Collaborative Research: RAPID: Hurricane Ian's overwash deposit: impacts of high-intensity landfalling tropical cyclones in southwest Florida

热带气旋是影响美国海岸线的最危险和最昂贵的自然灾害之一。随着风暴特征的变化和气候变暖导致海平面上升，这些事件将产生更严重的影响。最近，佛罗里达西南部受到两次4级飓风的影响，分别是2017年的厄玛和2022年的伊恩。5年内同一地区发生的两次重大事件为研究这些风暴的地质数据提供了独特的机会。这一快速反应项目将通过收集与“伊恩”飓风风暴潮和沉积物存款有关的地质数据，探讨高强度飓风的影响。此外，之前在2017年和2019年对飓风伊尔玛的研究将允许对这两个最近的事件进行比较。这种多风暴焦点将有助于了解飓风对西南佛罗里达海岸的影响。这些数据还将进一步增加有关保护地质沉积物免受反复风暴影响的知识。这些数据对于改善对过去和现在风暴活动的了解至关重要。该项目通过支持一个由早期职业科学家以及本科生和研究生组成的全女性团队，在STEM领域取得了更广泛的代表性。为了扩展我们对过去热带气旋的理解，我们依靠地质记录重建了仪器记录时期以外的气旋强度和频率的历史。然而，重建热带气旋的地质记录依赖于对过冲沉积物及其在沿海环境中如何保存的现代模拟研究。本研究的目的是调查佛罗里达西南部的两个地点，方法是：1）测量陆地高程，记录飓风伊恩的过冲存款的厚度和向陆地的范围; 2）将伊恩的存款与之前的飓风（飓风厄玛）进行比较，后者也在2017年在整个佛罗里达西南部登陆并沉积沉积物。该项目是通过2017年和2019年的实地调查实现的，这些调查记录了佛罗里达西南部的飓风伊尔玛过冲沉积物。将采集样品进行沉积学（粒度和有机物含量）、地球化学（稳定碳同位素和C/N值）和微体化石（有孔虫）分析，以比较伊恩、伊尔玛和风暴前沉积物的地球化学指标。该项目的成果将通过确定关键的地球化学指标，并对受反复高强度飓风影响的地区飓风沉积物的保存潜力提供重要的见解，从而推进佛罗里达南部亚热带地区的古风暴研究。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Tropical cyclones are amongst the most dangerous and costly natural hazards to impact U.S. coastlines. These events will have worsening effects with changing storm characteristics and sea-level rise in a warming climate. Most recently, southwest Florida has been impacted by two Category 4 hurricanes, Irma in 2017 and Ian in 2022. Two major events in the same region within 5 years presents a unique opportunity to study geological data from these storms. This rapid response project will explore the impact of high-intensity hurricanes by collecting geological data related to Hurricane Ian’s storm surge and sedimentary deposit. Further, previous work on Hurricane Irma in 2017 and 2019 will allow for a comparison between these two recent events. This multiple storm focus will help to understand the impact of hurricanes across the southwest Florida coast. The data will also add further knowledge about the preservation of geological deposits from repeated storms. Such data are crucial to improve understanding of past and present storm activity. The project advances broader representation in STEM through support of an all-female team of early career scientists and as well as undergraduate and graduate students.To extend our understanding of past tropical cyclones, we rely on geologic records to reconstruct a history of cyclone intensity and frequency beyond the instrumental period. However, reconstructing geologic records of tropical cyclones relies on modern analog studies of overwash deposits and how they are preserved in coastal environments. The aim of this study is to investigate two sites in southwest Florida by 1) measuring land elevation and recording the thickness and landward extent of Hurricane Ian’s overwash deposit and 2) comparing Ian’s deposit with a previous hurricane (Hurricane Irma) which also made landfall and deposited sediments throughout southwest Florida in 2017. The project is enabled by previous field investigations in 2017 and 2019 which documented Hurricane Irma overwash sediments in southwest Florida. Samples will be collected for sedimentologic (grain-size and organic content), geochemical (stable carbon isotopes and C/N values), and microfossil (foraminifera) analyses to compare biogeochemical indicators from Ian, Irma, and pre-storm sediments. Results of this project will advance paleo-storm studies in the sub-tropical southern Florida region by identifying key biogeochemical indicators and providing critical insight into the preservation potential of hurricane deposits in areas impacted by repeated, high-intensity hurricanes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.