2013-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/710500摘要：本計畫延續去年所提之多年期研究，主要利用地震學方法研究高加索地區之速度構造及地震特性，同時加強過去西藏高原的研究，藉由對比來探討大陸碰撞的岩石圈演化。西藏與高加索分別位於東亞與西亞，其板塊碰撞的背景相似:西藏-喜瑪拉雅造山帶是印度板塊向北擠壓與歐亞板塊產生劇烈碰撞後所形成的巨大高原，為大陸碰撞的經典範例；高加索山則為阿拉伯板塊與歐亞板塊碰撞的最北緣，連接著伊朗高原及向西構造逃脫的土耳其，至今該區域的研究仍然很少又很複雜。申請人過去主要研究西藏下方之岩石圈構造，發現地殼由南往北變薄、羌塘地塊下的地函速度異常及西藏岩石圈剝離卻可能含水等現象，最新研究不但證實大尺度的構造為真，還顯示拉薩地殼中有數個地層低速異常。高加索研究也有初步成果，甫獲台大補助購置之數台地震儀已經陸續架設於野外，地震資料蒐集分析正在進行。本計畫若能繼續獲得國科會支持，高加索(喬治亞與亞美尼亞)地震網得以維護建構，有利跨國、跨領域的合作，本年度將著重在地函非均向性及與高加索地殼構造，以了解岩石圈地函是否有隱沒。<br> Abstract: We propose to continue our study of the velocity structure and earthquake properties beneath Caucasus region, which is located north of Iranian plateau in the western Asia. This mountain belt marks the northern boundary of the collision between Arabia and Eurasia. We conduct study mainly based on our extensive work completed for Tibet. The tectonic context between the Caucasus-Zagros and Tibetan-Himalayan mountain belts is their similarities in the history of continental collision. For example, the speed of convergence in Caucasus-Zagros is smaller and initiated later, with similar strike-slip features on the surface indicating lateral extrusion in the eastern Turkey. Evidences above make it an interesting target for further investigation. However, little seismic constraints are available in Caucasus. New observations are desired to make important contributions. In our previous work, we found crustal thickness is thinner and the upper mantle velocity is slower in the northern Tibet. We also discovered seismic anomalies that may be associated with a delamination of Tibetan lithospheric mantle and the detached lithosphere might be hydrous. In the proposed study, we aim to examine the structure in detail under Tibet, which serves as a high-quality basis for comparison. More importantly, we plan to use 3-year period to expand the network in Caucasus and explore the seismic properties of the crust and upper mantle there. As the end of 2012, the deployment of seismic stations in Caucasus is in good progress and pre-existing data are analyzed. We also detect low velocity layers in Tibet. In the proposal, we added a component regarding to mantle anisotropy. We hope NSC can continue the support. Such contrasting study of Caucasus and Tibet are important for our understanding to the controlling factors of evolution during collision and the dynamic interactions between the involving plates.西藏高加索大陸碰撞地震波非均向性接收函數地殼地函震源機制解TibetCaucasuscontinental collisionseismic anisotropyreceiver functionscrustupper mantlefocal mechanism