Key Processes in the Holocene Evolution of Tropical Coasts - Evaluating the Role of Hurricanes and Tsunamis

作为一个位于半干旱热带的珊瑚岛，博内尔(荷属安的列斯群岛)非常适合作为研究极端事件记录的生物和地理档案馆。存储在堡垒、碎石山脊、巨石田野等地的这些特征可以通过14C-AMS和ESR以高精度很好地确定日期。此外，博内尔的泻湖体系和近岸湖泊包含了大约30年来连续的沉积记录。距今6000年。该项目旨在确定博内尔热带石灰岩海岸及其生态系统全新世演化的驱动力。将突发和高强度极端事件(飓风和海啸)的影响比作稳定、连续和低强度(非极端)的形成过程。为了实现这一目标，通过对近岸地质档案中沉积岩心的分析和对陆上粗沉积物的研究，破译了这两种过程类型的全新世历史。地质年代学框架由ESR和放射性碳测年法建立。沿海生态系统(珊瑚礁、红树林)在适应/再生、相变或灭绝方面对极端事件的反应是该项目的一个重要组成部分。近岸生物地理档案存储海洋和陆地记录。他们的相互关系将用多代理的方法来研究。总体而言，我们的目标是将博内尔岛建立为热带海岸的原型区域，在那里极端事件是海岸演变的关键过程。

Being a coral island situated in the semi-arid tropics, Bonaire (Netherlands Antilles) is excellently suited as bio- and geoarchive for studying the record of extreme events. Alt such signatures stored in ramparts, rubble ridges, boulder fields, etc. are well datable by 14C-AMS and ESR with high precision. Moreover, Bonaire's lagoonal systems and near shore lakes contain continuous sedimentary records since approx. 6000 yrs BP. The project aims to identify the driving forces responsible for the Holocene evolution of Bonaire's tropical limestone coast and its ecosystems. The impact of sudden and high-magnitude extreme events (hurricanes and tsunamis) is compared to steady, continuous and low-magnitude (non-extreme) forming processes. To achieve this goal the Holocene history for both process types is deciphered by the analysis of sediment cores in near shore geoarchives and the study of coarse deposits onshore. The geochronological framework is built by ESR and Radiocarbon dating. The response of the coastal ecosystems (coral reefs, mangroves) to extreme events in terms of adaptation/regeneration, phase shifts or extinction is a vital component of the project. Near shore bio-geoarchives store marine and terrestrial records. Their interrelationship will be studied with a multi-proxy approach. Overall, we aim to establish the island of Bonaire as a prototype region for tropical coasts where extreme events act as key processes in the coastal evolution.