English  |  正體中文  |  简体中文  |  Items with full text/Total items : 28611/40649
Visitors : 624621      Online Users : 68
RC Version 4.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Adv. Search
LoginUploadHelpAboutAdminister

Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/24869

Title: 加瓜海脊地殼速度構造的海底地震儀&多頻道震測資料分析
Crustal Velocity Structure across the Gagua Ridge from OBS and MCS Data
Authors: 鄧家明;陳鼎仁;王天楷;李昭興;劉家瑄
Contributors: NTOU:Institute of Applied Geosciences
國立臺灣海洋大學:應用地球科學研究所
Keywords: 海底地震儀
Micro-Ocean-Bottom Seismometers (MicrOBS)
Date: 2008
Issue Date: 2011-10-20T08:17:57Z
Publisher: 中華民國地質學會&中國地球物理學會九十七年年會暨學術研討會
Abstract: 2006年9月,我們使用達觀艦從西向東橫跨北呂宋島弧、花東海盆、加瓜海脊與西菲律賓海盆約224公里的測線施放十座輕巧型海底地震儀,並以海研一號接收24頻道的反射震測資料。本研究先利用反射震測資料和重力反演的密度模型建立沉積層與地殼初始模型,然後選取海底地震儀水壓與垂直分量資料的首波、折射波與反射波走時,以剝層法反演沉積與地殼速度模型。從沉積層P波速度模型顯示加瓜海脊的東側海槽與花東海盆沉積層厚度分別約為3公里與4公里厚。至於地殼P波速度模型則顯示加瓜海脊地殼約為14公里厚,而其東西兩側的地殼則分別為7公里和10公里厚。我們也發現加瓜海脊兩側(4.4~5.4公里/秒)與花東海盆(4.2~5.2公里/秒)基盤的P波速度變化大、加瓜海脊的地殼速度(4.8~6.5 公里/秒)高於其附近的上部地殼速度(4.4~5.6 公里/秒),且與北呂宋島弧東側地殼有一明顯的速度分界。我們認為加瓜海脊的東西兩側及花東海盆下方皆有斷層帶,且海脊東西兩側的地殼構造是不對稱的,因此本研究支持前人所提:加瓜海脊是因菲律賓海板塊西北方向聚合擠壓而隆起。
Ten Micro-Ocean-Bottom Seismometers (MicrOBS) and a Multi-Channel Seismic (MCS) profiling were implemented across the Gagua Ridge in September 2006. First, an initial model was built from reflection times of the MCS data and a density model inverted from gravity data. Subsequently, we picked refracted and reflected arrivals from four-component OBS data to invert the velocity-interface structure layer-by-layer. Sedimentary model based on OBS/MCS data shows that the largest thickness of the Huatung Basin and the Eastern Trough of Gagua Ridge are about 4 km and 3 km, respectively. Two thrust faults, one west dipping about 45 degrees beneath the Eastern Trough and another east dipping 60 degrees beneath the Western Trough, are imaged in the active basement near the Gagua Ridge. East of the Gagua Ridge, the small velocity variation but with large velocity (about 5.5~6.0 km/s) of the upper crustal structure is observed whereas the large velocity variation but with small velocity (about 3.5~5.0 km/s) is found west of the Gagua Ridge. We also observed from the OBS model that the crust is thicker about 14 km thick below the Gagua Ridge, but it remains about 9~10 km thick as the normal oceanic crust on the both sides of the Gagua Ridge. We conclude that the asymmetrical structures west and east of the Gagua Ridge and formation of the Gagua Ridge within the oceanic crust imaged from OBS data may have resulted from compression due to the northwest convergence of the Philippine Sea Plate east of Gagua Ridge.
Relation: O1-B19
URI: http://ntour.ntou.edu.tw/handle/987654321/24869
Appears in Collections:[應用地球科學研究所] 演講及研討會

Files in This Item:

File Description SizeFormat
index.html0KbHTML104View/Open


All items in NTOUR are protected by copyright, with all rights reserved.

 


著作權政策宣告: 本網站之內容為國立臺灣海洋大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用,請合理使用本網站之內容,以尊重著作權人之權益。
網站維護: 海大圖資處 圖書系統組
DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback