基于地壳形变监测数据的地震危险性研究

发布时间：2018-05-17 05:25

本文选题：地壳形变 + 监测　；参考：《中国矿业大学(北京)》2017年博士论文

【摘要】：环太平洋地震带和欧亚地震带是世界上两大著名的地震带,我国位于这两大地震带的交汇部位,夹持在印度板块、太平洋板块以及菲律宾板块之中,受印度板块的挤压作用和太平洋板块俯冲作用的影响,晚第四纪和现代构造活动强烈,地震灾害频发。研究表明,构造活动与地震的孕育密切相关,许多强震主要是由逆断层和走滑断层产生,正断层的规模一般较小,其所产生的地震规模也较小。活动地块运动是中国大陆在晚新生代和现代的构造变形主要特征,地块边界主要为活动断裂带、活动褶皱带和活动盆地带;并且活动块体通过边界带的构造变形来对强震起着控制作用,各活动边界的地震水平受控于其自身构造活动速率。总体表现为,我国西部地震活动水平高于东部。地壳形变测量为研究地壳变形及其与地震之间的关系提供了重要的技术手段,并且提供了具有明确物理意义的直接证据。本文从跨断层场地监测得到的直观的断层运动特征出发,以1973年Savage等人提出的螺旋位错模型为基础,以鲜水河断裂带为例分析了跨断层形变测量得到的近场断层运动特征,并比较其与InSAR形变场得到的断层空间运动特征的一致性,从地震矩均衡与断层滑动亏损角度估计了断层的地震危险性,结合固体潮汐形变测量异常分析与识别方法提出了基于多种方法的地壳形变监测模式。主要取得研究成果如下:(1)跨断层形变测量作为一种监测地壳形变的方法,通过观测断层附近范围内跨断层点位间的相对位移变化来研究断层的运动特征。本文在前人研究基础上提出了基于平面直角坐标的断层运动学参数计算方法,以鲜水河断裂带跨断层场地测量资料为例比较了两种断层运动学参数计算方法的差异,两种方法得到的计算结果基本一致。从断层运动学参数计算方法和遇到的问题出发,提出了跨断层场地布设的优化方式。(2)在螺旋位错模型基础上推导出了近场断层运动位错模型公式,通过近场的跨断层场地基线变化揭示其所跨断层部位的深部闭锁信息,计算结果表明鲜水河断裂带上老乾宁场地闭锁深度达到了18km,其余场地闭锁深度均较浅,并根据断层基线速率变化利用形变测量数据估计了断层闭锁时间。(3)利用SBAS-InSAR时序分析方法研究震间构造变形信息。利用SBAS-InSAR时序分析方法得到的空间形变场揭示了鲜水河断裂带的左旋走滑运动性质;选取横跨断层的15条剖面,计算发现断层两侧的形变运动特征符合文中推导出的近场断层运动模型,闭锁深度计算结果与跨断层测量的计算结果均反映了鲜水河断裂带北西段的浅闭锁特征,二者具有很好的一致性;利用螺旋位错模型进行拟合得到鲜水河断裂带北西段左旋走滑速率为10mm/a左右;提出了分层位错模型,解释了断裂带的浅闭锁特征;计算断层滑动引起的累积地震矩和研究区内1700-2016年以来M≥5.0以上地震的地震矩释放量,得到研究区断层的滑动亏损进而分析研究区地震危险性,综合多种研究成果分析认为乾宁段存在强震的危险。(4)与跨断层测量、InSAR、GPS观测相比,固体潮汐形变测量具有更高的观测精度,能够观测到其所在位置微小变化。文中以固体潮汐形变观测数据出现的异常变化为例,说明定点形变观测中异常核实、信息提取与判定方法,利用集中载荷模型分析了库容变化对地倾斜观测影响,并提出了基于水位变化改正伸缩应变数据的计算方法,对定点形变观测布局提出一些建议。(5)综合上述研究成果,从观测精度、空间分辨率和时间分辨率角度分析了不同观测方法的优势,提出了基于多种观测方法的地壳形变监测模式,为科学合理布局地壳形变监测网络提供研究基础。
[Abstract]:The Pacific seismic belt and the Eurasian seismic belt are the two most famous seismic belts in the world. Our country is located at the intersection of the two major seismic belts. It is held in the India plate, the Pacific plate and the Philippines plate. It is influenced by the extrusion of the India plate and the subduction of the Pacific plate, and the late Quaternary and modern tectonic activities are strong. The earthquake disaster occurs frequently. The study shows that the tectonic activity is closely related to the inoculation of the earthquake. Many strong earthquakes are mainly caused by the reverse fault and the strike slip fault. The scale of the normal fault is generally small and the scale of the earthquake is small. The movement of the active block is the main feature of the tectonic deformation of the late Cenozoic and the modern in the mainland of China, and the main boundary is the main boundary. The active fault zone, active fold belt and active basin zone, and the active block is controlled by the tectonic deformation of the boundary zone, and the seismic level of each active boundary is controlled by its own tectonic activity rate. Form and its relationship with earthquakes provide important technical means, and provide direct evidence with clear physical significance. This paper, based on the spiral dislocation model proposed by Savage et al. In 1973, analyzes the cross fault pattern based on the feature of the visual fault motion obtained from the monitoring of the cross fault site. The characteristics of the near-field fault motion obtained by variable measurement are compared, and the consistency of the spatial motion characteristics of the fault is compared with the InSAR deformation field. The seismic hazard of the fault is estimated from the angle of seismic moment equilibrium and the fault slip loss, and the crustal deformation monitoring based on a variety of methods is put forward in combination with the method of anomaly analysis and recognition of the solid tide deformation measurement. The main achievements are as follows: (1) cross fault deformation measurement is used as a method of Monitoring Crustal deformation, and the motion characteristics of the fault are studied by observing the relative displacement changes between the faults in the vicinity of the fault. Based on the previous research, a fault kinematic parameter meter based on the plane right angle coordinates is proposed. The calculation method, taking the survey data of the cross fault site in the fresh water river fault zone as an example, compares the difference of the calculation methods of the kinematic parameters of the two kinds of faults, and the results obtained by the two methods are basically the same. From the calculation method of the kinematic parameters of the fault and the problems encountered, the optimization method for the layout of the cross fault site is put forward. (2) the spiral dislocation model is used. On the basis of this, the model formula of the near field fault dislocation model is derived, and the deep interlocking information of the cross fault location is revealed through the change of the baseline of the cross fault site in the near field. The calculation results show that the locking depth of the old dry Ning site on the fresh water river fault zone reaches 18km, and the rest of the site is shallow, and the change of the base line rate varies according to the fault baseline rate. The time of fault locking is estimated with the deformation measurement data. (3) using the SBAS-InSAR time series analysis method to study the structural deformation information between earthquakes. The spatial deformation field obtained by the SBAS-InSAR time series analysis method reveals the left-slip movement property of the fresh water river fault zone, and selects 15 sections across the fault to calculate the deformation transport on both sides of the fault. The dynamic characteristics conformed to the near field fault motion model derived from the paper, and the calculation results of interlocking depth calculation and cross fault measurement all reflect the characteristics of shallow atresia in the north west section of the fresh water river fault zone. The two ones have good consistency, and the levospin strike slip rate of the North west section of the fresh water river fault zone is 10mm/ by using the spiral dislocation model. The stratified dislocation model is proposed to explain the shallow atresia characteristics of the fault zone, the cumulative seismic moment caused by the fault slip and the earthquake moment release of more than 5 earthquakes over 1700-2016 years in the study area for 1700-2016 years in the study area, and the slip loss of the fault in the study area is obtained, and the seismic risk of the study area is analyzed. There is a danger of strong earthquakes in the dry Ning section. (4) compared with the cross fault measurement, InSAR, GPS observation, the solid tide deformation measurement has a higher observation precision and can observe the small change in its location. In this paper, the abnormal changes in the observed data of the solid tide deformation data are taken as an example, and the anomaly verification in the observed fixed point deformation observation, the information extraction and the decision are made. Method, using the concentrated load model, the influence of the change of storage capacity on the ground tilt observation is analyzed, and a calculation method based on the correction expansion strain data of the water level is proposed, and some suggestions are put forward for the observation layout of the fixed point deformation. (5) the results of the above research are integrated, and the different observations are analyzed from the observation accuracy, the space resolution and the time resolution. Based on the advantages of the method, a monitoring model of crustal deformation based on various observation methods is put forward to provide scientific basis for scientific and rational layout of crustal deformation monitoring network.
【学位授予单位】：中国矿业大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：P227;P315.7

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