Tsunami backwash deposits on the Algarve continental shelf

海啸研究已经成为地球科学领域的重要研究领域，特别是在印度洋（2004年苏门答腊）和日本（2011年东北- oki）最近发生的海啸事件之后。这类事件是不可预测的、灾难性的，会对基础设施造成严重破坏和生命损失。因此，（古）海啸沉积物的沉积学分析已成为评估沿海社区海啸风险的关键因素，并最终有助于减轻影响。尽管海啸科学和沉积学领域在过去几十年中取得了长足的进步，但许多海啸特征和相关过程，特别是海啸反冲流的水动力学，仍然知之甚少。在这个项目中，我们喜欢调查在M152号（RV METEOR）巡航期间，在垂直于葡萄牙阿尔加维海岸的两个横断面上采集的离岸约80米的岩心，通过多代理方法，包括沉积学，地球化学，年代测定和古生物学。工作包包括：a)确定合适的代用物，以表征阿尔加维陆架近海沉积物中海啸沉积物的特征，直至约100米水深；B)确定近海海啸沉积物的潜在沉积物来源（如海滩、沙丘、近岸），c)重建运输路径，以实现陆上和海上海啸沉积物特征的比较；最后，d)绘制海啸反冲沉积物沿阿尔加维陆架的空间分布，包括巡航期间获得的水声数据。这些数据对于海啸从海岸向近海反冲的水动力过程的后期建模是必需的。由于Algarve受到AD1755年里斯本海啸的强烈影响，并且可能在3.7 kyr之前发生过一次更早的事件，并且我们已经在沉积物岩心中确定了事件，因此我们的目标是综合大陆架的数据。我们的科学假设包括开发用于历史和史前海啸的工具，以帮助检测和评估全球近海海啸事件，并建立反冲沉积物分布模式的一般模型。

Tsunami research has become prominent within geosciences, especially following the recent tsunami events in the Indian Ocean (2004 Sumatra) and in Japan (2011 Tohoku-Oki). Events like these are unpredictable, catastrophic and responsible for severe damages to infrastructures and loss of lives. Consequently, the sedimentological analysis of (palaeo)tsunami deposits has become a key factor for the evaluation of tsunami risk to coastal communities and can eventually help to mitigate impacts. Even though the field of tsunami science and sedimentology showed substantial progress during the last decades, many tsunami characteristics and related processes, especially regarding the hydrodynamics of tsunami backwash flows, are still poorly understood. In this project, we like to investigate offshore c. 80 m of cores taken in two transects perpendicular to the Algarve coast off Portugal during cruise M152 (RV METEOR) by vibracoring by a multiproxy approach including sedimentology, geochemistry, dating and palaeontology. Work packages include the a) identification of suitable proxies for the characterisation of tsunami deposits in the offshore deposits of the Algarve shelf until ca. 100 m water depth; b) the determination of potential sediment sources (e.g., beach, dune, nearshore) for the offshore tsunami deposits, c) the reconstruction of the transport paths to achieve a comparison of the characteristics of onshore and offshore tsunami deposits; and lastly, d) the mapping of the spatial distribution of tsunami backwash deposits along the Algarve shelf including hydroacoustic data obtained during the cruise. These data are needed for a later modelling of hydrodynamic processes of tsunami backwash from the coast towards the offshore. As the Algarve was intensely affected by the AD1755 Lisbon tsunami, and, probably an earlier event ca. 3.7 kyr ago, and we already identified the events in sediment cores, we aim to synthesize the data of the shelf. Our scientific hypotheses include the development of tools for historical and prehistoric tsunamis that helps to detect and evaluate these events off-shore world-wide and to set up general models for distribution modes of back wash sediments.