Uranium-series dates on Overwash Deposit Corals from Anegada, British Virgin Islands

Uranium-series dates from coral boulders narrow the time window of a medieval tsunami from faulting in the Puerto Rico Trench. Previously reported traces of this sea flood include hundreds of coral boulders that came to rest hundreds of meters inland on Anegada, British Virgin Islands. Many of these retain the form of living coral colonies. U-series dates on coral boulders from Anegada now provide limiting dates for the tsunami. The narrowest limits were obtained from cored interior bands of a boulder that retains a life-like hemispherical form. By those limits, the tsunami dates between 1386 and 1391 C.E. and probably occurred in summer or fall.基于珊瑚砾石的铀系测年（Uranium-series dates），研究人员得以缩小波多黎各海沟断层活动引发的中世纪海啸的时间窗口。此前已有报道称，该海啸引发的海侵痕迹包括英属维尔京群岛阿内加达岛上的数百块珊瑚砾石，这些砾石被搬运至内陆数百米处后沉积，其中多数仍保留了活体珊瑚群体的原始形态。针对阿内加达岛珊瑚砾石开展的铀系测年，现已为该海啸事件提供了年代限定；其中精度最高的限定结果取自一块保留类活体半球形态的砾石的钻取内部条带。据此限定结果，该海啸发生于公元1386至1391年之间，且大概率发生于夏季或秋季。