RAPID: Post-Hurricane Irma Erosion and Deposition in Coastal Embayments of Eastern St. John, U.S. Virgin Islands

快速：飓风“艾尔玛”后美属维尔京群岛圣约翰东部沿海海湾的侵蚀和沉积

• 批准号: 1762346
• 负责人: Derek Sawyer
• 金额: $ 5.28万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-10-15 至 2018-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1762346&HistoricalAwards=false
• 关键词: RAPID; Post; Hurricane; Irma; Erosion

St. John, Virgin Islands is a tropical island made up primarily of ash and debris from volcanic eruptions. It is exposed to major geohazards such as hurricanes and tsunamis. The bathymetry of the nearshore coast has a strong influence on the severity of runup and surge from such events. St. John and other similar volcanic islands are unlike carbonate/limestone islands that are flat and lack significant topography. St. John has steep slopes and the type of rocks immediately near the coast that are prone to weathering. This makes such islands vulnerable to land-based sediment erosion. A multibeam bathymetric survey was conducted in August 2017 in several offshore bays. Because Hurricane Irma passed over the Virgin Islands after the hurricane, there is a valuable opportunity to understand the impact of the hurricane in this offshore environment. This project will complete a second multibeam bathymetric survey and collect sediment cores to assess the extent of the erosion of the island, the quantity of sediments that flowed into the bays, and how the shape of the floor of the offshore bays changed. Understanding these impacts are important for creating more resilient coastal communities. Two graduate students will be involved in the field work and data analysis. The results will be provided to local geoscience and environmental groups.The major scientific objective of this project is to quantify the volume, distribution, and type ofsediment influx that occurred as a result of Hurricane Irma on St. John, U.S. Virgin Islands. Isolating theeffects of this hurricane event will yield a better scientific understanding of how to interpret paleo-storm deposits observed in sediment cores A post-hurricane Irma multibeam bathymetry and backscatter survey is planned to exactly overlap the regions of St. John mapped pre-Irma (Coral Harbor, Johnson Bay, and Saunders Bay) and also, to fill in data gaps from previous surveys. A transect of cores from the interior of Coral Harbor moving seaward will be taken from the survey vessel using a pocket vibra core system. Results of the project will constrain the sediment flux delivered to the marine environment by storms versus non-storm sedimentation. In addition to understanding the hurricane event, these new data together will yield important insights into the relative contribution of a one-off storm event versus that of annual-to-decadal non-storm sedimentation.

圣约翰，维尔京群岛是一个热带岛屿，主要由火山喷发的灰烬和碎屑组成。它暴露于飓风和海啸等主要的地灾。近岸海岸的测深对这些事件的奔跑和激增的严重性影响。圣约翰和其他类似的火山岛不同于碳酸盐/石灰石岛，这些岛屿扁平且缺乏地形。圣约翰有陡峭的山坡和靠近海岸附近的岩石类型，容易出现风化。这使得这样的岛屿容易受到陆基沉积物的侵蚀。 2017年8月在几个海上海湾进行了多片测深调查。 由于飓风在飓风之后越过了维尔京群岛，因此有宝贵的机会了解飓风在这种海上环境中的影响。该项目将完成第二次多束测深调查，并收集沉积物核心，以评估岛屿的侵蚀程度，流入海湾的沉积物的数量以及离岸湾地板的形状如何变化。了解这些影响对于建立更多有韧性的沿海社区很重要。两名研究生将参与现场工作和数据分析。 结果将提供给当地的地球科学和环境群体。该项目的主要科学目标是量化由于飓风Irma在美国维尔京群岛的圣约翰飓风所致的数量，分布和类型的涌入。隔离这项飓风事件的效果将对如何解释在沉积物核心观察到的古疾病沉积物的科学理解，计划对圣约翰映射到圣约翰映射的伊尔马（Coral Harbour，Johnson Bay，Johnson Bay和Saunders Bay）和以前的DADAD GAPS的SUREFES SUREVES fill fill fill fill Data Data Data Glape gaps fill of Data Data Goops cops of St. John映射到圣约翰的区域（St. John映射到圣约翰的区域）。从珊瑚港内部向海内部的岩心的横除将使用袖珍Vibra核心系统从调查容器中占据。该项目的结果将限制通过暴风雨与非风暴沉积物传递给海洋环境的沉积物通量。除了了解飓风事件外，这些新数据还将产生重要的见解，对一次性风暴事件的相对贡献与年度至少年的沉积物的相对贡献。

项目成果

Widespread Deposition in a Coastal Bay Following Three Major 2017 Hurricanes (Irma, Jose, and Maria)

• DOI: 10.1038/s41598-019-43062-4
• 发表时间: 2019-05-08
• 期刊: SCIENTIFIC REPORTS
• 影响因子: 4.6
• 作者: Browning, Trevor N.;Sawyer, Derek E.;Canals-Silander, Miguel
• 通讯作者: Canals-Silander, Miguel