Collaborative Research: Holocene Tropical Cyclone Variability in the Western North Atlantic

飓风造成的损失在上个世纪显著增加，主要是沿海人口、城市化和财富增加的结果。最近卡特里娜、艾琳和桑迪飓风的影响凸显了美国在热带气旋面前的脆弱性。 不幸的是，北大西洋西部飓风发生的仪器记录很短（约160年），这大大阻碍了人们对调节飓风活动的驱动机制的理解。 此外，飓风在任何特定地区登陆的相对罕见性进一步限制了从已经有限的数据集中提取有意义的模式。这个合作项目由伍兹霍尔海洋研究所和德克萨斯农工大学加尔维斯顿分校的研究人员进行，旨在将飓风活动的记录追溯到数千年前，并在沿海下沉洞和蓝洞中保存了飓风通过的沉积证据。在强烈的飓风袭击期间，风暴潮和波浪会动员和运输沙子和砾石等粗沉积物。这些粗沉积物中的一部分作为一个层保存在通常沉积在沉降孔和蓝孔中的细粒沉积物中。这些粗粒层可以用来重建数千年来的史前风暴事件，在整个时间内，沉洞和蓝洞一直在收集沉积物。目前的工作重点是从巴哈马和牙买加的地点建立这些过去热带气旋活动的长期记录。这些记录将补充来自佛罗里达狭长地带和美国东北部的现有记录，并将有助于阐明热带气旋活动的空间和时间模式，并允许检查这种变化的气候驱动因素。这项工作的更广泛影响包括更全面地了解过去几千年来影响飓风活动的一系列气候因素。这种对自然变化的更好的洞察力对于为建模工作提供信息和评估这些风暴的未来风险至关重要。该项目还将提供一个平台，通过本科生和研究生阶段的实际动手跨学科研究经验，培训下一代地球科学家。

Damage from hurricanes has increased markedly over the last century, largely the result of increased coastal population, urbanization and wealth. The recent impacts of hurricanes Katrina, Irene, and Sandy highlight the vulnerability of the United States to tropical cyclones. Unfortunately, the short instrumental record of hurricane occurrence (~160 years) in the western North Atlantic significantly hampers efforts to understand the driving mechanisms responsible for modulating hurricane activity. Additionally, the relative rarity of hurricane landfalls at any particular region further limits the extraction of meaningful patterns from an already limited data set. This collaborative project, conducted by researchers at the Woods Hole Oceanographic Institution and Texas A&M University at Galveston, is aimed at extending the record of hurricane activity back thousands of years with sedimentary evidence of hurricane passage preserved in coastal sink holes and blue holes. During an intense hurricane strike, storm surge and waves mobilize and transport coarse sediment such as sand and gravel. Some of this coarse sediment is preserved as a layer in the finer grained sediments normally deposited in sink holes and blue holes. These coarse grained layers can be used to reconstruct prehistoric storm events over the thousands of years, throughout the time sink holes and blue holes have been collecting sediments. This current work is focused on developing these long-term records of past tropical cyclone activity from sites in the Bahamas and Jamaica. These records will complement existing records from the panhandle of Florida and the Northeastern US and will help elucidate spatial and temporal patterns in tropical cyclone activity and allow for the examination of the climatic drivers of this variability.Broader impacts of the work include a more comprehensive understanding of the array of climate factors that influence hurricane activity over the past several millennia. This improved insight into natural variability is essential to inform modeling efforts and assess future risks from these storms. The project will also provide a platform for training the next generation of geoscientists through practical, hands-on interdisciplinary research experiences at the undergraduate and graduate level.