Collaborative Research: High-Resolution, Low-Latitude Paleoclimatology Through Scientific Drilling of Lake Bosumtwi, Ghana

该合同将增加国际大陆钻探计划（ICDP） 120万美元的运营资金，从Bosumtwi湖（位于西非加纳热带森林低地的一个陨石撞击坑）获取多个湖泊岩心，用于古气候分析。研究人员的目标是建立一个多代理和年际到千年尺度的过去~ 100万年（Ma）的气候变化记录。将对从这些岩心获得的数据进行检查，以确定北大西洋、非洲和亚洲地区气候之间的潜在联系。该湖位于热带辐合带（ITCZ）的季节性通道下方，在水文上与深缺氧水域封闭，保留了每年的分层。该团队之前的研究已经获得了记录陨石坑撞击起源的地震剖面，而对先前回收的活塞沉积物岩心的分析产生了800年的环境数据记录。这些岩心表明，在新仙女木期和海因里希1期和海因里希2期气候事件期间，非洲夏季风的强度有所减弱。新的地点将钻探多个温暖的间冰期，并将进一步加深古气候界对热带气候变化的更广泛理解。这项研究将在与加纳科学家的充分合作下进行，以支持美国科学家和他们的加纳同事之间的能力建设和技术转让。研究基金还将支持美国研究生，并为他们提供独特的研究经验。

This award is to augment $1.2M in operational funds from the International Continental Drilling Program (ICDP) to obtain multiple lake cores for paleoclimatic analyses from Lake Bosumtwi, a meteorite impact crater located in the tropical forest lowlands of Ghana, West Africa. The researchers aim to produce a multi-proxy and inter-annual to millennial scale record of climate change over the last ~1.0 million years (Ma). The data derived from the cores will be examined for potential linkages among climate from the North Atlantic, Africa, and the Asia regions. The lake is located beneath the seasonal passage of the Inter Tropical Convergence Zone (ITCZ) and is hydrologically closed with deep anoxic waters that preserve annual laminations. Previous research by the team has yielded seismic profiles that documented the impact origin of the crater while analyses of previously recovered piston sediment cores produced an 800-year record of environmental data. These cores have shown that the intensity of the African summer monsoon decreased during the Younger Dryas and during Heinrich 1 and 2 climatic events. The new sites will drill through multiple warm interglacial periods and will further the paleoclimate community's broader understand of climate variability from the Tropics. This research will be carried out in full collaboration with Ghanaian scientists to support capacity building and technology transfer between the US scientists and their Ghanaian colleagues. The research funds will also support American graduate students and provide them with a unique research experience.