The tsunami and cyclone hazard in Myanmar - Surveying coastal geoarchives for sedimentary evidence of extreme wave events

缅甸的海啸和气旋灾害 - 调查沿海地质档案以获取极端波浪事件的沉积证据

基本信息

批准号：
299338813
负责人：
Dr. Dominik Brill
金额：
--
依托单位：
Geographisches Institut
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2017-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/299338813?language=en
关键词：
tsunami cyclone hazard Myanmar Surveying

项目摘要

Since at least the 2004 Indian Ocean Tsunami (IOT) the benefits of geological tsunami evidence are well established. Although the IOT 2004 also had an exceptional magnitude, its catastrophic effects can only be explained by missing awareness concerning the tsunami risk of the region. Being the first tsunami of this dimension on instrumental and historical records, only geological evidence could have provided information on predecessor events to raise awareness and trigger vulnerability-reducing measures. This example and similar observations after tropical cyclone (TC) Nargis 2008 in Myanmar or Supertyphoon Haiyan 2013 in the Philippines demonstrate that robust hazard assessment must be based on the occurrence of extreme wave events (EWE) with different magnitudes over a prolonged time. While frequency-magnitude information from modern and historical TCs and tsunamis in SE Asia is restricted to a few centuries, geological imprints potentially cover periods of several millennia and record EWE with exceptional magnitudes and low frequencies.While the IOT 2004 triggered intensive research in most affected areas, still very little is known about EWE deposits in Myanmar. In consequence, the long-term hazard due to exceptional TCs and tsunamis is poorly constrained, although Myanmar is exposed to coastal flooding from three major sources: (i) eastward-moving TCs generated in the Bay of Bengal (e.g. TC Nargis); (ii) tsunamis triggered by complete ruptures of the North-Sumatra-Andaman segment of the Sunda Arc (e.g. the IOT 2004); and (iii) tsunamis triggered by ruptures of the Rakhine (Arakan) segment offshore western Myanmar (e.g. the 1762 tsunami). Since the lack of investigations is at least partly the result of a limited research activity due to the political isolation of Myanmar during the last decades, we assume that geological evidence of EWE is present in suitable near-shore geoarchives; these can contribute to an improved understanding of the long-term tsunami and cyclone hazard.While the preconditions for the proposed research are provided by a cooperation between Yangon and Cologne Universities, the possibility of poorly preserved or scarce EWE deposits advises a survey of several sites rather than a systematic investigation of individual locations. Therefore, 6-8 beach-ridge plains along the coasts of Myanmar shall be surveyed using light equipment for levelling (DGPS) and sampling (trenches, push cores) of EWE landforms (storm ridges, washover fans) and sand sheets. In combination with sedimentological (granulometry, fauna, mineralogy, geochemistry) and chronological (radiocarbon, optically stimulated luminescence) laboratory analyses the proposed survey shall trigger follow-up projects by (i) providing a basis for the systematic investigation of promising sites; and (ii) transferring knowledge to local graduates that participate in the field survey.

由于至少2004年印度洋海啸（IoT），地质海啸证据的好处已得到充分确立。尽管物联网2004也具有非凡的幅度，但它的灾难性影响只能通过缺少对该地区海啸风险的意识来解释。作为该维度关于工具和历史记录的第一个海啸，只有地质证据才能提供有关前身事件的信息，以提高意识并触发降低脆弱性的措施。在菲律宾的缅甸或超植物上的Haiyan 2013中，热带气旋（TC）NARGIS 2008之后的这个例子和类似观察结果表明，稳健的危害评估必须基于在延长时间内具有不同大小的极端波浪事件（EWE）的发生。虽然来自现代和历史的TCS和SE亚洲海啸的频率 - 磁性信息仅限于几个世纪，但地质烙印可能涵盖了几千年的几千年，并记录了具有出色幅度和低频的EWE时期。当IOT 2004年IOT 2004年受到的强烈研究触发了大多数受影响的地区，在大多数受影响的领域中，仍然很少知道Ewwe ewwe in myanmar in MyWew。因此，尽管缅甸暴露于三个主要来源的沿海洪水，但由于特殊的TC和海啸引起的长期危害受到限制：（i）在孟加拉湾产生的向东移动的TC（例如TC Nargis）；（ii）海啸由Sunda Arc的北 - 阵线和北部段的完全破裂引起（例如，IoT 2004）；（iii）海啸由若开邦（Arakan）段的破裂触发，缅甸西部西部（例如1762 Tsunami）。由于缺乏调查至少部分是由于缅甸在过去几十年中的政治隔离而导致的研究活动有限的结果，因此我们假设在适当的近岸地理结构中存在EWE的地质证据。这些可以有助于改善对长期海啸和旋风危险的理解。虽然Yangon和Cologne大学之间的合作提供了拟议研究的先决条件，但保存或稀缺的EWE押金的可能性建议对几个地点进行调查，而不是对单个位置进行系统的调查。因此，应使用轻型设备（DGPS）和样本（Trenches，Push cores）对缅甸海岸的6-8平原平原进行调查。结合沉积学（颗粒测量法，动物群，矿物学，地球化学）和年代学（放射性碳，光刺激的发光）实验室分析，该调查应通过（i）为有前途的站点进行系统研究的基础触发随访项目；（ii）将知识转移到参加现场调查的地方毕业生。