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1.
威特DI2002测距仪实测精度分析   总被引:1,自引:0,他引:1  
祝意青  巩地文 《地震研究》1997,20(3):332-338
通过对威特DI2002测距仪的实测资料的分析,认为(1)DI2002测距仪实测精度较高,与ME-3000测距仪具有同等的实测精度,(2)DI2002仪器性能稳定,加、乘常数变化幅度小,频率变化也很小,其频率的稳定性远比ME-3000测距仪匹配的测频仪高。(3)DI2002与ME-3000测距成果有很好的一致性。在ME-3000测距仪老化的情况下,可以用DI2002替代ME-3000用于跨断层水平形  相似文献   

2.
青藏高原北部地区前兆台网分布及前兆监测能力   总被引:1,自引:0,他引:1  
收集了青藏高原北部地区流体、形变、电磁三大学科90个定点前兆观测台项和69个跨断层流动测量场地的基础资料,提出前兆反映能力的概念和计算其空间分布的方法,对该区前兆观测台网的分布、前兆反映能力和监测能力进行了分析。  相似文献   

3.
依据福建地区最新的跨断层资料,结合福建地区地震地质构造及历年来对福建地区跨断层场地的研究分析成果,对福建地区天马定点形变场地、17个流动跨断层场地及所有跨断层场地形变速率强度进行分析.研究表明,龙岩-厦门-东山区域、闽粤交界区域形变速率较大,值得进一步研究.  相似文献   

4.
本文介绍了辽宁地区跨断层场地水准测量情况,利用测量成果所揭示的垂直形变信息,探讨r跨断层场地水准测量在地震监测预测中发挥的作用。  相似文献   

5.
断层活动应力轴的确定及首都圈应力场   总被引:2,自引:0,他引:2  
本文从应力应变关系的基础上给出了利用断层形变资料计算断层活动的水平主应力方向的公式,并用邢台、唐山和海城的地震断层形变资料求解了主应力方向,其结果和震源机制解一致。还用首都圈跨断层资料计算了水平主应力轴,结果表明主应力优势方向为NE50°~NE70°,近10年来总趋势无显著变化  相似文献   

6.
介绍了青藏高原北缘跨断层垂直形变监测情况及提高监测质量的工作经验,该地区的监测成果较好地反映了测区内几次地震孕育、发生过程中断层形变的中短期异常变化信息。  相似文献   

7.
通过跨断层形变测量,可以计算求得断层位移量。有多余观测数据时、可以采用测量相差法求得跨断层点位之间的相对位移量。但有时这样求出的各点位移量大小不一,甚至互相矛盾。本文试图提出一种方法,即利用跨断层测量成果,结合测量场地附近一定范围内的地  相似文献   

8.
对克孜尔水库跨断层垂直形变近40年的资料和水平形变近32年的资料进行了分析。研究发现,①跨断层形变的变化速率具有明显的不均匀性,根据数据序列走势,变化速率的不同可分为6个阶段;②水库施工对跨断层形变有一定的影响,水库蓄水对跨断层形变有显著的影响;③水库蓄水达到正常库容量后的新平衡状态下,跨断层形变速率变化几乎是无干扰背景下变化速率的2倍;④区域应力场的增强对跨断层形变趋势性转折有显著性影响。  相似文献   

9.
利用呼图壁地震台洞体场地水准二期的比对观测数据、呼图壁场地跨断层水准四期的同时间段观测资料以及1987~2012年大丰跨断层测线的水准观测数据,分析了呼图壁红山地震台洞体场地水准观测成果的变化速率与跨断层水准观测成果的年变速率的差异性,判定原地震台使用的Ni004光学水准仪的可靠性,依据分析结果提出合理建议。并根据大丰跨断层水准观测的历史观测成果和呼图壁洞体场地水准观测比对后的分析结果,初步探索研究跨断层水准在研究区域的地形变特征。  相似文献   

10.
利用呼图壁地震台洞体场地水准二期的比对观测数据、呼图壁场地跨断层水准四期的同时间段观测资料以及1987~2012年大丰跨断层测线的水准观测数据,分析了呼图壁红山地震台洞体场地水准观测成果的变化速率与跨断层水准观测成果的年变速率的差异性,判定原地震台使用的Ni004光学水准仪的可靠性,依据分析结果提出合理建议。并根据大丰跨断层水准观测的历史观测成果和呼图壁洞体场地水准观测比对后的分析结果,初步探索研究跨断层水准在研究区域的地形变特征。  相似文献   

11.
In this paper we study the application of different geodetic techniques to volcanic activity monitoring, using theoretical analysis. This methodology is very useful for obtaining an idea of the most appropriate (and efficient) monitoring method, mainly when there are no records of geodetic changes previous to volcanic activity. The analysis takes into account the crustal structure of the area, its geology, and its known volcanic activity to estimate the deformation and gravity changes that might precede eruptions. The deformation model used includes the existing gravity field and vertical changes in the crustal properties. Both factors can have a considerable effect on computed deformation and gravity changes. Topography should be considered when there is a steep slope (greater than 10°). The case study of Teide stratovolcano (Tenerife, Canary Islands), for which no deformation or gravity changes are available, is used as a test. To avoid considering topography, we worked at the lowest level of Las Cañadas and examined a smaller area than the whole caldera or island. Therefore, the results are only a first approach to the most adequate geodetic monitoring system. The methodology can also be applied to active areas where volcanic risk is not associated with a stratovolcano but instead with monogenetic scattered centers, especially when sites must be chosen in terms of detection efficiency or existing facilities. The Canary Islands provide a good example of this type of active volcanic areas, and we apply our model to the island of Lanzarote to evaluate the efficiency of the monitoring system installed at the existing geodynamic station. On this island topography is not important. The results of our study show clearly that the most appropriate geodetic volcano monitoring system is not the same for all different volcanic zones and types, and the particular properties of each volcano/zone must be taken into account when designing each system.  相似文献   

12.
We evaluated fault activity in northeast–central Japan based on fault orientation, regional stress field, and slip tendency analysis for active and non‐active faults (i.e. faults for which Quaternary activity has not been identified). Slip tendency is generally higher along active faults than non‐active faults, although a high slip tendency was observed along some non‐active faults, indicating their potential to become active. The potential for fault activity along non‐active faults can be modeled using the temporal evolution from non‐active to active during long‐term crustal deformation. The density of potentially active faults varies spatially across the study areas and reflects the temporal evolution of crustal deformation in northeast–central Japan.  相似文献   

13.
GPS应变率场计算方法研究进展   总被引:1,自引:0,他引:1  
王静 《地震》2019,39(2):122-134
基于大地测量资料获取地壳运动与应变积累定量结果一直是国内外重视的地震中长期预测的技术途径。 针对地震变形过程的准确描述问题, 国内外学者基于GPS资料, 发展了多种应变率场解算方法。 本文首先简要介绍了GPS应变率计算的基本原理, 然后系统梳理了国内外多种计算方法的优势和不足, 结果表明: 应变率计算的数学方法只考虑几何关系, 其中整体方法主要适合数据密度和分布较好条件下获取区域地壳变形分布与趋势, 局部方法主要适用于数据较为稀疏情况下描述构造块体的变形特征; 应变率计算的物理方法既考虑几何关系又考虑物理关系, 其中, 位错方法根据主要适合于研究区域存在主控断层的情况(研究区域的变形主要由少数断层控制); 数值模拟方法(如有限元法)主要适用于区域地质、 地球物理的资料比较完备的情况。  相似文献   

14.
用全球定位系统(GPS)监测青藏高原地壳形变   总被引:7,自引:5,他引:7       下载免费PDF全文
王琪  游新兆 《地震地质》1996,18(2):97-103
通过对拉萨、日喀则地区两条基线的观测结果分析,得到了拉萨地块近南北向地壳形变率为(7.0±2.3)mm/a及近东西向(7.4±2.3)mm/a的形变速率,与震源机制解的结论十分接近。同时监测到相对于拉萨南北向7.3cm和东西向4.1cm的震后形变位移,显示出GPS在地震监测及与地震相关的地壳形变研究的广阔前景  相似文献   

15.
Mountain ranges that are actively forming around the western and northern perimeter of the Indo-Eurasia collisional deformational field, such as the Mongolian Altai, comprise a unique class of intracontinental intraplate transpressional orogen with structural and basinal elements that are distinct from contractional and extensional orogens. Late Cenozoic uplift and mountain building in the Mongolian Altai is dominated by regional-scale dextral strike-slip faults that link with thrust and oblique-slip faults within a 300-km-wide deforming belt sandwiched between the more rigid Junggar Basin block and Hangay Precambrian craton. Dominant orogenic elements in the Mongolian Altai include double restraining bends, terminal restraining bends, partial restraining bends, single thrust ridges, thrust ridges linked by strike-slip faults, and triangular block uplifts in areas of conjugate strike-slip faults. The overall pattern is similar to a regional strike-slip duplex array; however, the significant amount of contractional and oblique-slip displacement within the range and large number of historical oblique-slip seismic events renders the term “transpressional duplex” more accurate. Intramontane and range flanking basins can be classified as ramp basins, half-ramp basins, open-sided thrust basins, pull-apart basins, and strike-slip basins. Neither a classic fold-and-thrust orogenic wedge geometry nor a bounding foredeep exists. The manner in which upper crustal transpressional deformation is balanced in the lower crust is unknown; however, crustal thickening by lower crustal inflation and northward outflow of lower crustal material are consistent with existing geological and geodetic data and could account for late Cenozoic regional epeirogenic uplift in the Russian Altai and Sayan regions.  相似文献   

16.
GPS技术监测地壳运动的新进展   总被引:1,自引:1,他引:0       下载免费PDF全文
陈光保 《地震工程学报》2009,31(3):302-307,310
回顾了GPS观测技术应用于地壳运动与形变中的相关理论与方法,重点介绍了水平应变的计算方法与描述地壳运动与形变场的各种数学物理方法,讨论了提取地壳运动与形变信息过程中存在的问题.  相似文献   

17.
归纳了自1975年以后华北地区13次中强以上地震的地壳形变短临前兆异常60例。统计地壳形变短临异常与地震的定性关系,发现距震中较远的台站异常出现较早,较近的台站异常出现较晚,地震的震级与异常的空间展布范围成正比,异常往往倾向震中或背向震中。跨断层的位移型形变异常形态有两大类:一类是趋势性异常变化,另一类是高频波动。本文提出了将连续型形变转化为应变的方法。从1989年10月16日大同-阳高61级地 震和1991年3月26日大同-阳高5.8缓地震的实例可见,地震往往发生在高应变区或其附 近,异常量级可达10-6。  相似文献   

18.
本文以中国西部大地形变监测与地震预测实践为基础, 简要总结回顾了利用大地形变进行强震预测研究的工作思路、方法和一些进展; 进而结合2001年昆仑山口西8.1级、 2008年四川汶川8.0级特大地震前区域地壳运动变形背景和已有的研究结果, 分析和探讨了基于大地形变监测、 并考虑地震构造的差异性来进一步提高大震预测的有效性...  相似文献   

19.
In this paper,the corresponding relation of the evolutionary characteristics of geodetic deformation fields with seismic activity for more than 20 years in the North-South seismic zone and East of Qinghai-Xizang Mess has been investigated.Not only is geodetic deformation in non-homogeneity for the space-time distribution but also deformation fields are in macroscopic similarity for the identical time interval.The inherited tectonic movement is a total tendency of recent crustal movement,and the motion mode is in undulations.There are stages of accumulation and release-adjusting of strain energy in crustal movement processes,which may be the dynamic mechanism of relatively quiet and active seismicity.The analysis of the crustal movement tendency since 1991 is of some significance for judging the stress state and the large seismic situation in the area.  相似文献   

20.
南北地震带和青藏块体东部近期大地形变与地震特征   总被引:8,自引:1,他引:8  
江在森  王双绪 《中国地震》1997,13(2):139-150
通过研究南北地震带及青藏块体东部地区20多年来大地形变场演化特征及其与地震活动的呼应关系,发现大地形变既具有时空分布的不均匀性,各分区形变场又具有同时段的宏观相似性;继承性运动是现代地壳运动的总趋势,而运动方式为波浪式,涌动式推进。地壳运动过程中存在着区域为能积累阶段和释放调整阶段,这可能是地震活动的相对平静与活跃的动力机制。  相似文献   

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