RAPID: Measuring the distribution and character of sedimentary deposits resulting from Hurricane Ian in Southwest Florida

RAPID：测量佛罗里达州西南部飓风伊恩造成的沉积物的分布和特征

• 批准号: 2308838
• 负责人: Jeffrey Donnelly
• 金额: $ 9.97万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-15 至 2024-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2308838&HistoricalAwards=false
• 关键词: RAPID; Measuring; distribution; character; sedimentary

Tropical cyclones can cause significant change to the coastal zone by eroding and transporting sediments. These sediments can be deposited into coastal sinkholes and offshore blue holes allowing scientists to study long-term hurricane activity. However, it remains poorly understood how sediment transport and deposition can vary due to different storm characteristics. The landfall of Hurricane Ian along the southwest coast of Florida provides an opportunity to study how intense hurricanes move sediments in the coastal zone. Knowing more about storm impacts will help clarify long-term risks associated with hurricanes. This project will study sediment from coastal sinkholes and offshore blue holes in southwest Florida. These data will be used to determine where, how much, and what kind of sediment was deposited from the storm. The results of this study have important implications in terms of coastal response to intense storms. These storms may become more frequent in response to Anthropogenic climate change. More storms may further alter coastal carbon cycling and nutrient flow in marine ecosystems. The Broader Impacts for this project include documenting local flooding patterns and sediment transport pathways that resulted from the storm. This information may be used to identify hazards associated with similar storms in the future. In addition, the project will provide support for an early-career postdoctoral researcher as the lead PI, and students will also participate in the project. Both PIs will work closely with local educators and stakeholders to disseminate the results broadly to the general public.This RAPID response study will examine the geomorphic and sedimentological impacts of the passage of Hurricane Ian on coastal sinkholes and offshore blue holes and the adjacent seafloor. Tropical cyclones can cause significant change to the shorelines and coastal oceans by eroding and transporting sediments. Coastal sinkholes and offshore blue holes can act as natural sediment traps that archive evidence of tropical cyclone sediment transport and have thus been utilized to reconstruct long-term hurricane activity. However, it remains poorly understood how archived deposits vary spatially and how they are expressed in relation to hurricane characteristics (e.g., intensity, translation speed) as relatively few hurricanes have impacted sites with sinkhole reconstructions in recent history. Hurricane Ian presents an exceptional opportunity to assess the sedimentary structure and composition of event deposits in a number of sinkholes and offshore blue holes along the coast most heavily impacted by the storm (Sarasota to Naples). By characterizing recent, minimally reworked or degraded deposits from a hurricane of known characteristics (i.e., intensity, track, translation speed, size), scientists can better constrain how paleo-hurricane deposits are related to local storm intensity. Further, significant offshore particulate organic matter export occurred as a result of Ian based on spatially and temporally constrained plumes captured in satellite imagery. Blue hole sediment records in The Bahamas contain organic rich layers atop coarse sediment beds attributed to hurricane driven transport, but the causality of these organic carbon rich beds has never been directly linked to event deposits in sinkholes and blue holes. Given that the post-Ian organic matter plumes intersect many offshore blue holes and terrestrial sinkholes, this is an ideal place and time to test this hypothesis by assessing transport potential, settling time, and provenance in the wake of hurricanes. The results of this study will improve understanding of hurricane-induced sediment transport, which will provide context for identifying and interpreting event beds deposited in sinkholes and offshore blue holes. This work will also begin to quantify hurricane-induced offshore organic sediment flux and provenance, which has important implications for understanding long-term coastal carbon cycling in coastal areas prone to hurricane strikes.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.

热带气旋可通过侵蚀和输送沉积物而对沿海地区造成重大变化。这些沉积物可以沉积到沿海天坑和近海蓝洞中，使科学家能够研究长期的飓风活动。然而，人们对沉积物输送和沉积如何因不同的风暴特征而变化仍知之甚少。飓风伊恩沿着佛罗里达州西南海岸登陆，为研究强烈的飓风如何移动沿海地区的沉积物提供了机会。了解更多有关风暴影响的信息将有助于明确与飓风相关的长期风险。该项目将研究佛罗里达州西南部沿海天坑和近海蓝洞的沉积物。这些数据将用于确定风暴沉积的沉积物的位置、数量和类型。这项研究的结果对于沿海地区对强风暴的反应具有重要意义。由于人为气候变化，这些风暴可能会变得更加频繁。更多的风暴可能会进一步改变海洋生态系统中的沿海碳循环和养分流动。该项目的更广泛影响包括记录风暴造成的当地洪水模式和沉积物输送路径。该信息可用于识别未来与类似风暴相关的危险。此外，该项目还将为一名处于职业生涯早期的博士后研究员作为首席 PI 提供支持，学生也将参与该项目。两位 PI 将与当地教育工作者和利益相关者密切合作，向公众广泛传播研究结果。这项快速响应研究将研究飓风伊恩通过对沿海天坑、近海蓝洞和邻近海底的地貌和沉积学影响。热带气旋可通过侵蚀和输送沉积物而导致海岸线和沿海海洋发生重大变化。沿海天坑和近海蓝洞可以作为天然沉积物陷阱，记录热带气旋沉积物运输的证据，因此可用于重建长期飓风活动。然而，人们对存档沉积物如何在空间上变化以及它们如何与飓风特征（例如强度、平移速度）相关的表达方式仍然知之甚少，因为近代历史上影响天坑重建的地点的飓风相对较少。飓风伊恩提供了一个绝佳的机会来评估受风暴影响最严重的海岸（萨拉索塔到那不勒斯）的许多沉洞和近海蓝洞的沉积结构和事件沉积物的成分。通过描述已知特征（即强度、路径、移动速度、大小）的飓风最近的、经过最低限度改造或退化的沉积物，科学家可以更好地限制古飓风沉积物与当地风暴强度的关系。此外，根据卫星图像中捕获的空间和时间受限羽流，伊恩导致近海颗粒有机物大量输出。巴哈马的蓝洞沉积物记录在粗沉积层顶部含有丰富的有机层，归因于飓风驱动的运输，但这些富含有机碳的层的因果关系从未与天坑和蓝洞的事件沉积物直接相关。鉴于伊恩之后的有机物羽流与许多近海蓝洞和陆地天坑相交，这是通过评估飓风后的传输潜力、沉降时间和来源来检验这一假设的理想地点和时间。这项研究的结果将增进对飓风引起的沉积物迁移的理解，这将为识别和解释沉积在天坑和近海蓝洞中的事件床提供背景。这项工作还将开始量化飓风引起的近海有机沉积物通量和来源，这对于了解容易遭受飓风袭击的沿海地区的长期沿海碳循环具有重要意义。该奖项反映了 NSF 的法定使命，并被认为值得支持通过使用基金会的智力优点和更广泛的影响审查标准进行评估。