卫星热红外遥感在地震预测和断层活动中的应用研究进展

近年来,利用卫星技术通过测量地—气系统的红外辐射来探测地表的热状况,使热红外遥感在地震预测方面取得了显著成就。本文回顾了红外遥感资料应用于地震预测的研究成果,阐述了地震热红外短临预测方法的研究进展及应用实效,介绍了利用热红外遥感信息研究断层活动变化的探索与发展,探讨了地震热红外异常发生的机理,并就该技术的应用与理想效果之间的差距提出了未来工作的研究重点。     

隐伏断层在强震砂土液化中的作用——以2008年汶川Mw 7.9地震为例

2008年汶川Mw7.9地震的强地面震动在龙门山前地区造成大量的砂土液化、喷砂冒水等地震灾害现象。震后野外调查发现,砂土液化点主要分布于地下水位只有几米深的山前河流的低阶地处,以大面积砾性土液化为特征,约58%的液化点位于距北川断层20~35km的范围内。对喷水高度及喷水过程进行了详细记录,喷水高度与峰值加速度并没有明显的相关性,喷水高度异常点(2m)集中于山前断裂系统近地表投影处。汶川地震中喷水高度异常、砾性土液化的位置与山前断裂系统的吻合性说明,沉积盆地内的地质构造可能在砂土液化强度和与震动相关的地震灾害方面起到促进作用,所以在类似的地质和水文环境中,除主震的断层错动外,应考虑地质构造在地震危险性评估和建筑物抗震设计中的重要作用。     

基于统计学的随机地震反演在储层预测中的应用——以蜀南某地区嘉陵江组储层预测为例

在钻井资料较少的勘探开发初期,现今流行的地震反演方法难以准确预测储层.如递推反演分辨率不高;基于模型反演和随机模拟地震反演技术依赖大量井资料,在井资料较少的情况下,反演结果可靠性不高等.基于统计学的概率密度函数,随机地震反演引用测井资料参与反演约束,能有效地提高反演结果分辨率,并能充分考虑地下地质的随机特性,使反演结果更符合实际地质情况.同时,通过对测井资料概率密度函数的求取来实现反演,解决了随机模拟地震反演的变差函数在井资料较少,甚至在工区内井分布不均匀的情况下,变得极不稳定而使反演结果可靠性不高的问题,能较为准确地预测出储层低速异常带的分布.该方法在蜀南嘉陵江组储层预测中的成功应用表明,在薄储层且勘探初期钻井资料较少,且现今流行的叠后反演方法不能准确预测储层的情况下该方法能取得很好的应用效果.     

地震相控非线性随机反演在海上薄互层储层预测中的应用——以K油田沙河街组为例

针对渤海中深层薄互层储层普遍存在的埋藏深、地震资料品质差、储层厚度薄,薄互层沉积,储层横向变化快等特点,以及开发程度的加深对地震分辨率精度要求越来越高的情况,在分析储层组合和地震沉积学基础上,提出地震相控非线性反演方法,以期提高储层预测精度。该方法通过非线性最优化理论综合约束反演与模型反演的优点,根据实际地震资料建立反演目标层段的宏观相控模型,在测井资料约束下采用非线性随机算法逐道、逐次进行外推反演,有效提高地震资料的分辨率,充分考虑地质条件的随机特性,使反演结果更符合实际地质情况。在K油田应用表明,该技术提高了薄互层储层预测精度,为类似油田的储层预测、注采连通、井网部署提供可靠依据。     

综合勘察方法在活动断层填图中的应用——以锦屏山-小金河断裂(四川境段)为例

锦屏山-小金河断裂(四川境段)部分区域地面断层出露较差、地貌特征不明显,根据现场实际情况,采用资料收集分析、浅层地震勘探、高密度电法勘探和探槽开挖相结合的综合勘察方法,多种方法相互验证、进行综合解释分析,重点查明活动断层位置、几何特征形态、错断地层时代等,为1:5万活动断层填图工作提供重要依据。     

地震分频技术在扇三角洲前缘砂体预测中的应用 ——以海拉尔盆地乌尔逊断陷铜钵庙断裂带南屯组为例

海拉尔盆地乌尔逊断陷构造复杂、断裂发育,发育扇三角洲前缘含油砂体.针对含油砂体分布范围小、厚度薄、预测难的问题,通过地震匹配追踪分频处理,得到频率域的离散调谐地震数据体,其地震剖面波形特征清晰、能量增强、分辨率提高.应用优势频率分频三维地震资料,精细刻画了铜钵庙断裂带南屯组扇三角洲前缘砂体的三维轮廓和有利储层分布,并通...     

三维地震资料在古应力场反演和裂缝预测中的应用——以胜利油田富台潜山为例

针对古构造应力场反演计算中建立“古构造模型”和“约束条件”时所存在的问题,本文提出了应用三维地震资料进行古构造应力场反演的思路和方法,并以富台潜山为例,阐述了如何用三维地震资料来解决古构造应力场研究的“定时”、“定向”和“定量”问题。胜利油田富台潜山研究的实践表明:三维地震资料可以用来较好地解决古构造应力场研究中的“三定”问题,其结果的可靠性总体可以得到保障。因此,据于三维地震资料精细解释而进行的古应力场数值反演是古应力场研究的有效途径,同时也为裂缝的预测提供了基础。     

虚拟井约束地震反演方法在台地斜坡带鲕滩储层预测中的应用——以四川盆地龙岗地区某单元为例

目前的地震反演均是基于已钻井的地质信息,对无井或少井地区的地震储层预测仍然比较困难。采用叠前和叠后混合反演的办法,实现虚拟井约束地震反演,能弥补缺少钻井的缺陷。该方法充分利用了叠前反演分辨率高和叠后反演效率高、抗噪能力强的优点,运用遗传算法原理,在优选控制点处进行精细的叠前地震波形反演以构建虚拟井,然后以虚拟井作为约束信息进行叠后反演,能够达到储层预测的目的。对四川盆地龙岗地区无井台缘斜坡带鲕滩储层进行了应用尝试,预测效果较好。虚拟井约束地震反演方法对油气勘探初期少井或无井研究区的储层预测是行之有效的技术方法之一。     

“演绎-迭代”勘查方法在大比例尺成矿预测中的应用——以河南石寨沟金矿找矿为例

"演绎-迭代"勘查方法包括"归纳-演绎-反演-验证-迭代"五个步骤,是成矿预测理论与大比例尺内成矿预测实践相结合的有效接口。"归纳"是对比研究已知典型矿床的特点,分析区域控矿构造,总结区域成矿规律;"演绎"是结合矿区内自身成矿控矿特点建立矿床勘查模型;"反演"是应用地质、地球物理、地球化学手段对成矿空间进行定位和对成矿特征认识的再深化;"验证"是将勘查工作向实物成果的转化;"迭代"是建立勘查工作的循环,随着循环的不断推进,会越来越逼近真实的矿床形成演化机制,不断扩大控制矿体赋存空间。以河南石寨沟金矿为例,在"成矿系列"和"变质核杂岩"区域构造控矿模型指导下,应用"迭代-演绎"勘查方法,综合应用伽玛能谱、高精度磁法、高密度电法等勘查手段,结合地质资料进行综合解译,预测有利找矿区域,并得到了钻探工程的有效验证。     

断裂两盘井水位同震响应特征对比分析——以北京八宝山断裂带中段大灰厂两观测井为例

地震常引起分布于断层两盘观测井的水位同震响应动态变化特征不同。而研究断裂两盘观测井同震响应能力、水位变化特征的差异性及其控制因素,有助于揭示断裂带的渗透性演化过程、可深化地下水位对地震响应机理的认识,对于指导地震观测井网布局具有重要意义。本文尝试从北京八宝山断裂带中段（大灰厂）上下两盘井的水位同震响应次数、形态、幅度、记震能力等方面进行对比分析,通过去除趋势项,采用数字滤波求取井孔气压系数,采用Baytap-G程序求取潮汐参数,并反演出7次大地震对大灰厂区两口井所在含水层产生的体应变量,进而判别两盘震前震后渗透性的变化。结果显示,两口井同震响应特征具有明显差异,上盘井对大震的同震响应次数较多、能力较强;这不仅与断裂带起屏蔽作用有关,而且与井所处含水层渗透性呈不同规律变化密切相关。     

In-situ Stress Measurements in the WFSD-1?Borehole?at the Wenchuan Earthquake Fault

<正>supported by the Science and Technology Project of China(grant no.WFSD-00003),focuses on the in-situ stress measurements in the WFSD-1 borehole Stress is defined as the natural stress existing between     

Progress in the Application of Ground Gravity Observation Data in Earthquake Prediction

The mechanism of earthquake inoculation and the process of earthquake occurrence are very complicated. Additionally, earthquakes do not happen very often, and we lack enough cognition to the earth’s interior structure, activity regularity and other key elements. As a result, research progress about the theory of earthquake precursors has been greatly restricted. Ground gravity observation has become one of the main ways to study earthquake precursor information in many countries and regions. This paper briefly summarized the surface gravity observation technology and observation network in China: the surface gravity measurement instrument developed from Huygens physical pendulum in seventeenth Century to today’s high-precision absolute gravimeter, and its accuracy reached to ±1×10^-8 m/s². China has successively established the National Gravity Network, Digital Earthquake Observation Network of China,the Crustal Movement Observation Network of China Ⅰ and the Crustal Movement Observation Network of China, to provide a public platform for monitoring non tidal gravity change, seismic gravity and tectonic movement. The use of specific examples illustrated the role of gravity observation data in earthquake prediction. The gravity observation data of ground gravity can be used to capture the information of gravity change in the process of strong earthquake inoculation, and to provide an important basis for the long-term prediction of strong earthquakes. The temporal and spatial variation characteristics of the regional gravity field and its relation to strong earthquakes were analyzed: Before the earthquake whose magnitude is higher than M_S 5, generally there will be a large amplitude and range of gravity anomaly zones. Strong earthquakes occur mainly in areas where the gravity field changes violently. The dynamic change images of gravity field can clearly reflect the precursory information of large earthquakes during the inoculation and occurrence. Finally, the existing problems of surface gravity technology in earthquake precursor observation were put forward and the use of gravity measurement data in earthquake prediction research was prospected.     

Preliminary Results of In-situ Stress Measurements along the Longmenshan Fault Zone after the Wenchuan Ms 8.0 Earthquake

Four months after the Wenchuan Ms 8 earthquake in western Sichuan, China, in situ stress measurements were carried out along the Longmenshan fault zone with the purpose of obtaining stress parameters for earthquake hazard assessment. In-situ stresses were measured in three new boreholes by using overcoring with the piezomagnetic stress gauges for shallow depths and hydraulic fracturing for lower depths. The maximum horizontal stress in shallow depths (～20 m) is about 4.3 MPa, oriented NI9°E, in the epicenter area at Yingxiu Town, about 9.7 MPa, oriented N51°W, at Baoxing County in the southwestern Longmenshan range, and about 2.6 MPa, oriented N39°E, near Kangding in the southernmost zone of the Longmenshan range. Hydraulic fracturing at borehole depths from 100 to 400 m shows a tendency towards increasing stress with depth. A comparison with the results measured before the Wenchuan earthquake along the Longmenshan zone and in the Tibetan Plateau demonstrates that the stress level remains relatively high in the southwestern segment of the Longmenshan range, and is still moderate in the epicenter zone. These results provide a key appraisal for future assessment of earthquake hazards of the Longmenshan fault zone and the aftershock occurrences of the Wenchuan earthquake.     

汶川Ms8.0级地震断层同震位移特征对断裂构造分析的启示

断裂构造是地壳浅层次最重要的构造现象,也是构造地质学研究的主要领域之一.以稳态区域构造应力作用下的岩石变形破坏过程为基础的断裂构造分析理论和方法,受到强地震过程中断裂构造复杂同震变形的挑战.汶川Hs8.0级地震过程中断层同震变形的几何学、运动学特征及其空间变化,为检验断裂构造的几何学、运动学分析的相关理论和方法提供一个现实的范例.本文通过对汶川Ms8.0级地震断层同震位移的方式、规模和空间变化特征分析,提出沿断层走向的位移方式和位移规模的空间变化是区域构造应力和地震动力复合作用的结果.汶川地震过程中地震断层的位移方式和位移规模的空间变化以及同一构造部位的断层摩擦镜面中却出现了不同运动学指向的擦痕线理等特殊的构造现象,对历史断裂构造变形分析中所遵循的某些原则提出了挑战,需要重新审视和研究.     

Study on the Sliding Displacement of a Sliding Structure Subjected to Multi-directional Earthquake Excitation

The investigation of sliding isolation is mainlyfocused on the response of a structure subjected to asingle directional earthquake excitation. Fan andTang (2001) studied the slide limited friction (S LF)base isolation system, using a sequential exponentialfriction model. Zhang and Cheng (2001) studied theisolated effect of a sliding bearing as a friction damp er. Xiong and Yu (2002) studied the numerical meth od of sliding isolation system. But studying a singlecomponent of e…     

Preliminary Results of In‐situ Stress Measurements along the Longmenshan Fault Zone after the Wenchuan Ms 8.0 Earthquake

Abstract: Four months after the Wenchuan Ms 8 earthquake in western Sichuan, China, in situ stress measurements were carried out along the Longmenshan fault zone with the purpose of obtaining stress parameters for earthquake hazard assessment. In-situ stresses were measured in three new boreholes by using overcoring with the piezomagnetic stress gauges for shallow depths and hydraulic fracturing for lower depths. The maximum horizontal stress in shallow depths (~20 m) is about 4.3 MPa, oriented N19°E, in the epicenter area at Yingxiu Town, about 9.7 MPa, oriented N51°W, at Baoxing County in the southwestern Longmenshan range, and about 2.6 MPa, oriented N39°E, near Kangding in the southernmost zone of the Longmenshan range. Hydraulic fracturing at borehole depths from 100 to 400 m shows a tendency towards increasing stress with depth. A comparison with the results measured before the Wenchuan earthquake along the Longmenshan zone and in the Tibetan Plateau demonstrates that the stress level remains relatively high in the southwestern segment of the Longmenshan range, and is still moderate in the epicenter zone. These results provide a key appraisal for future assessment of earthquake hazards of the Longmenshan fault zone and the aftershock occurrences of the Wenchuan earthquake.     

基于Newmark模型的概率地震滑坡危险性模型参数优化与应用:以鲁甸地震区为例

应用概率地震危险性评价模型进行地震滑坡危险性区划,是解决潜在地震诱发滑坡危险性评价中震源不确定性与诱发滑坡时空不确定性的有效方法 .通过理论分析,结合鲁甸地震区的实际情况,对基于力学原理的Newmark滑块位移模型与概率地震滑坡危险性分析方法中的参数的不确定性问题进行了分析,将斜坡岩土体地震作用下的强度衰减效应、地震加速度地形放大效应、断层破碎带效应融合到了斜坡累积位移计算模型中,进行了模型计算参数的优化.改进后的分析模型,更好地反映了高陡斜坡地形与断层破碎带对地震滑坡灾害发育的控制作用,在鲁甸地震区域滑坡应用中,优化模型中的滑坡失稳极高风险区与实际地震滑坡分布表现出了较好的一致性,在超越概率2%的滑坡失稳概率分布中,鲁甸地区包谷垴-小河断裂、鲁甸-昭通断裂带及牛栏江河谷地带地震滑坡高-极高风险区分布面积增幅十分显著.因此,在Newmark滑块位移模型中考虑地震动参数与岩土参数动态响应规律与变量间的定量关系,对于提高区域斜坡稳定性分析的可靠性具有重要意义.