Tropical cyclone wind speed constraints from resultant storm surge deposition: A 2500 year reconstruction of hurricane activity from St. Marks, FL
Tropical cyclone wind speed constraints from resultant storm surge deposition: A 2500 year reconstruction of hurricane activity from St. Marks, FL
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DOI：
10.1002/ggge.20217
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发表时间：
2013-08-01
影响因子：
3.5
通讯作者：
Donnelly, Jeffrey P.
中科院分区：
文献类型：
--
作者：
Brandon, Christine M.;Woodruff, Jonathan D.;Donnelly, Jeffrey P.
最近的研究表明，过去几千年来强烈（萨菲尔-辛普森飓风等级中的3级）飓风袭击的模式可能与这一时期飓风活动的总体模式不同。以前的研究通常依赖于指定一个阈值风暴强度所需的沉积物超洗信号在一个特定的沿海网站的基础上的历史类似物。在这里，我们改进了这种方法，提出了一种新的逆模型技术，限制最有可能的风速所需的最大粒径内产生的风暴存款。作为一个案例研究，该技术被应用到事件层中观察到的沉积物从西北佛罗里达沿海天坑。我们发现：（1）现代沉积物的模拟风速与影响该地点的历史飓风强度一致，（2）在大约2500年的记录中，所有沉积物都能够由飓风产生，以及（3）在大约1700年至大约600年B. P.之间，观察到强烈飓风频率增加的时期，从B. P.到现在，从大约2500年到大约1700年和大约600年观测到风暴频率。这与附近遗址的先前重建一致。强烈飓风袭击频率的变化可能与墨西哥湾环流的渗透程度有关。
Recent work suggests that the patterns of intense (category 3 on the Saffir-Simpson scale) hurricane strikes over the last few millennia might differ from that of overall hurricane activity during this period. Prior studies typically rely on assigning a threshold storm intensity required to produce a sedimentological overwash signal at a particular coastal site based on historical analogs. Here, we improve on this approach by presenting a new inverse-model technique that constrains the most likely wind speeds required to transport the maximum grain size within resultant storm deposits. As a case study, the technique is applied to event layers observed in sediments collected from a coastal sinkhole in northwestern Florida. We find that (1) simulated wind speeds for modern deposits are consistent with the intensities for historical hurricanes affecting the site, (2) all deposits throughout the approximate to 2500 year record are capable of being produced by hurricanes, and (3) a period of increased intense hurricane frequency is observed between approximate to 1700 and approximate to 600 years B.P. and decreased intense storm frequency is observed from approximate to 2500 to approximate to 1700 and approximate to 600 years B.P. to the present. This is consistent with prior reconstructions from nearby sites. Changes in the frequency of intense hurricane strikes may be related to the degree of penetration of the Loop Current in the Gulf of Mexico.