【作者】 武艳强；

【导师】 江在森；

【作者基本信息】 中国地震局地震预测研究所 ， 固体地球物理， 2008， 硕士

【摘要】 随着现代科学技术的发展,大规模科学计算成为科学研究中不可缺少的一部分。另一方面,随着“中国地壳运动观测网络工程”的实施,GPS技术在地壳形变监测领域的应用越来越广泛,它为科研人员提供了高精度、大尺度、多维的地壳形变监测数据。GPS资料中包含丰富的信息,如地壳运动信息、地壳形变信息、各种噪声信息等等。所以,如何高效、快速的提取这些信息就显得尤为重要。本文正是从这种思路出发,首先进行高性能计算方法的研究,然后在GPS地壳形变信息提取中对这些方法进行应用。前者为技术储备部分,主要对MPI并行计算的矩阵类和相关高性能计算方法进行研究。后者为本文的主体部分,主要包括对涉及到的大地测量知识进行阐述、对应变计算的不同方法进行分析、对GPS时间序列进行分析、对区域地壳形变场进行分析。通过对高性能计算方法和GPS地壳形变信息提取方法的研究,得到了一些初步结果。1)、高性能计算方法的研究通过对并行计算中稠密矩阵问题的讨论,以矩阵求逆算法为例,介绍的全选主元并行算法和列选主元并行算法。当矩阵阶数为2500阶、进程数为8个时,两种算法的效率为0.7左右。同时介绍了PLAPACK软件包、PETSc软件包和TAO软件包等几个成熟的并行软件包.接下来,把并行计算方法应用于实际中,如应变场的计算过程、最小二乘配置时间序列信息提取过程等。通过并行方法的应用,使计算效率得到了很大的提高,特别是在实验数据的模拟应变计算过程中能够保证高效完成任务。2)、应变计算的不同方法分析该部分内容主要包括块体应变计算方法分析和大范围低频应变场计算方法分析。对于前者,通过利用李延兴公式、Savage公式和平面公式(高斯投影平面和兰勃脱投影平面)对模拟数据的应变计算,对比了不同参考面块体应变计算结果的差异。得到的初步结果是:随着区域的增大,平面结果与球面结果差异会逐渐增大,而与点位纬度没有必然的联系。另一方面,大范围低频应变场计算方法的分析也是该部分的重要组成部分。通过对低频应变计算方法的分析,提出了多面函数应变计算方法和最小二乘配置球面方法,同时对球谐函数方法进行了一定的改进(对经纬度顺序进行了调整)。通过对模拟数据应变场不同计算方法的对比,发现不同方法得到的应变场与理论值都非常接近,初步证明了几种方法在低频应变场计算过程中的有效性。3)、GPS时间序列分析首先,通过对最小二乘配置模型的研究及其在GPS时间序列中的应用,提取了不同频段的信息。该方法的优势如下:理论的严密性及功能的完备性,同时完成滤波和插值操作。另外,该操作还可以作为谱分析、小波变换等方法的预处理过程。其次,通过对GPS时间序列与地球自转关系的研究,发现它们在2004年存在同步趋势转折现象,同时研究了地球表面不同纬度地区由于地球自转变化而引起的惯性离心力变化情况。另外,给出了中国GPS连续站N分量转折情况的统计结果并讨论了GPS基线时间序列的转折情况。再次,通过对GPS时间序列空间信息分离方法的探讨,把块体运动分为刚性运动、应变贡献部分变形和非规则变形等。在对华北地区GPS连续站进行信息分离的基础上,发现各分量所占的比重有明显差异,其中第一部分比重最大,其余两部分比重相当。从与地震孕育关系的角度看,应变贡献部分变形和非规则变形与地震孕育的联系更紧密一些,它们反应了地震孕育过程的能量积累和震前的快速形变过程。最后,采用GPS时间序列与其子样的相关系数作为指标对GPS时间序列稳定性进行了分析。结果显示GPS时间序列中有效信息部分是非常稳定的,即使只有10%的数据仍然能获得较好的分析结果,因此少量的数据缺失并不会影响GPS时间序列的分析。4)、区域地壳形变分析首先,对全球板块运动进行了分析,分析中采用了多面函数拟合法和欧拉模型方法。通过对板块边界运动及变形状态的分析,讨论了全球板块运动的特点。其次,对中国大陆速度场和应变场的演化进行了研究,结果表明伴随着2001年昆仑山地震的发生,应变场进行了动态调整。在面应变调整方面,以经度91度为界西部表现为张性,东部表现为压性。在最大剪应变方面,高值区表现了由西向东迁移的特性。最后,通过对区域变形场的研究,讨论了新疆地区和南北带地区应变场的动态演化过程并分析了其特性。更多还原

【Abstract】 With the development of modern science and technology, large scale computing is more and more important to scientific research. On the other hand, with the establishment of“Crustal Movement Observation Network of China”, GPS technology has played a more significant role in the domain of crustal monitoring and it has provided high precision, large scale and multi-dimension data for the researchers. GPS data contain abundant information, such as crustal movement information, crustal deformation information and many kinds of noise information, so how to distill the information from GPS data in efficient and fast way is an important question.This paper is based on the idea of solving the above question and it contains 2 parts that the first one aims at high performance computing method and the second aims at the application of these methods in distilling crustal deformation information from GPS data. The fore part is the technique preparation and it includes the discussion of matrix class based on "Message Passing Interface" parallel computing and other relating high performance computing methods. On the other hand, the later part is the main body of this paper, which includes illuminating the relating geodesy knowledge, analyzing the different strain calculating methods, analyzing the GPS time-series and analyzing the crustal deformation field in local region. On the research of high performance computing methods and distilling crustal deformation information from GPS data, some primary results are obtained.1) The research of high performance computing methodBy the discussion of dense matrix in parallel computing, the parallel methods of whole pivot element and column pivot element are given in the matrix inversion operation. When the rank of matrix reaches 2500 and the number of processes reaches 8, the efficiencies of these 2 methods can reach 0.7. Meanwhile, some integrity parallel software, such as PLAPACK, PETSc and TAO, are introduced.Then, the parallel computing methods are used in practice, such as strain field calculating and distilling information from time-series using least square collocation. By using these parallel computing methods, the calculating efficiency increases to a great extent, especially in strain field calculating process with simulating data.2) The analysis of different stain calculating methodThe content of this part contains the analysis of block strain calculating methods and low frequency strain calculating methods. The fore content aims at the formula of Li Yanxing, the formula of Savage and the plane formula of Gauss projection and Lambert projection. By comparing the results of these 3 formulas using simulating data, the conclusion is that the difference between the sphere formula and plane formula increases when the area of points distribution increases and does not relate to the latitude changing of points.On the other hand, the main content of this part includes analyzing the low frequency strain calculating method too. The multi-surface function method and least square collocating method in sphere surface are proposed, and spherical harmonic method is adjusted in the sequence of longitude and latitude when analyzing low frequency strain calculating methods. By comparing of the result obtained by different methods using simulating data, the conclusion is that all the results are similar to the real strain field, so these different methods are validated.3) The analysis of GPS time-seriesFirst, by the research of the least square collocation model and its application in GPS time-series, some different frequency information is distilled. This method has some advantages, which include precise theory foundation, complete functions and can finish data filtering and interpolation at one time. On the other hand, this method can be used as the pretreatment process of spectroscopic analysis and wavelet transformation method. Second, on the analysis of earth rotation data and GPS time series, the transition phenomena can be found in 2004. Then, the centrifugal force distribution due to earth rotation variation is researched in different latitude zone. Meanwhile, the statistics result of north orientation of GPS time-series is given and GPS baseline time-series is discussed.Third, on the research of the method of GPS data separating, the block movement can be classed rigid movement, strain contribution deformation and irregular deformation. After separating information in Huabei region, it is found that the proportions are different. The rigid movement proportion is large and other two are equal small. Considering of earthquake preparation, strain contribution deformation and irregular deformation are relative to it closely and they reflect energy accumulation and fast deformation before earthquake.Last, this part analyzes the stabilization of GPS time-series using the correlation coefficient between the whole time-series and its sub-sample. The result shows that the valid information of GPS time-series is very stable, and the good result can be obtained using even 10% data, so a few data lacking does not affect the analysis result.4) The analysis of regional crustal deformationFist, this part analyses the global plate movement, which using multi-surface function method and Euler model. By the analysis of the movement and deformation of global plate, their characteristics are discussed.Second, the evolution of the velocity and strain field in Chinese mainland is researched, and the result shows that the strain field has adjusted after Kunlun earthquake. The mainly adjustment of area strain field is that it shows tensional characteristic on the west of 91 degree longitude and shows pressure characteristic on the east. On the other hand, the adjustment of maximum shear strain field is that high value zone removes from west to east.Last, on the research of deformation field in local region, the evolution of strain field in Xinjiang and North South seismic belt are discussed and the evolution characteristic are analyzed.更多还原