基于高分辨率声学探测的渤海海峡地貌及灾害地质研究

发布时间：2018-02-13 21:14

本文关键词： 高分辨率声学探测渤海海峡地貌灾害地质　出处：《中国海洋大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来随着海洋经济建设的高速发展，人类对海洋地质的调查与研究也进入高精度、大比例尺的阶段，对海底地形地貌及灾害地质探测精度的要求也越来越高，在这种地质背景下高分辨率声学探测技术得到广泛的应用与发展。本文以国家大调查专项在渤海海峡及邻近海域所采集的最新高精度单波束水深数据、高分辨率浅地层剖面数据及高分辨率侧扫声纳数据为依据，，结合历史资料及研究区独特的自然地理环境、水动力环境和区域地质背景等资料，对研究区的海底地貌及潜在灾害地质因素进行了详细的描述和分析。基于形态成因的原则对研究区海底地貌进行了分类，并对次一级特殊地貌形态进行了详细解译，构建了较为完善的研究区海域地貌体系，发现渤海海峡地貌类型丰富，主要包括海岸带地貌和陆架地貌两个二级地貌类型，其中研究区以陆架地貌为主，主要分为陆架侵蚀堆积平原和陆架侵蚀洼地两个三级地貌单元，地貌形态以潮流冲刷槽、沙波、潮流沙脊、浅滩、礁石群等次一级地貌为主，并在侧扫声图中有明显反映；通过分析影响渤海海峡地貌的控制因素发现构造的断裂和坳陷内营力控制着海峡的基本地貌格局；全球海平面的升降带来的海侵和海退对研究区早期地貌形态有重要影响；海峡中分布的强潮流作用力对海底产生的侵蚀和堆积作用是塑造近代海峡地貌的重要外营力因素；同时人类对环渤海经济圈的开发影响了渤海海峡海底地貌的演化和发育。另外通过分析高分辨率声地层剖面资料将渤海海峡自海底向下共分为T0（海底）、T1、T2、T3、T4等4个声学反射界面和SU1、SU2、SU3、SU4、SU5等5个声学地层单元，绘制了各个地层单元的等厚度分布图，发现SU1至SU4地层单元在老铁山水道海域均出现了不同程度的缺失，取而代之的是残留沉积物。最后对渤海海峡海域潜在的灾害地质因素进行了详细分析，分为侵蚀陡坎、冲刷槽、侵蚀洼地、岩礁、潮流沙脊、活动沙波、浅滩以及埋藏基岩面、浅层气和活动断层等几种类型。详细分析了各类灾害地质的分布特征及潜在危害，绘制了研究区灾害地质平面分布图。
[Abstract]:In recent years, with the rapid development of marine economic construction, human investigation and research on marine geology has entered into the stage of high accuracy and large scale, the requirements of submarine topography and geological exploration accuracy are also becoming higher and higher. In this geological background, high-resolution acoustic detection technology has been widely used and developed. In this paper, the latest high-precision single-beam bathymetric data collected in the Bohai Strait and its adjacent sea area by the National investigation Project are presented. Based on high resolution shallow stratigraphic profile data and high resolution side scan sonar data, combined with historical data and the unique natural geographical environment, hydrodynamic environment and regional geological background of the study area, etc. The submarine geomorphology and potential hazard geological factors in the study area are described and analyzed in detail. Based on the principle of morphological origin, the submarine geomorphology of the study area is classified, and the subprimary special geomorphology is interpreted in detail. A perfect geomorphological system in the sea area of the study area is constructed. It is found that the Bohai Strait is rich in geomorphological types, including coastal geomorphology and shelf geomorphology, in which the continental shelf landform is the main type in the study area. It is mainly divided into two third-grade geomorphologic units: shelf erosion accumulation plain and shelf erosion depression. The geomorphologic forms are mainly tidal current scour trough, sand wave, tidal current sand ridge, shoal, reef group and so on. Through the analysis of the controlling factors affecting the geomorphology of the Bohai Strait, it is found that the tectonic faults and the internal forces in the depression control the basic geomorphologic pattern of the strait, and the transgression and regression caused by the global sea level rise and fall have important effects on the early geomorphological morphology of the study area. The erosion and accumulation of the strong tidal current acting on the sea floor is an important external force factor in shaping the geomorphology of the modern straits. At the same time, the development of the economic circle around the Bohai Sea affected the evolution and development of the seabed geomorphology of the Bohai Strait. In addition, the Bohai Strait was divided into four sounds from the bottom of the sea by analyzing the high-resolution acoustostratigraphic profile data: T0 (T _ (1) T _ (1)) T _ (2) T _ (3) T _ (4) and so on. Five acoustic stratigraphic units, such as the academic reflection interface and the Su _ 1 / S _ 2 / S _ 3 / S _ 4 / S _ 5, etc. The isothickness distribution map of each stratigraphic unit is drawn, and it is found that the SU1 to SU4 stratigraphic units are missing in different degrees in the Laotieshan waterway. In the end, the potential geological hazard factors in the Bohai Strait were analyzed in detail, including erosion steep ridges, scour channels, eroded depressions, reefs, tidal ridges, active sand waves, shoals and buried bedrock. Several types of shallow gas and active fault are analyzed in detail, the distribution characteristics and potential hazards of various types of disaster geology are analyzed in detail, and the plane distribution map of disaster geology in the study area is drawn.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P714;P737.2;P736

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