Doctoral Dissertation Research: Proxy Records of Paleohurricane Activities for the Western and Southern Caribbean

博士论文研究：西加勒比和南加勒比古飓风活动的代理记录

• 批准号: 0602554
• 负责人: Kam-biu Liu
• 金额: $ 1.18万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0602554&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Proxy; Records

This project aims to establish the geological proxy records of hurricane activities in the western and southern parts of the Caribbean region. Shifts in the location of hurricane tracks occur across a variety of scales, from interannual to millennial. The damage hurricanes inflicted upon the United States during the 2004 and 2005 seasons dramatically demonstrates the societal importance of such shifts. The goal of this doctoral dissertation research project is to identify the climatic forcing mechanisms responsible for these shifts by correlating long-term climate and hurricane histories. Such a correlation has not heretofore been possible due to gaps in the paleohurricane record, particularly from the oft-struck Caribbean region. This study attempts to close this gap by obtaining proxy hurricane records from sediment cores from coastal sites in Belize, Nicaragua and Barbados. Major hurricanes (category 3 or greater) typically leave an identifiable sedimentary signature in coastal lakes and swamps by transporting recognizable beach and marine material, such as sand and marine organisms, inland where it is deposited onto more organic material. A comprehensive history of hurricane landfalls extending thousands of years into the past can be determined by counting and dating these hurricane-generated layers. Present evidence indicates dramatic changes in landfall frequency for the Gulf Coast on timescales of centuries to millennia, driven by changes in atmospheric circulation. This study will help delineate the temporal and spatial extent of these changes by extending sedimentary studies to the far southern Caribbean. Past climate conditions will be ascertained from a pollen analysis conducted on the cores and from published records, while laboratory analyses of magnetic susceptibility, electric resistivity, organic content, and grain size will be used to identify hurricane-generated layers. Chronological control will be by radiocarbon dating. Extending the proxy hurricane record to unstudied Caribbean areas will facilitate a clearer understanding of long-term hurricane behavior on a regional basis, while connecting the hurricane and climatic records will improve our understanding of the relationship between the two. Investigating hurricane activity as an interactive component of the larger circulation patterns facilitates untangling the complex connections. Since property damage and loss of life in the Caribbean and the United States resulting from the shift in the frequency and location of hurricane paths since the mid 1990s has been tremendous, any increased understanding of the mechanisms controlling the location and frequency of landfall will be of great societal value. The clarification of the role hurricanes play in the North Atlantic climate system and the way these relationships respond to changing climatic conditions is a critical step towards developing an effective societal response to this serious natural hazard.

该项目旨在在加勒比地区西部和南部建立飓风活动的地质代理记录。飓风轨道位置的变化发生在各种尺度上，从年届到千禧一代。 2004年和2005年季节，美国对美国造成的损害极大地证明了这种转变的社会重要性。该博士学位论文研究项目的目的是通过将长期气候和飓风历史相关联，确定导致这些转变的气候强迫机制。由于古尿路记录中的差距，尤其是来自经常拉克的加勒比地区，这种相关性并非迄今为止。这项研究试图通过从伯利兹，尼加拉瓜和巴巴多斯的沿海地区的沉积物核心获取代理飓风记录来缩小这一差距。主要的飓风（3级或更高）通常通过运输可识别的海滩和海洋物质（例如沙子和海洋生物），在沿海湖泊和沼泽中留下可识别的沉积物签名，并将其沉积在更多有机材料上。飓风登陆的综合历史可以通过计算和约会这些飓风生成的层来确定数千年的过去。目前的证据表明，由于大气循环的变化，墨西哥湾沿岸的登陆频率发生了巨大变化。这项研究将通过将沉积研究扩展到最南部的加勒比海，帮助描述这些变化的时间和空间范围。从核心和已发表的记录进行的花粉分析将确定过去的气候条件，而对磁敏感性，电阻率，有机含量和晶粒尺寸的实验室分析将用于鉴定飓风生成的层。按时间顺序控制将通过放射性碳年代进行。将代理飓风记录扩展到未研究的加勒比地区将有助于更清楚地了解长期的飓风行为，同时将飓风和气候记录联系起来将提高我们对两者之间关系的理解。将飓风活动作为较大循环模式的互动组成部分进行研究，促进了复杂连接的障碍。由于自1990年代中期以来飓风路径的频率和位置的变化，加勒比海和美国的财产损失和生命损失是巨大的，因此对控制登陆位置的机制和频率的任何理解都将具有巨大的社会价值。阐明飓风在北大西洋气候系统中所扮演的角色以及这些关系对不断变化的气候条件的反应方式是迈向建立对这种严重自然危害的有效社会反应的关键一步。