青藏高原巖石圈低速結(jié)構(gòu)的動力學(xué)模型
發(fā)布時間：2018-08-07 09:03
【摘要】：青藏高原是研究巖石圈形成演化,探討地殼運(yùn)動機(jī)制的理想?yún)^(qū)域。自新生代以來,青藏高原的隆升及其對周邊地區(qū)氣候與資源的深刻影響,一直為科學(xué)界所矚目,成為國際上地球科學(xué)的研究熱點(diǎn)。研究青藏高原的動力學(xué)機(jī)制,對揭示地球上生態(tài)演化規(guī)律和人類文明發(fā)展具有重要的科學(xué)意義。相比于其它現(xiàn)代大地測量技術(shù),如GPS、InSAR和衛(wèi)星重力技術(shù),用地面重力數(shù)據(jù)研究青藏高原的動力學(xué)機(jī)制能夠提供與其它大地測量技術(shù)互補(bǔ)的物質(zhì)遷移信息,比如,能夠探測到GPS和InSAR技術(shù)難以觀測到的地球深部物質(zhì)運(yùn)動信號,與常用的GRACE衛(wèi)星重力數(shù)據(jù)相比對地球局部淺層質(zhì)量的形變遷移更加靈敏,能夠捕獲地震波層析成像技術(shù)難以捕捉到的深部物質(zhì)的動態(tài)運(yùn)動信號。巖石圈結(jié)構(gòu)的(剪切波)低速結(jié)構(gòu)通常被認(rèn)為是強(qiáng)度較低的部分,因此在印度-歐亞板塊的碰撞過程中更容易發(fā)生形變,理論上更容易產(chǎn)生顯著的重力變化信號。本文的研究思路就是提取巖石圈低速結(jié)構(gòu)在歐亞-印度板塊碰撞過程中引起的地面重力信號,并建立利用提取到的重力變化信號研究深部物質(zhì)遷移的理論和方法,將提取的重力信號與地震波層析成像模型(即青藏高原巖石圈結(jié)構(gòu))對比尋找兩者的相關(guān)性,聯(lián)合多種數(shù)據(jù)構(gòu)造和分析青藏高原的動力學(xué)模型。以往缺乏類似的研究,本文提出系統(tǒng)的研究方法和理論,主要內(nèi)容總結(jié)如下：(1)提出聯(lián)合地面重力數(shù)據(jù)、地表位移觀測數(shù)據(jù)和巖石圈速度結(jié)構(gòu)模型研究青藏高原動力學(xué)機(jī)制的策略。研究了提取上地幔重力變化信號的方法,收集其它各類數(shù)據(jù)和模型,從總重力變化信號中改正和扣除各種不關(guān)心的重力變化信號分量。(2)在各種重力變化分量中,重點(diǎn)研究了估計(jì)地殼應(yīng)變引起的重力變化,構(gòu)建了相應(yīng)的數(shù)學(xué)模型,利用地面GPS水平速度計(jì)算面應(yīng)變,然后用面應(yīng)變計(jì)算重力變化。(3)將青藏高原的地面重力測站劃分為22個子區(qū)域,計(jì)算它們的上地幔重力變化、面應(yīng)變和地表垂向位移,用于定量分析和輔助構(gòu)建青藏高原的局部區(qū)域動力學(xué)模型。根據(jù)地表位移、巖石圈速度結(jié)構(gòu)和提取的上地幔重力變化,本文提出相應(yīng)的動力學(xué)模型,概括如下：(1)青藏高原北部存在一個大尺度的低速結(jié)構(gòu),這些低強(qiáng)度物質(zhì)形成一個倒三角形狀,很可能在印度-歐亞碰撞過程中上涌,在遇到地殼下表面以后沿莫霍面水平向擴(kuò)散,由此形成青藏高原北部大范圍的正重力變化信號。(2)青藏高原內(nèi)陸的正重力變化在南部呈現(xiàn)一個突起,幾何形態(tài)與地表拉張斷層走向十分符合,表明與地表結(jié)構(gòu)的形成具有密切的聯(lián)系。本文傾向于認(rèn)為是印度板塊撕裂的結(jié)果。具體地,印度板塊俯沖到歐亞板塊下撕裂,板塊裂隙被自北向南擴(kuò)散的上地幔物質(zhì)填充,引起正重力變化。(3)祁連山北部的低速結(jié)構(gòu)對應(yīng)一個明顯的負(fù)重力變化信號,可能是由于低速結(jié)構(gòu)受到南北向擠壓下沉侵入地幔中形成。(4)青藏高原東南部巖石圈中存在多個低速結(jié)構(gòu),包括位于中-下地殼(26°N緯線以北)的兩個低速帶和位于上地幔(26°N緯線以南)的一個低速結(jié)構(gòu)。本文認(rèn)為26°N緯線以北的兩個低速帶是受到松潘-甘孜塊體向南運(yùn)動的擠壓而增厚,形成正重力變化信號；26°N緯線以南的低速結(jié)構(gòu)遵循Airy均衡調(diào)整的動力學(xué)模型,并釋放青藏高原的重力勢能。(5)青藏高原東南部的條帶狀低速結(jié)構(gòu)延伸至龍門山斷裂西南端,這里的中-下地殼低速構(gòu)造受到擠壓增厚,上地殼由于四川盆地的阻擋受到擠壓和增厚,兩者的共同作用導(dǎo)致龍門山斷裂帶西南端抬升。龍門山斷裂帶東北端的地殼受到擠壓、縮短而堆積侵入地幔。因此,龍門山兩端的重力勢能差增大,并且方便兩端之間的斷層走滑運(yùn)動,引發(fā)地震(如2008年汶川地震和2013年蘆山地震)。
[Abstract]:The Qinghai Tibet Plateau is an ideal region to study the formation and evolution of the lithosphere and to explore the mechanism of the crustal movement. Since the Cenozoic, the uplift of the Qinghai Tibet Plateau and its profound influence on the climate and resources in the surrounding areas have been attracting the attention of the scientific community and becoming a hot spot in the international research of earth science. Compared with other modern geodetic techniques, such as GPS, InSAR and satellite gravity technology, the dynamic mechanism of the Qinghai Tibet Plateau can provide material migration information complementary to other geodetic techniques, such as the detection of GPS and InS, compared with other modern geodetic techniques. AR technology is difficult to observe the motion signal of the earth's deep material. Compared with the common GRACE satellite gravity data, it is more sensitive to the deformation and migration of the shallow layer of the earth, and can capture the dynamic motion signal of the deep material which is difficult to capture by the seismic wave tomography. The rock structure (shear wave) low velocity structure is usually recognized. As a part of the lower strength, it is easier to deform in the collision process of the India Eurasian plate, and it is easier to produce significant gravity change signals in theory. The force change signal studies the theory and method of the deep material migration, and compares the extracted gravity signal with the seismic wave tomography model (that is the lithosphere structure of the Qinghai Tibet Plateau) to find the correlation between the two, to combine various data to construct and analyze the dynamic model of the Qinghai Tibet Plateau. The main contents of the method and theory are summarized as follows: (1) the strategy of combining ground gravity data, ground displacement observation data and lithosphere velocity structure model to study the dynamic mechanism of the Qinghai Tibet Plateau is proposed. The method of extracting gravity change signals from upper mantle is studied, other kinds of data and models are collected and corrected and deducted from the total gravity change signals. Various signal components of gravity change that are not concerned. (2) in various gravity variation components, the gravity change caused by the estimation of the crustal strain is studied. A corresponding mathematical model is constructed. The surface strain is calculated by the horizontal velocity of the ground GPS, then the surface strain is used to calculate the gravity change. (3) the ground gravity station of the Qinghai Tibet Plateau is divided into 22 sub stations. The region, the gravity variation of the upper mantle, the surface strain and the vertical displacement of the surface are used for quantitative analysis and auxiliary construction of the local regional dynamic model of the Qinghai Tibet Plateau. Based on the surface displacement, the velocity structure of the lithosphere and the gravity change of the upper mantle, the corresponding dynamic models are proposed, which are summarized as follows: (1) the Northern Qinghai Tibet Plateau There is a large scale low velocity structure, which forms an inverted triangle shape. It is likely to surge up in the India Eurasia collision course and spread horizontally along the Moho surface after the surface of the earth's crust, thus forming a wide range of positive gravity change signals in the Northern Qinghai Tibet Plateau. (2) the positive gravity change in the inland of the Qinghai Tibet Plateau is The southern part presents a protruding, which is in close agreement with the direction of the surface stretching fault, indicating that it is closely related to the formation of the surface structure. This article tends to be considered the result of the tearing of the India plate. Specifically, the India plate subducts to the Eurasian plate and is torn under the Eurasian plate, and the plate fissure is filled with the upper mantle material spreading from north to south. (3) the low velocity structure in the northern part of Qilian Mountains corresponds to a significant negative gravity change signal, which may be due to the formation of the low velocity structure under the North-South extrusion and subsidence. (4) there are several low velocity structures in the lithosphere southeast of the Qinghai Tibet Plateau, including two low velocity zones and positions located in the middle lower crust (26 degree N weft North). It is a low velocity structure in the upper mantle (26 degree N weft South). This paper considers that two low speed belts north of the 26 N weft are thickened by the Songpan Ganzi block southward movement, forming a positive gravity change signal, and the low-speed structure in the south of the 26 degree N weft follows the dynamic mechanical model of the equilibrium adjustment of the Airy and releases the gravitational potential energy of the Qinghai Tibet Plateau. (5) the low-speed structure in the southeast of the Qinghai Tibet Plateau extends to the southern end of the Longmen mountain fault, where the low-speed structure of the middle and lower crust is squeezed and thickened, the upper crust is squeezed and thickened by the obstruction of the Sichuan basin. The joint action of the Sichuan basin leads to the uplift of the southwest end of the Longmen mountain fault zone. The crust in the northeast of the Longmen mountain fault zone is squeezed. The pressure, shortening and accumulation invades the mantle. Therefore, the gravitational potential difference between the two ends of the Longmen mountain increases, and facilitates the strike slip motion between the two ends, causing earthquakes (such as the Wenchuan earthquake of 2008 and the Lushan earthquake in 2013).
【學(xué)位授予單位】：武漢大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：P542
本文編號：2169541
[Abstract]:The Qinghai Tibet Plateau is an ideal region to study the formation and evolution of the lithosphere and to explore the mechanism of the crustal movement. Since the Cenozoic, the uplift of the Qinghai Tibet Plateau and its profound influence on the climate and resources in the surrounding areas have been attracting the attention of the scientific community and becoming a hot spot in the international research of earth science. Compared with other modern geodetic techniques, such as GPS, InSAR and satellite gravity technology, the dynamic mechanism of the Qinghai Tibet Plateau can provide material migration information complementary to other geodetic techniques, such as the detection of GPS and InS, compared with other modern geodetic techniques. AR technology is difficult to observe the motion signal of the earth's deep material. Compared with the common GRACE satellite gravity data, it is more sensitive to the deformation and migration of the shallow layer of the earth, and can capture the dynamic motion signal of the deep material which is difficult to capture by the seismic wave tomography. The rock structure (shear wave) low velocity structure is usually recognized. As a part of the lower strength, it is easier to deform in the collision process of the India Eurasian plate, and it is easier to produce significant gravity change signals in theory. The force change signal studies the theory and method of the deep material migration, and compares the extracted gravity signal with the seismic wave tomography model (that is the lithosphere structure of the Qinghai Tibet Plateau) to find the correlation between the two, to combine various data to construct and analyze the dynamic model of the Qinghai Tibet Plateau. The main contents of the method and theory are summarized as follows: (1) the strategy of combining ground gravity data, ground displacement observation data and lithosphere velocity structure model to study the dynamic mechanism of the Qinghai Tibet Plateau is proposed. The method of extracting gravity change signals from upper mantle is studied, other kinds of data and models are collected and corrected and deducted from the total gravity change signals. Various signal components of gravity change that are not concerned. (2) in various gravity variation components, the gravity change caused by the estimation of the crustal strain is studied. A corresponding mathematical model is constructed. The surface strain is calculated by the horizontal velocity of the ground GPS, then the surface strain is used to calculate the gravity change. (3) the ground gravity station of the Qinghai Tibet Plateau is divided into 22 sub stations. The region, the gravity variation of the upper mantle, the surface strain and the vertical displacement of the surface are used for quantitative analysis and auxiliary construction of the local regional dynamic model of the Qinghai Tibet Plateau. Based on the surface displacement, the velocity structure of the lithosphere and the gravity change of the upper mantle, the corresponding dynamic models are proposed, which are summarized as follows: (1) the Northern Qinghai Tibet Plateau There is a large scale low velocity structure, which forms an inverted triangle shape. It is likely to surge up in the India Eurasia collision course and spread horizontally along the Moho surface after the surface of the earth's crust, thus forming a wide range of positive gravity change signals in the Northern Qinghai Tibet Plateau. (2) the positive gravity change in the inland of the Qinghai Tibet Plateau is The southern part presents a protruding, which is in close agreement with the direction of the surface stretching fault, indicating that it is closely related to the formation of the surface structure. This article tends to be considered the result of the tearing of the India plate. Specifically, the India plate subducts to the Eurasian plate and is torn under the Eurasian plate, and the plate fissure is filled with the upper mantle material spreading from north to south. (3) the low velocity structure in the northern part of Qilian Mountains corresponds to a significant negative gravity change signal, which may be due to the formation of the low velocity structure under the North-South extrusion and subsidence. (4) there are several low velocity structures in the lithosphere southeast of the Qinghai Tibet Plateau, including two low velocity zones and positions located in the middle lower crust (26 degree N weft North). It is a low velocity structure in the upper mantle (26 degree N weft South). This paper considers that two low speed belts north of the 26 N weft are thickened by the Songpan Ganzi block southward movement, forming a positive gravity change signal, and the low-speed structure in the south of the 26 degree N weft follows the dynamic mechanical model of the equilibrium adjustment of the Airy and releases the gravitational potential energy of the Qinghai Tibet Plateau. (5) the low-speed structure in the southeast of the Qinghai Tibet Plateau extends to the southern end of the Longmen mountain fault, where the low-speed structure of the middle and lower crust is squeezed and thickened, the upper crust is squeezed and thickened by the obstruction of the Sichuan basin. The joint action of the Sichuan basin leads to the uplift of the southwest end of the Longmen mountain fault zone. The crust in the northeast of the Longmen mountain fault zone is squeezed. The pressure, shortening and accumulation invades the mantle. Therefore, the gravitational potential difference between the two ends of the Longmen mountain increases, and facilitates the strike slip motion between the two ends, causing earthquakes (such as the Wenchuan earthquake of 2008 and the Lushan earthquake in 2013).
【學(xué)位授予單位】：武漢大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：P542
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 劉杰;方劍;李紅蕾;崔榮花;陳銘;;青藏高原GRACE衛(wèi)星重力長期變化[J];地球物理學(xué)報(bào);2015年10期
2 Zhen J.Xu;Xiaodong Song;Sihua Zheng;;Shear velocity structure of crust and uppermost mantle in China from surface wave tomography using ambient noise and earthquake data[J];Earthquake Science;2013年05期
3 祝意青;聞學(xué)澤;孫和平;郭樹松;趙云峰;;2013年四川蘆山Ms7.0地震前的重力變化[J];地球物理學(xué)報(bào);2013年06期
4 ;Long-term gravity changes in Chinese mainland from GRACE and ground-based gravity measurements[J];Geodesy and Geodynamics;2011年03期
5 申重陽;李輝;孫少安;劉少明;玄松柏;談洪波;;重力場動態(tài)變化與汶川M_s8.0地震孕育過程[J];地球物理學(xué)報(bào);2009年10期
6 李輝;申重陽;孫少安;王曉權(quán);項(xiàng)愛民;劉少明;;中國大陸近期重力場動態(tài)變化圖像[J];大地測量與地球動力學(xué);2009年03期
7 ;Azimuthal anisotropy of Rayleigh waves beneath the Tibetan Plateau and adjacent areas[J];Science in China(Series D:Earth Sciences);2008年12期
8 石耀霖;朱守彪;;用GPS位移資料計(jì)算應(yīng)變方法的討論[J];大地測量與地球動力學(xué);2006年01期
9 王幼平;青藏高原隆起與東亞舊石器文化的發(fā)展[J];人類學(xué)學(xué)報(bào);2003年03期
10 江在森,馬宗晉,張希,王琪,王雙緒;GPS初步結(jié)果揭示的中國大陸水平應(yīng)變場與構(gòu)造變形[J];地球物理學(xué)報(bào);2003年03期
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