本文選題：地震復(fù)發(fā)模型 + 高分辨率遙感影像　； 參考：《中國地震局地質(zhì)研究所》2016年博士論文

【摘要】：55~60Ma以來,印度板塊與歐亞板塊發(fā)生碰撞形成了當(dāng)今世界最年輕也是海拔最高的青藏高原,GPS數(shù)據(jù)表明現(xiàn)今這兩大板塊之間的相對匯聚速率依然達到35~42mm/a,受此影響,在高原內(nèi)部及其周緣地震頻發(fā)。前人研究表明,青藏高原周緣及其內(nèi)部自南而北發(fā)育了一系列大型的活動斷裂帶:喜馬拉雅斷裂帶、喀喇昆侖-嘉黎斷裂帶、甘孜玉樹-鮮水河斷裂帶、東昆侖斷裂帶以及阿爾金斷裂帶等,這些斷裂帶將青藏高原劃分為拉薩塊體、羌塘塊體、巴彥喀拉塊體、柴達木塊體等,能夠產(chǎn)生地表破裂的高震級地震主要沿這些塊體邊界的斷裂帶發(fā)生,這些地震地表破裂的空間分布特征、破裂樣式、位移量分布模式等特征是研究斷層的同震活動性、沿斷層的力學(xué)特征、地震復(fù)發(fā)模式的直接證據(jù),這些自然形成的真實樣本也為驗證數(shù)值模擬結(jié)果的可靠性提供了對比的依據(jù),最近取得長足進步的高分辨率遙感技術(shù)也為獲得這些數(shù)據(jù)提供了可能,再結(jié)合活動構(gòu)造定量研究的其他手段,如利用斷錯地貌獲得斷層長期滑動速率,利用古地震方法獲得古地震復(fù)發(fā)序列等,根據(jù)這些信息就能對發(fā)震斷層的長期活動性進行綜合分析,進一步可以判定青藏高原上地殼變形行為、檢驗各種青藏高原運動學(xué)模型的可靠性。本博士學(xué)位論文通過分析地震復(fù)發(fā)模型和活動斷層長期滑動習(xí)性定量研究相關(guān)的構(gòu)造地貌、古地震、年代學(xué)和區(qū)域古氣候變化對地貌面年代約束以及遙感技術(shù)等方法,系統(tǒng)研究了1997年瑪尼地震和2010年玉樹地震地表破裂特征、構(gòu)造含義、長期滑動習(xí)性及復(fù)發(fā)模型,獲得了如下主要結(jié)論:通過利用震后獲取的最新的高分辨率衛(wèi)星影像(0.5m)對1997年瑪尼地震形成的地表破裂帶進行詳細填圖,我們得到了全面精確的地表破裂信息,地表破裂西起(35°3'12.81"N,86°10'52.36"E),東到(35°24'7.62"N,88°0'1.81"E),全長170km,總體走向76°,同時也得到了更為精確的破裂位置和清晰的破裂樣式,在此基礎(chǔ)上主要根據(jù)破裂走向變化的幾何特征將破裂分為7段,分別是瑪爾蓋茶卡湖西段、瑪爾蓋茶卡湖段、瑪爾蓋茶卡湖東段、朝陽湖段、朝陽湖東段、雙端湖東段、東端點段。沿破裂也發(fā)育了豐富的地表破裂樣式,指示了不同的構(gòu)造含義:在瑪爾蓋茶卡湖段,由于斷層走向發(fā)生明顯偏轉(zhuǎn),結(jié)合斷層兩盤左旋走滑的運動特征,形成了局部的張性彎曲,瑪爾蓋茶卡湖即位于張性區(qū)域的下降盤,在另一盤則形成了相對上升的綏加山以及一系列的正斷層陡坎1973年的mw6.9地震的震中也位于該區(qū)域附近,其具有的張性分量與局部構(gòu)造環(huán)境相一致。在震中附近的朝陽湖段,受強地面振動和滑坡共同作用在山麓地帶形成了垂直斷層走向的逆沖變形,這些變形樣式的形成主要受凍土控制。在朝陽湖東段北盤可以見到一系列的次級破裂,這些次級破裂和主破裂的夾角自西向東逐漸增大,這是由于破裂有在張性象限形成張性破裂的趨勢造成的。在破裂的東端點段則形成了非常復(fù)雜的破裂樣式,破裂走向在三聯(lián)點附近發(fā)生近90°的大角度偏轉(zhuǎn),在沿弧形的先存斷裂擴展后在尾端呈馬尾狀撒開,形成了瑪尼地震的尾端構(gòu)造,而沒有沿原走向繼續(xù)向東擴展,結(jié)合nubukik.的數(shù)值模擬結(jié)果可以發(fā)現(xiàn)之所以形成這樣的破裂樣式,是受先存斷裂分布,區(qū)域主應(yīng)力方向和破裂擴展速度等多種因素共同作用的。根據(jù)斷層兩側(cè)地貌標(biāo)志重建獲得沿斷層分布的210個位移數(shù)據(jù),位移量從2m到249.8m不等,這其中既包含了1997年地震的同震位移,也包含了古地震的累積位移。通過對比根據(jù)高分辨率衛(wèi)星影像進行位移重建獲得的沿斷層分布的最小位移量與前人利用insar得到的同震位移分布的結(jié)果,發(fā)現(xiàn)兩種方法獲得的位移分布具有一致性,以1997年地震的同震位移分布為標(biāo)準(zhǔn),對比古地震的位移分布,可以發(fā)現(xiàn)斷層活動存在最大為7米左右的特征位移的現(xiàn)象,根據(jù)河流階地的斷錯量和氣候變化的時間可以估算出瑪爾蓋茶卡斷裂的長期滑動速率大約為8mm/a,這個速率略低于東昆侖斷裂的其他部分,可能是由于有一部分形變分配給了其北側(cè)的鯨魚湖段;結(jié)合瑪尼地震7米左右的最大位移,推測瑪尼地震的復(fù)發(fā)周期為850~900a。根據(jù)高分辨率遙感影像結(jié)合實地調(diào)查,發(fā)現(xiàn)2010年玉樹地震產(chǎn)生了總長度約65km的地表破裂,西起自隆寶鎮(zhèn)南扎西才仁家附近(96.43863°e,33.22611°n),東至結(jié)古鎮(zhèn)南巴曲東岸禪古寺附近(97.04354°e,3.94768°n),破裂總體走向約300°,是一個以左旋走滑為主,略有逆沖分量的地震事件,最大左旋位移為2.4米。沿斷層形成了剪切破裂、張剪切破裂、擠壓剪切破裂、張性破裂、地震鼓包和高原凍土區(qū)特有的冰裂縫等破裂樣式,玉樹地震地表破裂帶整體上可劃分為長約31km的結(jié)古次級地表破裂帶和長約15km的結(jié)隆次級地表破裂帶,兩者呈左階羽列展布,最大左旋走滑位移量分別為2.4m和0.66m,之間無地表破裂段長約17km,對應(yīng)于Mw6.9和Mw6.4兩個次級地震事件,這一同震位移分布樣式與利用InSAR和地震破裂過程反演得出的結(jié)果相吻合。位于玉樹縣甘達村和石渠縣滿真村附近的三處河流階地斷錯地貌研究表明:甘孜玉樹斷裂玉樹段的長期滑動速率在9.7mm/a左右,這與川滇塊體北邊界其他段落的滑動速率協(xié)調(diào)一致,結(jié)合探槽中反應(yīng)的古地震事件記錄:記錄到距今9.5~9.1ka、7.5~5.3ka、4.8~3.9ka、2.7ka四次古地震事件,且震級也有變化,推測甘孜-玉樹斷裂玉樹段的復(fù)發(fā)行為更接近位移可變模型,即沿斷層走向的滑動速率保持一致,但每次地震的位移并不一致,這可能是由于區(qū)域構(gòu)造背景復(fù)雜,觸發(fā)因素較多造成的,但鑒于得到的古地震位移分布數(shù)據(jù)還很有限,目前初步推測復(fù)發(fā)行為更接近位移可變模型。
[Abstract]:Since 55~60Ma, the collisions between the India and Eurasian plates have formed the youngest and highest Qinghai Tibet Plateau in the world today. The GPS data shows that the relative convergence rate between the two plates is still up to 35~42mm/a. A series of large active fault zones have been developed from south to North: the Himalaya fault zone, the Karakoram Jiali fault zone, the Yushu - fresh water river fault zone in Ganzi, the East Kunlun fault zone and the Altun fault zone, which divide the Qinghai Tibet Plateau into Lhasa block, Qiangtang block, Bayan Kara block and Qaidam block. The high magnitude earthquakes that produce the surface rupture mainly occur along the fracture zones of the boundary of these blocks. The characteristics of the spatial distribution characteristics of the surface rupture, the pattern of rupture and the pattern of displacement distribution are the study of the seismicity of the faults, the mechanical characteristics of the faults, the direct evidence of the mode of earthquake recurrence, and the real samples of these natural forms. It also provides the basis for the verification of the reliability of the numerical simulation results. The high resolution remote sensing technology which has recently made great progress has also provided the possibility for obtaining these data, and then combined with other means of quantitative study of active tectonics, such as using the fault geomorphology to obtain the long-term slip rate of the fault, and using the paleo seismic method to obtain the ancient earthquake complex. According to these information, the long-term activity of the seismogenic faults can be analyzed synthetically, and the deformation behavior of the upper crust in the Qinghai Tibet Plateau can be determined and the reliability of the kinematic models of the Qinghai Tibet Plateau can be tested. The characteristics of the surface rupture of the mani earthquake and the Yushu earthquake of 2010 in 1997, the tectonic implications, the tectonic implications, the long-term sliding habits and the recurrence models are systematically studied, and the following main conclusions are obtained: the latest conclusions obtained by using the earthquake after the earthquake. High resolution satellite image (0.5m) is a detailed mapping of the surface rupture zone formed by the mani earthquake in 1997. We have obtained full and accurate surface rupture information. The surface rupture (35 3'12.81 "N, 86 degree 10'52.36" E), east to (35 24'7.62 "N, 88 degree 0'1.81" E), a full length 170km, and the overall trend of 76 degrees, also got a more accurate rupture position. Based on the geometric features of the rupture trend, the rupture is divided into 7 segments, which are the western section of the Ma's Cha Hu Lake, the Mary cap tea Ka Lake section, the eastern segment of the Ma's tea card lake, the Chaoyang Lake section, the east section of the Chaoyang lake, the east end of the double end lake, and the rich pattern of surface rupture along the rupture. The different tectonic implications are shown: in the mamgea tea Ka Lake section, the local tensionic bending is formed due to the obvious deflection of the fault strike and the movement characteristics of the two disks in the fault, which is the drop plate in the tensionic area, and the relatively rising suijia mountain and a series of positive fault steepness in the other. The epicenter of the mw6.9 earthquake in 1973 is also located near the region, with its tensional component consistent with the local tectonic environment. In the Chaoyang Lake section near the epicenter, the thrust deformation of the vertical fault is formed by the joint action of strong ground vibration and landslides in the Piedmont. The formation of these deformation styles is mainly controlled by frozen soil. A series of secondary breakages can be seen on the North plate of the eastern Lake, which gradually increases from west to East, due to the tendencies of tensile rupture in the tensile quadrant, and a very complex fracture pattern formed at the eastern end of the rupture, which is nearly 90 degrees near the triplet. In the large angle deflection, the tail end of the arc is spread at the end of the arc. The tail end structure of the mani earthquake is formed, but it does not continue to spread eastward along the original direction. Combining with the numerical simulation results of nubukik., it can be found that the fracture pattern is formed by the preexisting fracture distribution, the direction of the regional main stress and the rupture expansion. 210 displacement data distributed along the fault are reconstructed from 2m to 249.8m according to the landmarks on both sides of the fault, which includes the same earthquake displacement of the 1997 earthquake and the cumulative displacement of the ancient earthquake. The minimum displacement along the fault and the result of the same earthquake displacement distribution obtained by InSAR have been found. It is found that the displacement distribution obtained by the two methods is consistent. The distribution of the same earthquake displacement of the earthquake in 1997 is the standard. Compared with the displacement distribution of the ancient earthquake, it can be found that the characteristic displacement of the fault activity is about 7 meters maximum. It can be estimated that the long-term sliding rate of the MalG tea card break is about 8mm/a, which is slightly lower than the other parts of the East Kunlun fault, possibly due to some deformation distribution to the whale Lake section of the north side, and the maximum displacement of about 7 m in combination with the mani earthquake. The recurrence period of the mani earthquake was 850~900a. based on high resolution remote sensing images combined with field investigation. It was found that the Yushu earthquake produced a surface rupture of about 65km in total length in 2010, from the west of Zha Xi Zhan Ren's home (96.43863 e, 33.22611 n) from the west to the East to the eastern basqu East Bank Temple (97.04354 [97.04354], 3.94768 n). The overall strike is about 300 degrees, which is an earthquake event with the main left spin, a slight thrust component, and the maximum left rotation displacement of 2.4 meters. Along the fault, the fracture patterns such as shear rupture, tensile shear rupture, compression shear rupture, tensioning rupture, earthquake drums and plateau permafrost regions are formed, and the surface rupture zone of the Yushu earthquake is on the whole The subsurface rupture zone and the subsurface rupture zone of the long approximately 15km are divided into 31km and about 15km, and the maximum left slip displacement is 2.4m and 0.66M, and the no surface rupture segment is about 17km, which corresponds to the two secondary earthquakes of Mw6.9 and Mw6.4, which together with the pattern of seismic displacement distribution and the use of InSAR. The results of the seismic fracture process are consistent with the results obtained. Three river terrace fault geomorphology studies in Gan Da Village, Yushu county and Shiqu County, full of river terraces show that the long-term sliding rate of the Yushu section of Ganzi Yushu fault is about 9.7mm/a, which is consistent with the sliding rate of the other sections of the north boundary of the Sichuan Yunnan block and the reaction in the slots. The record of the ancient earthquake events: recorded to the four paleo earthquake events of 9.5~9.1ka, 7.5~5.3ka, 4.8~3.9ka and 2.7ka, and the magnitude of the earthquake changed. The recurrence behavior of the Yushu section of the Ganzi Yushu fault is conjectured to be closer to the displacement variable model, that is, the slip rate along the fault direction is consistent, but the displacement of each earthquake is not consistent, which may be due to the fact that the displacement of each earthquake is not consistent. This may be due to the fact that the displacement of the earthquake is inconsistent. The regional tectonic background is complicated and the trigger factors are caused by many factors. However, in view of the limited data on the distribution of ancient seismic displacement, it is preliminarily estimated that the recurrence behavior is more close to the variable displacement model.

【學(xué)位授予單位】：中國地震局地質(zhì)研究所
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：P315.2

【參考文獻】

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