The geologic record of Hurricane Irma in a Southwest Florida back-barrier lagoon

Data was gathered from four cores taken in a back-barrier lagoon on Big Hickory Island, Florida, USA. Hurricane Irma occurred in September 2017 and these cores were taken in June 2018. Sedimentary analyses (grain size, % moisture, % inorganic material) were conducted on three of the cores whereas the fourth was used for 210Pb dating. These cores were also studied for foraminifera species. Sedimentary analyses showed a tempestite in the core top (ranging from 0-9.5 cm), which was supported by larger grain size, low moisture content, and high inorganic content. Several marine species were present in the tempestite layer of each core, but no foraminifera were present in the lagoonal sediments below that tempestite. A Constant Rate of Supply (CRS) model was coupled with 210Pb data to demonstrate sedimentation rates during Hurricane Irma and create a core chronology.本数据集的数据采集自美国佛罗里达州大希科里岛（Big Hickory Island）一处障壁后泻湖（back-barrier lagoon）获取的4根沉积物岩芯。飓风厄玛（Hurricane Irma）于2017年9月过境，本次岩芯采样工作于2018年6月完成。研究人员对其中3根岩芯开展了沉积学分析，包括粒度测试、含水率测定及无机质占比分析，剩余1根岩芯则用于210Pb测年（210Pb dating）。同时，所有岩芯均开展了有孔虫（foraminifera）物种鉴定研究。沉积学分析表明，每根岩芯的顶部0~9.5 cm层位均存在风暴沉积层（tempestite），该层粒度偏粗、含水率较低且无机质含量较高，佐证了该风暴沉积的发育。每根岩芯的风暴沉积层中均检出多种海洋物种，但风暴沉积层下方的泻湖沉积物中未发现有孔虫。研究采用恒定供给速率（Constant Rate of Supply, CRS）模型结合210Pb测年数据，重建了飓风厄玛影响时期的沉积速率，并建立了岩芯的年代序列。