演化,月壳厚度呈现变厚的趋势.  相似文献   

龙门山断裂带重力变化与汶川8.0级地震关系研究   总被引：7，自引：2，他引：5       下载免费PDF全文

祝意青  徐云马  吕弋培  李铁明 《地球物理学报》2009,52(10):2538-2546

利用成都地区1996~2008年绝对重力和相对重力观测资料获得区域重力场时空动态变化结果,系统分析了龙门山断裂带重力场变化特征及其与汶川8.0级地震的关系.①重力变化与龙门山断裂构造活动存在密切空间联系,重力测量较好地反映了伴随活动断层的物质迁移和构造变形引起的地表重力变化效应.②成都地区重力场动态图像较完整地反映了2008年5月12日汶川8.0级地震孕育、发生过程中出现的流动重力前兆信息.③映秀及北川重力点值时序变化累积量达120×10^-8m·s^-2,较好地反映了汶川地震前映秀和北川两个极震区附近的重力测点随时间的剧烈波动性上升变化.④汶川地震前,龙门山断裂带东侧的四川盆地相对稳定,而较显著的重力变化发生在龙门山断裂带西侧的川西高原上.  相似文献   

从深部断裂系统讨论肇庆地区的发震构造     

任镇寰  黄剑涛  何晓灵  孙崇赤  刘天佑  乔计花  魏伟  刘大为 《华南地震》2009,29(1):42-52

对肇庆地区重磁资料系统处理得到的图像进行解释和研究,认为肇庆地区深部存在近东西向、北西向、北东向三组断裂系统,东西向肇庆-广州断裂横贯全区,深及30km以上。北西向肇庆-开平断裂图像反映很清楚,但切割深度相对较浅,在10km左右。北东向吴川-四会断裂规模较大,切割深度在20km左右。其中近东西向是深部主要断裂系统,也是主要活动断裂,它与北西向断裂交汇部位是中强震主要发震构造。  相似文献   

Sill dynamics and fjord deep water renewal: Idealized modeling study     

Dmitri Leonov  Mitsuhiro Kawase 《Continental Shelf Research》2009

Fjord exchange circulation and its response to abrupt changes in forcing is examined by means of an idealized modeling experiment. Puget Sound, a fjord-type estuary in western North America (State of Washington), is the main context for this study. Parameters of the idealized model are representative of the entrance sill at Admiralty Inlet and the Main Basin of Puget Sound. Sensitivity to some of the model parameters relevant to a 3D realistic model is discussed. An idealized tidal forcing with fortnightly modulation drives a qualitatively realistic cycle of exchange circulation while the other boundary conditions are kept fixed in time. The cycle is characterized by fortnightly pulses of deep water intrusions with a sharp front at the leading edge and reversed circulation cells below the sill depth developing between the intrusions. This basic state is then perturbed and response of the circulation to abrupt changes in oceanic salinity and river discharge is examined.  相似文献   

Gravity anomaly, lithospheric structure and seismicity of Western Himalayan Syntaxis     

V. M. Tiwari  R. P. Rajasekhar  D. C. Mishra 《Journal of Seismology》2009,13(3):363-370

A compiled gravity anomaly map of the Western Himalayan Syntaxis is analysed to understand the tectonics of the region around the epicentre of Kashmir earthquake of October 8, 2005 (Mw = 7.6). Isostatic gravity anomalies and effective elastic thickness (EET) of lithosphere are assessed from coherence analysis between Bouguer anomaly and topography. The isostatic residual gravity high and gravity low correspond to the two main seismic zones in this region, viz. Indus–Kohistan Seismic Zone (IKSZ) and Hindu Kush Seismic Zones (HKSZ), respectively, suggesting a connection between siesmicity and gravity anomalies. The gravity high originates from the high-density thrusted rocks along the syntaxial bend of the Main Boundary Thrust and coincides with the region of the crustal thrust earthquakes, including the Kashmir earthquake of 2005. The gravity low of HKSZ coincides with the region of intermediate–deep-focus earthquakes, where crustal rocks are underthrusting with a higher speed to create low density cold mantle. Comparable EET (∼55 km) to the focal depth of crustal earthquakes suggests that whole crust is seismogenic and brittle. An integrated lithospheric model along a profile provides the crustal structure of the boundary zones with crustal thickness of about 60 km under the Karakoram–Pamir regions and suggests continental subduction from either sides (Indian and Eurasian) leading to a complex compressional environment for large earthquakes.  相似文献   

胶东测区重力场时空动态演化特征     

陆汉鹏  佟瑞清  韩海华  吕子强  曲建亭  李建奎  赵会蓬  付希庆 《高原地震》2010,22(2):32-38

系统分析了胶东测区1996—2009年期间流动重力测量资料,着重探讨了1996年以来相邻期的重力点值的空间变化规律,重力场有规律的变化表现为：胶东测区自观测以来有着活跃-平静-活跃-逐渐稳定的变化过程。另外,分析了胶东测区内断裂带附近的部分测点的点值和段差值变化特征,认为重力场变化与活动断裂构造密切相关,从而进一步加深了对胶东测区重力场时、空、强动态演化特征的初步认识,这为今后对山东地区重力场深入分析和研究打下了坚实的基础。  相似文献   

古田地震水口水电站重力坝强震观测记录的谱结构特征     

郑师春  张锦福  赵志伟  连玉平 《华南地震》2010,30(1):68-75

通过对水口水电站重力坝强震反应台站在古田地震中获取的强震反应观测资料进行信噪比、反应谱和功率谱分析,得到如下结论:①大坝在0.7～15 Hz频率段的振动特性较为可信;②坝基和自由场输入地震动富于高频,峰值加速度反应谱存在较大差异;③坝基输入地震动存在差异性,建议今后此类大坝抗震设计时考虑多点地震动输入;④单个卓越频率携带的能量对反应谱影响不大,反应谱是和输入地震动总能量相关的;⑤坝体刚度较大,此次地震中还处于线弹性状态。初步了解了强震记录的地震动特性和大坝结构的抗震性能,对认识水库地震近场地震动特性和重力坝地震反应有一定的参考意义。  相似文献