RUI: P2C2--Reconstruction of Recent and Late Holocene Tropical Cyclone Landfalls in Northwestern Australia using Flood Deposits in Aragonite Stalagmites

该奖项有助于从热带西澳大利亚金伯利地区的洞穴沉积物中建立热带气旋活动的记录，并可追溯到全新世晚期（约4,000年B. P.）。研究人员先前的研究表明，文石石笋在金伯利的洞穴中非常丰富，从全新世晚期到现在，其特征是极高的生长速度，洞穴中的粘土只在热带气旋引发的洪水中沉积在石笋表面。由于这些石笋含有较高的铀丰度、高的δ 234-铀值，并且基本上没有碎屑（洪水沉积物除外），因此可以使用铀钍质谱法以极高的精度（上个世纪±1年）测定它们的年代。为了限制淹没洞穴所需的气旋距离/强度阈值，研究人员将联合收割机结合石笋沉积洪水记录与稳定同位素分析，在过去100年的增长;一个时间间隔，其中热带气旋强度和风暴路径的历史记录。这一分析将有助于建立一个基线，用于估算记录在单个洞穴粘土层中的过去风暴的强度-距离比。更广泛的影响包括更好地了解气旋活动的历史和开发新的气候代用指标的潜力。 该研究还涉及实质性的本科生参与该项目。

This award helps develop a record of tropical cyclone activity from speleothems recovered from the Kimberley region of tropical Western Australia and dated to the late Holocene (~4,000 yr B.P.).Previous research by the researcher demonstrated that aragonite stalagmites are abundant in caves in the Kimberley through the late Holocene and up to the present time, are characterized by extremely high growth rates, and the caves trap clays deposited on stalagmite surfaces only during tropical cyclone-induced flooding. Because these stalagmites contain elevated Uranium abundances, high delta 234-Uranium values, and are largely devoid of detritus (other than in flood deposits), they can be dated with extremely high precision using Uranium-Thorium mass spectrometry (±1 year within the last century). In order to constrain the cyclone distance/intensity threshold required to flood the caves, the researcher will combine the stalagmite sedimentological flood records with stable isotopic analyses over the last 100 years of growth; an interval for which historical records of tropical cyclone intensity and storm track are available. This analysis will help establish a baseline for estimating the intensity-distance ratio of past storms recorded as clay layers in individual caves.The broader impacts involve the potential for greater understanding of the history of cyclonic activity and the developement of a new climate proxy. The research also involves substantive undergraduate student participation in the project.