The late Holocene, high-resolution storm and climate archive of the Blue Hole, Lighthouse Reef, Belize (Central America)

在该项目的第二阶段(2年)，从伯利兹蓝洞底部打捞到一个连续的30米长的沉积岩芯，随后对其进行了高分辨率的沉积学、古生物学和地质年代学研究。岩心包括大约12.5ka，即完整的全新世，进入最新的冰川后更新世(年轻的仙女座)。沉积序列自上而下可划分为三个单元，包括：(1)事件层发育的多变海相单元(&lt；5.7ka BP)；(2)局限海-微咸水单元(5.7-7.2ka BP)；(3)富有机质湖相单元(7.2-12.5ka BP)。总共确定了694个事件(气旋)层，用于编制独特的、超长的、每年分解的西大西洋风暴档案。记录表明，除全新世气候最佳期(6.8-5.9ka BP)的两个短时段外，12-3.5ka BP的风暴活动相对较低，而3.5ka以来的风暴活动较高，在中世纪暖期(MWP)和近代工业变暖(IW)期间有两次高峰。根据与历史风暴记录的比较，可以定量地将风暴床厚度和纹理与报告的最大值联系起来。风速，即根据风暴强度校准事件层的沉积学特征。鉴于取回的岩芯出乎意料的巨大长度和这一记录的独特性，我们要求为该项目提供最后一年的资金，以便按年度分辨率进行地球化学分析(d18O、d13C、TEX86)。最后一个资助期的目标包括：(1)将每年解析的SST记录扩展到较年轻的仙女木；(2)开发等长的d13C记录。目标1将允许汇编一份特殊的全新世SST记录，这将使人们能够根据全新世气候变化，包括大西洋年代际涛动的影响，全面解释新的风暴记录。根据目标2，可以破译气候变化的表现，如气旋频率、降水和土壤侵蚀，这反过来又能够评估中美洲的水文气候变化如何作为过去约3ka期间区域文化发展和玛雅高等文化最终崩溃的催化剂。

In the second phase of the proj2ect (2 years), a continuous, 30 m long sediment core was retrieved from the bottom of the Belize Blue Hole, which was subsequently investigated at high resolution with regard to sedimentology, paleontology, and geochronology. The core encompasses some 12.5 ka, i.e., the complete Holocene into the latest, postglacial Pleistocene (Younger Dryas). The sedimentological succession may be subdivided in three units from top to base including (1) a varved marine unit with well-developed event beds (<5.7 ka BP), (2) a restricted marine to brackish unit (5.7-7.2 ka BP), and (3) an organic-rich lacustrine unit (7.2-12.5 ka BP). In total, 694 event (cylone) layers were identified that were used to prepare a unique, exceptionally long, annually resolved storm archive of the western Atlantic. The record indicates that storm activity was relatively low from 12-3.5 ka BP, with the exception of two short intervals during the Holocene Climate Optimum (6.8-5.9 ka BP), and high since 3.5 ka, with two maxima during the Medieval Warm Period (MWP) and the recent time of Industrial Warming (IW). Based on comparisons with historical storm records, it was possible to quantitatively relate storm bed thickness and texture to reported max. wind speed, i.e., to calibrate sedimentological characteristics of event beds based on storm intensity. Given the unexpected, great length of the retrieved core and the uniqueness of this record, we ask for a final year of funding for the project in order to conduct geochemical analyses (d18O, d13C, TEX86) at annual resolution. The objectives of the final funding period include (1) the extension of the annually resolved SST-record to the Younger Dryas and (2) the development of a d13C-record of equal length. Objective 1 will allow to assemble an exceptional Holocene SST-record, which will enable a comprehensive interpretation of the new storm record in the light of Holocene climate variability, including the influence of the Atlantic Multidecadal Oscillation (AMO). Based on objective 2, manifestations of climate variability such as cyclone frequency, precipitation, and soil-erosion may be deciphered, which in turn enable an evaluation as to how Mesoamerican hydro-climate changes operated as a catalyst for the regional cultural development and eventual collapse of the Maya high culture during the past ca. 3 ka.