Doctoral Dissertation Research: A 1,200-Year, High-Resolution Record of Hurricane Activity for Southern New England

目前关于飓风活动自然变化的记录不足以准确预测飓风灾难事件的重现间隔。 对提供飓风活动长期代用记录的沿海沉积序列的研究可用来解决这一问题。 这个博士论文研究项目将主要基于下神秘湖的沉积记录，为波士顿地区开发一个长达1,200年的飓风和热带风暴活动的高分辨率记录。 神秘湖的记录是分层的，似乎保存着上个千年来每年可分辨的沉积档案。 通过物理沉积学和硅藻组合的变化，可以在沉积物中检测到飓风风暴潮和过洗事件。 根据对纹层的显微镜检查和放射性测年法，该项目将为该区域过去一千年的这些事件制作高分辨率记录。 该记录将与从波士顿港沼泽开发的低分辨率记录进行比较。 这第二个记录在其他地方进行的重建过去飓风频率的研究中更为典型。 预计神秘湖记录将保存更多的微妙事件和时间间隔较近的事件，这些事件在较低分辨率的记录中并不明显，该项目将有助于了解天气气候控制如何缓和不同的区域飓风活动模式。 通过研究长期气候变化背景下飓风事件的频率，特别是过去千年“小冰河时代”寒冷时期与温暖时期相比的事件频率，该项目的结果可能表明在温室气体导致气候变暖的情况下预期的飓风活动。 由于人口的增加，越来越多的人居住在受飓风影响的沿着或附近，因此更好地了解飓风活动和复发间隔的价值更大。 目前，美国总人口的一半以上居住在脆弱的沿海地区，预计到2015年，这些人口将再增加20%。 再加上全球变暖如何影响飓风活动的不确定性，城市规划者、灾害管理机构和全球保险业开始怀疑，最近发生的安德鲁飓风等灾害是否只是未来几十年越来越多代价更高、致命性更强的热带风暴的前兆。 这个项目的结果将有助于回答这个问题所需的知识不断增长。 作为博士论文研究改进奖，该奖项还将提供支持，使有前途的学生建立一个强大的独立的研究生涯。

The present record of the natural variability of hurricane activity is insufficient to accurately predict the recurrence intervals for hurricane catastrophe events. The study of coastal sedimentary sequences that provide long-term proxy records of hurricane activity can be used to address this issue. This doctoral dissertation research project will develop a 1,200-year-long high-resolution record of hurricane and tropical storm activity for the Boston area based primarily on the sedimentary record from the Lower Mystic Lake. The Mystic Lake record is laminated and appears to hold an annually resolvable archive of sedimentation for the last millennium. Hurricane storm surge and overwash events can be detected in the sediments by changes in physical sedimentology and diatom assemblages. Based on microscopic examination of the laminae and radiometric dating, this project will develop a high-resolution record of these events for the region over the last millennium. The record will be compared with a lower-resolution record developed from a marsh in Boston Harbor. This second record is more typical of studies carried out elsewhere to reconstruct past hurricane frequency. It is expected that the Mystic Lake record will preserve more subtle events and events that are closely spaced in time, occurrences that are not evident in a lower-resolution record.The project will contribute to understanding of how synoptic climate controls may moderate different regional modes of hurricane activity. By examining the frequency of hurricane events in the context of long-term climate changes, in particular the frequency of events over the past millennium from the cold episodes of the "Little Ice Age" compared to warmer periods, results of the project may suggest the expected hurricane activity in a climate warmed by greenhouse gases. The value of better understanding hurricane activity and recurrence intervals is enhanced by populations that have led increasing numbers of people to live along or near coastlines that are subject to hurricanes. More than half of the total U.S. population currently is located in vulnerable coastal zones, and these populations are expected to swell another 20 percent by 2015. Combined with the uncertainty of how global warming may affect hurricane activity, civic planners, disaster management agencies, and the global insurance industry have begun to wonder whether recent disasters like Hurricane Andrew are simply a precursor to an increasing number of even more costly and deadly tropical storms in the coming decades. Results from this project will contribute to the growing body of knowledge necessary to answer this question. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.