共查询到20条相似文献，搜索用时 471 毫秒
1.
给出了在椭球面上利用GPS速度场计算地壳应变率张量的公式,利用华北地区GPS监测网1992年、1995年和1996年观测数据所得的速度场在椭球面上进行了应变率计算,得到了其最大剪切应变率、主应变率的图像;并利用1966年以来25次大于5.0级地震的地震矩张量,由Kostrov公式计算了地震应变率,对两种数据所得的应变率进行了比较分析;结合地质构造背景探讨了华北地区现今形变特征及地震危险性地区的分布. 相似文献
2.
华北地区地壳形变的GPS及地震矩张量反演分析 总被引：5，自引：0，他引：5
许才军 《武汉测绘科技大学学报》2000,25(6):471-475
给出了在椭球面上利用ＧＰＳ速度场计算地壳应变率张量的公式,利用华北地区ＧＰＳ监测网１９９２年、１９９５年和１９９６年观测数据所得的速度场在椭球面上进行了应变率计算,得到了其最大剪切变态为率、主应变率的图像;并利用１９６６年以来２５次大于５．０级地震的地震矩张量,由Ｋｏｓｔｒｏｖ公式计算了地震应变率,对两种数据所得的应变率地比较分析;结合地质构造背景探讨了华北地区现今形变特征及地震危险性地区的分布。 相似文献
3.
应用GPS速度场和地震数据反演中国大陆构造应变场 总被引：1，自引：0，他引：1
为获得更准确的中国大陆地壳应力应变场,文章基于ITRF2005全球地心坐标参考框架,采用高精度数据处理方法计算了中国地壳运动观测网络1999—2009年间的观测数据,获得了中国大陆GPS速度场以及相对欧亚板块的区域形变场,计算结果显示中国大陆形变运动仍是西强东弱的格局;并利用中国大陆同期近30年的地震矩张量及第四纪活动断层研究成果资料,联合反演了中国大陆区域的构造应变场,结果表明:从总体来看,应变相对集中的区域为喜马拉雅构造带、青藏高原、帕米尔高原、阿尔金断裂带、新疆天山及川滇地区,中国大陆区域过去10年的构造变化以挤压为主,拉张为辅。 相似文献
4.
川滇地区地壳应变场的GPS与地震矩张量联合反演研究 总被引：2，自引：1，他引：1
利用川滇地区1903～2003年间的84个地震矩张量和1998～2004年间214个GPs站速度观测值.采用方差分量估计方法确定联合反演中地震矩张量与GPS站速度值之间的权比例因子,计算分析了川滇地区的地壳应变场.结果表明:①采用方差分量估计确定联合反演中权比例因子的方法,得到的GPs站速度观测值的权比例因子为0.833,较地震矩张量的权比例因子0.167大,充分体现出分布相对合理的高精度GPS观测值在反演中的重要性;②川滇地区的应变场大致表现出如下的特征:主应变方向在30°N以北的区域为东西向;30°N以南、100°E以西的区域为北东向;30°N以南、100°E以东的区域为北西向. 相似文献
5.
GPS观测研究青藏东北缘的水平变形特征 总被引：1，自引：0，他引：1
推导了利用位移场计算主应变、面膨胀、最大剪应变的公式,通过2次重复GPS观测结果,计算了新青藏高原东北缘在1999～2001年间的水平主应变、面膨胀、最大剪应变等水平变形特征量的分布,并分析了在观测后发生的德令哈6．6级地震活动与变形场特征量之间的分布关系。采用力学理论对该地区的地质构造运动、局部形变特征与地震活动的关系进行了讨论。得出了一些有意义的结论和认识。 相似文献
6.
《测绘文摘》2008,(4)
CH20082017由GPS测量得到的喜马拉雅的现今构造变形=The Current Tectonic Deformation of Himalaya Range Obtained from GPS Measurement/张静华,李延兴,张俊青,张中伏(中国地震局第一监测中心)//测绘学报.- 2008,37(2).-135～141根据新的GPS观测结果建立西喜马拉雅(WH)、中喜马拉雅(CH)和东喜马拉雅(EH)块体的弹性运动模型。将块体运动分解为整体旋转与内部变形.WH向北运动,平均速率31.5mm/a;CHNNE向运动,平均速率31.1 mm/a;EHNE向运动,平均速率27.0mm/a。喜马拉雅山在总体上呈现S-N向缩短与NWW-SEE向伸展.山脉中部S-N向的缩短速率最大平均14.6mm/a,大约吸收了印度与欧亚板块汇聚速率的35.7%。山脉存在明显的NWW-SEE向伸展变形,西部与东北部之间E-W方向的伸展速率为11.0mm/a。山脉中段南边界的主压应变率 相似文献
7.
回顾了GPS观测技术在区域地壳形变监测应用中的相关理论和方法,探讨了其发展趋势,重点介绍了块体负位错运动模型及其反演和地表位移场拟合推估及应变分析方法,展望了时空分析方法在地壳形变信息提取中的应用前景。 相似文献
8.
根据新的GPS观测结果建立西喜马拉雅(WH)、中喜马拉雅(CH)和东喜马拉雅(EH)块体的弹性运动模型。将块体运动分解为整体旋转与内部变形。WH向北运动,平均速率31.5 mm/a;CH NNE向运动,平均速率31.1 mm/a;EH NE向运动,平均速率27.0 mm/a.喜马拉雅山在总体上呈现S-N向缩短与NWW-SEE向伸展。山脉中部S-N向的缩短速率最大平均14.6 mm/a,大约吸收了印度与欧亚板块汇聚速率的35.7%。山脉存在明显的NWW-SEE向伸展变形,西部与东北部之间E-W方向的伸展速率为11.0 mm/a.山脉中段南边界的主压应变率最大,都大于7.5×10-8/a,而主张应变率最小,都小于1.0×10-8/a.山脉的西南角与EH的西北部主张应变率最大,都大于3.7×10-8/a.印度板块对欧亚板块的强烈碰撞与持续推挤力,重力势能差和上地幔的拖曳力是喜马拉雅山现今构造变形的主要驱动力。 相似文献
9.
以1999-2004年间中国西部地区近650个GPS站点的观测资料为基础,采用二维“高张力样条”函数内插算法获得了连续地壳形变场。结果表明,相对于稳定欧亚参考框架,中国西部现今地壳运动西强东弱,北向运动从西向东逐渐减弱,东向运动逐渐增强,青藏高原东缘及附近地区是东向运动的消减区带;主应变从西向东由压缩应变转变为拉伸应变;最大剪应变主要位于喜马拉雅地块及其东部地区;中国西部地区地震活动在空间分布上似乎集中发生在印度板块北东向挤压欧亚板块的两条共扼带内,与地壳形变场有一定对应关系,地壳形变的高应变率区为中强地震多发地带。 相似文献
10.
华北地区活动地块边界带运动及块体内部变形分析 总被引：2，自引：0，他引：2
基于刚性块体和GPS稳定点组概念，用GPS稳定点组的水平速度值求出了各活动地块及华北亚板块的欧拉运动参数，推证了块体边界上的点相对运动速度矢量公式，通过该公式利用块体欧拉运动参数反演计算分析了地块边界带运动状况；通过块体欧拉运动参数反演计算各GPS观测点的背景运动速度，用观测点的实测运动速度减去各观测点的背景运动速度得出其实际变形值，进一步分析了各地块内部变形情况，并探讨了各活动地块的刚性特征。 相似文献
11.
We have determined approximate average rates of deformation in the Qinghai-Tibet plateau and its margins from the GPS data for last 10 years and the moment tensors from earthquakes between 1900 and 1999. We also determined the strain rate (seismic strain rate) associated with the seismic deformation using 254Mω≥5.0 earthquakes, and estimated the shortening and extension rates for every block in the area as well. We also estimated the strain rate (geodetic strain rate) by 80 GPS sites’ velocity vectors and analyzed characteristic of kinematics by two kinds of strain rates and discussed earthquake potential in the area. As a result, the deformation rates from seismic moment tensors and from GPS velocities are basically agreed with each other. It is feasible to analyze seismic risk by comparing geodetic strain rate with seismic strain rate based on the opinion that strain energy will be released through earthquake. It is concluded that there is no strong earthquake potential (>M7) in the Qinghai-Tibet plateau and its margins, but there is earthquake potential (>M5) in middle Tibet in a few years. 相似文献
12.
Research on the deformations in Qinghai-Tibet plateau and its margins by inverting seismic moment tensors and GPS velocities 总被引：1，自引：0，他引：1
We have determined approximate average rates of deformation in the Qinghai-Tibet plateau and its margins from the GPS data for last 10 years and the moment tensors from earthquakes between 1900 and 1999.We also determined the strain rate (seismic strain rate) associated with the seismic deformation using 254 Mw≥5.0 earthquakes,and estimated the shortening and extension rates for every block in the area as well.We also estimated the strain rate (geodetic strain rate)by 80 GPS sites' velocity vectors and analyzed characteristic of kinematics by two kinds of strain rates and discussed earthquake potential in the area.As a result,the deformation rates from seismic moment tensors and from GPS velocities are basically agreed with each other.It is feasible to analyze seismic risk by comparing geodetic strain rate with seismic strain rate based on the opinion that strain energy will be released through earthquake.It is concluded that there is no strong earthquake potential (＞M7) in the Qinghai-Tibet plateau and its margins,but there is earthquake potential (＞M5) in middle Tibet in a few years. 相似文献
13.
The existence of intra-plate deformation of the Sundaland platelet along its eastern edge in North Borneo, South-East Asia, makes it an interesting area that still is relatively understudied. In addition, the motion of the coastal area of North-West Borneo is directed toward a frontal fold-and-thrust belt and has been fueling a long debate on the possible geophysical sources behind it. At present this fold-and-thrust belt is not generating significant seismic activity and may also not be entirely active due to a decreasing shelfal extension from south to north. Two sets of Global Positioning System (GPS) data have been used in this study; the first covering a time period from 1999 until 2004 (ending just before the Giant Sumatra–Andaman earthquake) to determine the continuous Sundaland tectonic plate motion, and the second from 2009 until 2011 to investigate the current deformations of North Borneo. Both absolute and relative positioning methods were carried out to investigate horizontal and vertical displacements. Analysis of the GPS results indicates a clear trend of extension along coastal regions of Sarawak and Brunei in North Borneo. On the contrary strain rate tensors in Sabah reveal that only insignificant and inconsistent extension and compression occurs throughout North-West Borneo. Moreover, station velocities and rotation rate tensors on the northern part of North Borneo suggest a clockwise (micro-block) rotation. The first analysis of vertical displacements recorded by GPS in North-West Borneo points to low subsidence rates along the western coastal regions of Sabah and inconsistent trends between the Crocker and Trusmadi mountain ranges. These results have not been able to either confirm or reject the hypothesis that gravity sliding is the main driving force behind the local motions in North Borneo. The ongoing Sundaland–Philippine Sea plate convergence may also still play an active role in the present-day deformation (crustal shortening) in North Borneo and the possible clockwise rotation of the northern part of North Borneo as a micro-block. However, more observations need to be collected to determine if the northern part of North Borneo indeed is (slowly) moving independently. 相似文献
14.
15.
16.
Sridevi Jade Malay Mukul V. K. Gaur Kireet Kumar T. S. Shrungeshwar G. S. Satyal Rakesh Kumar Dumka Saigeetha Jagannathan M. B. Ananda P. Dileep Kumar Souvik Banerjee 《Journal of Geodesy》2014,88(6):539-557
We present new insights on the time-averaged surface velocities, convergence and extension rates along arc-normal transects in Kumaon, Garhwal and Kashmir–Himachal regions in the Indian Himalaya from 13 years of high-precision Global Positioning System (GPS) time series (1995–2008) derived from GPS data at 14 GPS permanent and 42 campaign stations between $29.5{-}35^{\circ }\hbox {N}$ and $76{-}81^{\circ }\hbox {E}$ . The GPS surface horizontal velocities vary significantly from the Higher to Lesser Himalaya and are of the order of 30 to 48 mm/year NE in ITRF 2005 reference frame, and 17 to 2 mm/year SW in an India fixed reference frame indicating that this region is accommodating less than 2 cm/year of the India–Eurasia plate motion ( ${\sim }4~\hbox {cm/year}$ ). The total arc-normal shortening varies between ${\sim }10{-}14~\hbox {mm/year}$ along the different transects of the northwest Himalayan wedge, between the Indo-Tsangpo suture to the north and the Indo-Gangetic foreland to the south indicating high strain accumulation in the Himalayan wedge. This convergence is being accommodated differentially along the arc-normal transects; ${\sim } 5{-}10~\hbox {mm/year}$ in Lesser Himalaya and 3–4 mm/year in Higher Himalaya south of South Tibetan Detachment. Most of the convergence in the Lesser Himalaya of Garhwal and Kumaon is being accommodated just south of the Main Central Thrust fault trace, indicating high strain accumulation in this region which is also consistent with the high seismic activity in this region. In addition, for the first time an arc-normal extension of ${\sim }6~\hbox {mm/year}$ has also been observed in the Tethyan Himalaya of Kumaon. Inverse modeling of GPS-derived surface deformation rates in Garhwal and Kumaon Himalaya using a single dislocation indicate that the Main Himalayan Thrust is locked from the surface to a depth of ${\sim }15{-}20~\hbox {km}$ over a width of 110 km with associated slip rate of ${\sim }16{-}18~\hbox {mm/year}$ . These results indicate that the arc-normal rates in the Northwest Himalaya have a complex deformation pattern involving both convergence and extension, and rigorous seismo-tectonic models in the Himalaya are necessary to account for this pattern. In addition, the results also gave an estimate of co-seismic and post-seismic motion associated with the 1999 Chamoli earthquake, which is modeled to derive the slip and geometry of the rupture plane. 相似文献
17.
大地测量联合反演理论和方法研究进展 总被引：1，自引：0，他引：1
许才军 《武汉大学学报(信息科学版)》2001,26(6):555-561
综述了10多年来国内外大地测量反演问题研究的成果及最新进展，特别是大地测量联合反演模型、大地测量联合反演算法以及大地测量联合反演理论和方法在研究地壳运动、地球构造等中的应用成果，讨论了联合卫星测高、声纳测深及海洋激光雷达遥感信息反演海洋环境参量，联合INSAR、GPS和水准资料反演研究地壳运动和联合各种观测数据反演研究地球内部构造问题。随着科学技术的发展，大地测量联合反演理论和方法研究将在监测全球变化、防灾减灾、发展地球科学理论方面取得更大进展。 相似文献
18.
基于1999年以来的GPS观测数据,重点分析了川滇地区近期的变形特征,计算给出了该区域主要断裂带的滑动速率,并结合GPS剖面初步识别了断裂带所处的孕震阶段。结果表明,红河断裂带始终处于弱形变区域,值得进一步关注;汶川地震后,由于研究区域应力场的调整和应变的重新分配,使得安宁河断裂带的活动变化较小,逐步趋缓,走滑分量存在明显趋缓现象,并且安宁河断裂带的闭锁深度在一定程度上有所增加;小江断裂带的走滑分量存在明显趋缓现象,显示存在强闭锁现象,小江断裂带平行于断层方向GPS速度剖面显示断裂带两侧变形平缓且变形范围较大;昭通、莲峰断裂的挤压和剪切变形积累均存在弱化现象,可能预示该区域挤压应变积累背景较高。 相似文献
19.
2015年4月25日尼泊尔地区发生了Mw 7.9级地震,发震断层位于印度板块与欧亚板块碰撞边界带,此次地震是一次典型的板块逆冲型事件。利用中国境内加密的GPS同震观测资料,融合ALOS-2卫星L波段的InSAR（interferometric synthetic aperture radar）同震形变数据,基于最小二乘方法获得了此次地震的同震垂直位移场。同震垂直位移结果表明,此次地震造成尼泊尔加德满都地区抬升约0.95 m,珠穆朗玛峰地区受地震的影响有所下降,其主峰的沉降量为2~3 cm,中国境内的希夏邦马主峰沉降约为20 cm。地区利用改进的二维弹性半空间位错模型反演了发震断层运动参数,本文模型显示此次地震的断层面破裂宽度约为60 km,平均滑动量达到4 m,相当于Mw 7.89级。 相似文献
20.
GPS地震仪:PANDA软件测试结果与验证 总被引：1，自引：1，他引：0
介绍了基于PANDA软件的高采样率GPS数据非差精密定位方法,为了验证高采样GPS技术与地震仪观测结果的一致性,进行了震动平台模拟数据试验。试验结果表明,高采样GPS和地震仪均能有效地恢复平台震动位移和震动主频率。对2010年Baja地震实际观测的GPS和强震仪进行分析,结果表明,利用高采样GPS技术不仅能成功获取地震波信号;而且能同时获得地表永久形变信息;而地震仪只能获取地震波信息,而不能直接获得地表永久形变信息。 相似文献