韩城台倾斜异常特征及其与地震关系分析     

潘存英  白香玲  张彩霞  马雪侠 《高原地震》2008,20(3):42-45

通过对陕西韩城台倾斜资料的整理、分析与研究,指出了存在的干扰源;并在排除干扰的基础上采用21点斯宾塞平滑滤波方法探讨该台资料变化与周边地震活动的关系。  相似文献   

强地震引起的同震形变响应   总被引：18，自引：1，他引：17  

牛安福  张晶  吉平 《内陆地震》2005,19(1):1-7

以华北地区地倾斜、地应变数字化观测为基础,研究了形变同震响应的分布特征,给出了地震面波响应延迟时间、响应幅度、同震信号持续时间(在可分辨的范围内)等特征与地震震中距离及震级之间的关系,同时还探讨了短临形变前兆与未来地震之间可能存在的关系及地震短临预测面临的科学问题。  相似文献   

水平角观测时竖轴倾斜引起误差的改正方法探讨     

胡特彧  杨松林  田爱军 《北京测绘》2008,(2):43-46

对于水平角观测时垂直轴倾斜带来的影响,一是采用测回间重新整平的方法来削弱;二是在有竖盘指标水准管的情况下,读取格值施加改正数的方法来削弱。但这两种方法的精度有限,且对于无竖盘指标水准管的仪器目前没有提出相应的解决方法,＂虚拟目标法＂可以有效地解决这个问题。  相似文献   

东天山戈壁沙漠覆盖区重磁场特征与构造格架研究          下载免费PDF全文

曾凯  陈建国  肖凡 《江苏地质》2013,37(4):598-605

依据重力和航磁异常数据及其处理结果（Tilt导数和欧拉反褶积）,对东天山戈壁沙漠覆盖区断裂构造和岩体重新进行了解译,结合岩石密度和磁性特征及前人研究成果,分析了东天山的构造格架。结果表明,东天山构造线主体方向为近EW向,构造格局具有南北分带的特点,重力和航磁异常图上密集梯级带对应研究区一级断裂,即康古尔塔格一黄山深断裂和阿奇克库都克一沙泉子断裂。重力和航磁原始异常经过Tilt导数和欧拉反褶积处理后,微弱信息得到明显增强,进而识别出一些新的断裂构造和岩体。  相似文献   

海原形变观测资料异常分析     

张立强  柳忠旺  程鹏图  常兴 《高原地震》2010,22(2):45-51

对海原台CZB-1型竖直摆钻孔倾斜仪记录到的地表倾斜方向的异常变化进行了分析,同时对该台YRY-4型分量应变仪依据自检方法表现出的压缩及伸张性异常进行了提取,得出以上两测项观测资料在宁夏南部发生的3次Ms3．0级以上有感地震的2次地震前出现了一定的异常信息,与地震赢救蚺蕴。  相似文献   

大气变化对位移、重力和倾斜观测影响的理论计算   总被引：8，自引：1，他引：7       下载免费PDF全文

罗少聪  孙和平  徐建桥 《地球物理学报》2005,48(6):1288-1294

利用弹性地球负荷理论和流体静力学平衡假设条件下的干空气及其垂直温度梯度分布,理论计算了大气压力作用下地表位移、重力和倾斜格林函数．详细讨论了不同地球模型、台站高程、周边地形、地表大气温度和水汽含量等因素对计算结果的影响．数值结果说明大气效应弹性项影响主要来自于远离台站的区域;引力项对重力的影响主要贡献来自于台站近区,对倾斜的影响来自于远离台站的区域．各种因素对大气重力和倾斜格林函数的影响分别在01°和1°角距范围内,但其综合影响较为复杂．  相似文献   

Tilt梯度及其水平导数提取重磁源边界位置   总被引：7，自引：6，他引：1  

王想  李桐林 《地球物理学进展》2004,19(3):625-630

探讨了用于探测异常源边界和形状的Tilt梯度及其水平导数的方法及其性质．通过模型试算,论证了Tilt梯度及其水平导数的有效性,并从理论上给予了证明．Tilt梯度及其水平导数的方法及其性质可广泛用于区域重磁异常的构造解释之中。  相似文献   

Água Bonita pull apart basin and its relationship to Transbrasiliano Lineament     

《Journal of South American Earth Sciences》2019

The Transbrasiliano Lineament (TBL), a NE-SW trending strike slip system at least 2700 km long, is one of the main structures of the South American Platform. This lineament, along with other structures, influenced greatly the installation and depositional history of the Paraná and Parnaíba sedimentary basins. The Água Bonita Basin (ABB) occurs at an intermediate position between both basins. This work aims to provide information on the origin and evolution of the Água Bonita Basin, considered a Silurian-Devonian basin, as well as its relationship with the Transbrasiliano Lineament.Geological, aero and ground geophysics data were used to determine a structural geological model for the ABB located in the Brasilia Fold Belt in the Tocantins tectonic province. The airborne geophysical magnetic data used in the study were acquired in the 1970s by the existing 147 ground gravity stations in addition to the 498 new ground gravity and geodetic stations that were added to the existing ones.The analysis of the outcrops allowed identifying the sedimentary facies associations providing new information on the depositional environments. The compilation of existing data, satellite images analysis, geological maps and shaded relief provided an integrated model for the study area.A geological model was proposed for the ABB based on the interpretation, integration, depth analysis and 2D gravity forward modeling according to a theoretical model for an extensional duplex in a strike slip system with flower structures. We observed several segmented gravity anomalies, which were interpreted as steps/faults. This interpretation is consistent with a pull apart basin. According to the depth data estimated by this model, the maximum thickness of the Água Bonita Formation is 1.6 km and 2.4 km for the precursor rift. The basin has two dextral faults on each border, whose main fault of the TBL strike slip system and the master fault controlling the ABB are observed on the east border of the rift phase. Lineaments perpendicular to the west edge, in addition to those crossing the ABB in the N65E, delineate peculiar magnetic, gravity and geological signatures in the northern part of the basin. The basin is located in the weak region of the TBL and its main eastern fault is dipping sub-vertically to the west. This fault modeled up to the 8 km depth using the gravity data, was also observed in the Tilt Angle of the Total Horizontal Gradient (TAHG) matched filter grid result at approximately 8 km, however this may not be this fault maximum depth.Three main sedimentary-tectonic stages were observed, (i) a Pre-Devonian precursor rift present in the Água Bonita Basin and Jaibaras Group; (ii) the sag stage developed during the Devonian, when the Paleozoic basins of Paraná, Parnaíba and Água Bonita Basin were connected evidenced by the sedimentary facies and similar thicknesses; and (iii) the Pos-devonian rocks that are probably not preserved in the Água Bonita Basin.  相似文献   

Sonic Anemometer Tilt Correction Algorithms   总被引：72，自引：38，他引：72  

James M. Wilczak  Steven P. Oncley  Steven A. Stage 《Boundary-Layer Meteorology》2001,99(1):127-150

The sensitivity of sonic anemometer-derived stress estimates to the tilt of the anemometer is investigated. The largest stress errors are shown to occur for unstable stratification (z/L<0) and deep convective boundary layers. Three methods for determining the tilt angles relative to a mean streamline coordinate system and for computing the tilt-corrected stresses are then compared. The most commonly used method, involving a double rotation of the anemometers' axes, is shown to result in significant run-to-run stress errors due to the sampling uncertainty of the mean vertical velocity. An alternative method, requiring a triple rotation of the anemometer axes, is shown to result in even greater run-to-run stress errors due to the combined sampling errors of the mean vertical velocity and the cross-wind stress. For measurements over the sea where the cross-stream stress is important, the double rotation method is shown to overestimate the surface stress, due to the uncorrected lateral tilt component. A third method, using a planar fit technique, isshown to reduce the run-to-run stress errors due to sampling effects, and provides an unbiased estimate of the lateral stress.  相似文献   

倾斜扰动--一种可能的有效地震前兆   总被引：7，自引：0，他引：7  

许昭永  王贤仁  黄雍  杨润海  赵晋明  卢艳清 《地震研究》2001,24(2):131-135

依据小地震时的倾斜记录和岩石破裂时的应变扰动记录提出，岩石破裂和微小地震可能引起倾斜扰动，这种扰动将可能是大地震的有效前兆。然而，如何区分干扰和前兆扰动还需仔细研究。  相似文献