本文選題：并行計(jì)算　切入點(diǎn)：地震波模擬　出處：《中國(guó)地震局蘭州地震研究所》2015年碩士論文

【摘要】：隨著計(jì)算機(jī)技術(shù)的發(fā)展,單核心的超級(jí)計(jì)算機(jī)已經(jīng)逐漸退出人們的視野,被越來越多的廉價(jià)并行計(jì)算機(jī)所取代。并行計(jì)算技術(shù)的逐漸壯大為科技、工業(yè)、生活帶來了翻天覆地的變化。地球物理行業(yè)一直依賴于大規(guī)模計(jì)算技術(shù)的發(fā)展,本文選擇了地震學(xué)中最典型的兩個(gè)問題,借助中國(guó)地震局蘭州地震研究所的計(jì)算機(jī)集群,開展了關(guān)于地震波正反演的研究工作。本文的第一部分工作是運(yùn)用譜元法研究地震波的正演模擬。震后的災(zāi)害評(píng)估一直是地震局所關(guān)心的問題,對(duì)于臺(tái)站稀少的地區(qū),想要在震后根據(jù)臺(tái)站記錄勾畫出峰值分布變得異常困難。本文研究了譜元法的基本原理,借助普林斯頓大學(xué)的SPECFEM程序,以岷縣漳縣地震為例,展示了三維全波形地震波模擬對(duì)災(zāi)害評(píng)估的可行性。建立這樣的模擬平臺(tái)不僅僅可以用于災(zāi)后模擬評(píng)估,也可以用于破壞的預(yù)估計(jì),為城市規(guī)劃做出貢獻(xiàn)。本研究的第二部分工作,也是本論文的重點(diǎn),是關(guān)于地殼各向異性的研究。長(zhǎng)期以來,人們把工作的重心放在上地幔,而忽略地殼的各向異性。一方面是由于地殼的各向異性極其復(fù)雜,另一方面是由于將研究上地幔各向異性的方法移植到地殼研究時(shí)會(huì)遇到困難。本文詳細(xì)的對(duì)比了三種利用接收函數(shù)研究地殼各向異性的方法.由于加權(quán)疊加法和橫波分裂法在研究分層傾斜對(duì)稱軸各向異性問題時(shí)均存在局限性,本文重點(diǎn)以波形反演法展開研究。本文分析了各向異性參數(shù)和傾斜界面對(duì)波形的影響,并通過數(shù)值實(shí)驗(yàn)研究了反演的可靠性,提出通過二次反演改善反演結(jié)果的方法。本文的反演代碼根據(jù)raysum程序和鄰域算法重新構(gòu)建,并在程序中加入H-k約束,保證結(jié)果模型的有效性。文章的最后以青藏高原東北緣的16個(gè)臺(tái)站5年的資料為研究對(duì)象,嘗試著揭開青藏高原復(fù)雜的動(dòng)力學(xué)機(jī)制。通過對(duì)接收函數(shù)反演,發(fā)現(xiàn)在中下地殼確實(shí)存在著S波的低速層,這與中下地殼部分熔融的學(xué)說較為吻合。根據(jù)反演結(jié)果分析,發(fā)現(xiàn)上地殼各向異性基本滿足裂隙成因假說。如果中下地殼流的假說成立,那么可以很好的解釋本研究得到的中下地殼各向異性快軸的分布(東北緣地區(qū),在中地殼受到相鄰板塊的阻攔,在下地殼沿北東方向溢出)。本文的研究尚處于起步階段,揭示青藏高原的動(dòng)力學(xué)機(jī)制仍需要結(jié)合其他地球物理方法,本文的工作只是試圖通過各向異性的研究提供一些判據(jù)。
[Abstract]:With the development of computer technology, single core supercomputer has been gradually out of view and replaced by more and more cheap parallel computers.The development of parallel computing technology has brought about earth-shaking changes in technology, industry and life.The geophysics industry has been relying on the development of large-scale computing technology. In this paper, the two most typical problems in seismology have been selected, with the help of the computer cluster of Lanzhou Seismological Research Institute of China Seismological Bureau.The research on forward and inverse seismic wave modeling has been carried out.The first part of this paper is to use spectral element method to study forward modeling of seismic waves.The post-earthquake disaster assessment has always been of concern to the Seismological Bureau. It is extremely difficult to map out the peak distribution based on the station records for the regions where there are few stations after the earthquake.In this paper, the basic principle of spectral element method is studied. With the help of the SPECFEM program of Princeton University, taking the earthquake in Zhangzhou County, Minxian County as an example, the feasibility of 3D full-waveform seismic wave simulation for disaster assessment is demonstrated.Such a simulation platform can be used not only for post-disaster simulation assessment, but also for pre-estimation of damage, which can contribute to urban planning.The second part of this study, which is also the focus of this paper, is the study of crustal anisotropy.For a long time, the focus of work has been on the upper mantle, ignoring the anisotropy of the crust.On the one hand, the anisotropy of the crust is extremely complex, on the other hand, it is difficult to transplant the method of studying the upper mantle anisotropy to the crust.In this paper, three methods to study crustal anisotropy by receiving function are compared in detail.Due to the limitations of the weighted superposition method and the S-wave splitting method in studying the anisotropy of the stratified inclined symmetry axis, this paper focuses on the waveform inversion method.In this paper, the influence of anisotropic parameters and inclined interface on the waveform is analyzed, and the reliability of inversion is studied by numerical experiments, and a method to improve the inversion result by quadratic inversion is proposed.The inversion code of this paper is reconstructed according to raysum program and neighborhood algorithm, and H-k constraint is added to the program to ensure the validity of the result model.At the end of this paper, the data of 16 stations in the northeastern margin of the Qinghai-Xizang Plateau are taken as the research object, and the complex dynamic mechanism of the Qinghai-Xizang Plateau is tried to be revealed.By inversion of the receiving function, it is found that there is a low velocity layer of S wave in the middle and lower crust, which is in good agreement with the theory of partial melting of the middle and lower crust.According to the analysis of inversion results, it is found that the anisotropy of upper crust basically meets the hypothesis of fracture genesis.If the hypothesis of middle and lower crustal flow is established, the distribution of anisotropic fast axis of the middle and lower crust obtained in this study can be well explained (in the northeast margin, the middle crust is blocked by adjacent plates, and the lower crust overflows along the north and east direction.The study in this paper is still in its infancy, and it is still necessary to combine other geophysical methods to reveal the dynamic mechanism of the Qinghai-Xizang Plateau. This work only attempts to provide some criteria through the study of anisotropy.
【學(xué)位授予單位】：中國(guó)地震局蘭州地震研究所
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：P315.31-39

【引證文獻(xiàn)】

相關(guān)會(huì)議論文 前4條

1 高原;鄭斯華;馮德益;;剪切波的多級(jí)次分裂模式[A];1992年中國(guó)地球物理學(xué)會(huì)第八屆學(xué)術(shù)年會(huì)論文集[C];1992年

2 嚴(yán)珍珍;張懷;楊長(zhǎng)春;石耀霖;;汶川大地震地震波傳播的譜元法數(shù)值模擬研究[A];中國(guó)地球物理學(xué)會(huì)第二十四屆年會(huì)論文集[C];2008年

3 劉天啟;石耀霖;張懷;;汶川8.0級(jí)地震地震波傳播的三維有限元模擬[A];中國(guó)地球物理·2009[C];2009年

4 尹鳳玲;張懷;石耀霖;;日本東北地震波傳播并行有限元數(shù)值模擬及結(jié)果分析[A];中國(guó)地球物理學(xué)會(huì)第二十七屆年會(huì)論文集[C];2011年

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本文編號(hào)：1721909