Average slip rate,earthquake rupturing segmentation and recurrence behavior on the Litang fault zone,western Sichuan Province,China

The Litang fault zone (LFZ) is an important active fault within the northwestern Sichuan sub-block. To-gether with the Garzê-Yushu, Xianshuihe, and An-ninghe fault zones on its northern, eastern and south-eastern sides, the LFZ constitutes the lateral extrusion tectonic system in the southeastern part of the Qing-hai-Tibetan Plateau[1,2] (Fig. 1). According to instru-mental records, historical recordings and field investi- gation, an earthquake (Ms7.3) occurred on its middle to south se…     

Co-seismic ground deformation and source parameters of Mani M7.9 earthquake inferred from spaceborne D-InSAR observation data

In recent ten years, Differential Interferometric Synthetic Aperture Radar (D-InSAR) has become a major technique of space-based geodesy together with GPS, VLBI and SLR. Interferometric Synthetic Aper-ture Radar (InSAR) has many advantages, such as all-weather, all-time, strong stability and dynamic survey property, and no requirements for ground sta-tions. In particular, the surveying results by InSAR can cover a large range of the ground deformation field in succession and has gr…     

岷山隆起边界断裂构造活动初步研究

岷山隆起西以岷江断裂为界,东为虎牙断裂。该地区构造活动强烈,地震活动频繁,是重要活动区。岷山隆起是岷江断裂和虎牙断裂由西向东的推覆逆掩运动差异运动导致的。GPS及地质研究表明岷江断裂、虎牙断裂现今仍在活动。岷江断裂为左右旋走滑断裂,运动速度大于2mm／a;虎牙断裂整体速度2．55mm／a,断裂性质为右旋走滑断裂,而震源机制解为左旋走滑断裂。这一结果,可能与GPS观测时段、位置及断裂面结构、几何特征有关。     

New geomorphic evidence for anticlinal growth driven by blind-thrust faulting along the northern Marche coastal belt (central Italy)

The Northern Marche coastal belt is characterised by a series of NW-SE trending, NE verging folds forming the easternmost edge of the Apennines thrust front. Several geomorphic features suggest that the folds are still growing and hence that the thrust front is active. The occurrence of several historical and instrumental earthquakes (e.g. 1672, 1690, 1786, 1875, 1916, 1930, 1972, all having M_e 5.2) suggests that the thrust faults are also seismogenic.We performed a geomorphological analysis to identify and characterise the faults driving the active folds. Our approach assumes that anomalous drainage patterns and deformed Middle-Late Pleistocene alluvial and coastal terraces are indicators of the vertical component of tectonic strain. We identified, mapped and correlated with sea-level fluctuations a sequence of alluvial and coastal terraces. Longitudinal profiles of six rivers (Conca, Foglia, Metauro, Cesano, Misa, and Esino) show that terraces (1) consistently converge downstream, suggesting that they result from regional uplift that dies out near the coast, and (2) some are slightly warped where they cross anticline axes. We interpreted as coastal terraces several land-surface remnants arranged parallel to the present coastline. Lower remnants clearly top off gently landward-tilted coastal deposits. Reconstructed coastal terraces also seem to be tectonically warped.Our results help characterise the geometry and segmentation of a system that generated the largest earthquakes of the region and suggest the loci of potential seismic gaps. We conclude that the earthquake potential of the densely populated northern Marche coastal belt may be substantially higher than currently estimated.     

基于模糊故障树的GIS产品的可靠性分析

本文首次把模糊故障树方法引入到GIS产品的可靠性分析,并就模糊故障树的基本理论作了简单的介绍,阐述了模糊故障树的建造和基于三角模糊数和梯形模糊数运算规则,结合GIS产品的特性论述了模糊故障树用于GIS产品可靠性分析的步骤,然后用实例进行了分析,最后就全文进行总结并指出了需要解决的问题。     

中国东部和西部地区水平向基岩加速度反应谱衰减关系

根据核安全法规和导则,对核电厂选址地震安全评价中发震构造与能动断层的关系,以及发震构造与能动断层鉴定的时代问题进行了分析,并结合近年来核电厂选址评价中存在的问题,对发震构造与能动断层的评价方法进行了探讨。     

海底热流长期观测系统研制进展

浅海和俯冲海沟等海域,不仅是矿产和油气资源主潜力区,也是构造地震频发区,其浅表热流和深部温度信息对于了解板块俯冲和岩浆活动等过程至关重要.这些区域浅层地温场和热流场受到底水温度波动(BTV)强烈扰动,其背景热流需由长期观测来获取.在全面分析了国内外海底热流长期观测技术特点后,我们提出了系缆式海底热流长期观测方案,201...     

利用断层自动剖分技术的2008年青海大柴旦Mw6．3级地震InSAR反演研究

2008-11-10青海大柴旦地区发生了Mw6．3级地震,其发震断层位于青藏高原东北缘的大柴旦一宗务隆山断裂带。利用欧空局Envisat／ASAR卫星雷达影像数据,采用二通差分干涉技术获得了地震的同震地表形变场,基于1D协方差函数估计InSAR同震形变场的中误差为0．52cm,方差一协方差衰减距离为5．9km。在此基础上,采用弹性半空间矩形位错模型进行断层几何参数反演,并利用断层自动剖分技术确定了地震的最佳同震滑动分布模型。结果表明,该地震的震源机制解为走向107．19°,倾角56．57°,以逆冲为主兼具少量右旋走滑分量;滑动分布主要发生在10-20km深度范围内,最大滑动量为0．51m,释放的能量为4．3×10^18Nm。