The Fredy & Nadine Herrmann Institute of Earth Sciences, The Hebrew University of Jerusalem, The Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel.
Interuniversity Institute for Marine Sciences, Eilat, 88103, Israel.
Nat Commun. 2019 Aug 23;10(1):3803. doi: 10.1038/s41467-019-11701-z.
Northern and eastern Africa were exposed to significantly wetter conditions relative to present during the early Holocene period known as the African Humid Period (AHP), although the latitudinal extent of the northward expansion of the tropical rain belt remains poorly constrained. New records of Th-normalized accumulation rates in marine sediment cores from the Red Sea and Gulf of Aden are combined with existing records of western Africa dust and terrestrial records across the Sahara Desert, revealing that fluxes of dust transported east from the Sahara decreased by at least 50% during the AHP, due to the development of wetter conditions as far north as ~22°N. These results provide the first quantitative record of sediment and dust accumulation rates in the Red Sea and the Gulf of Aden over the past 20 kyrs and challenge the paradigm of vast vegetative cover across the north and northeastern Sahara Desert during the AHP.
北非和东非在全新世早期（即非洲湿润期，AHP）的气候条件比现在更加湿润，尽管热带雨带向北扩展的纬度范围仍受到很大限制。红海和亚丁湾海洋沉积物岩芯中 Th 归一化积累率的新记录与西非尘埃的现有记录以及撒哈拉沙漠的陆地记录相结合，表明撒哈拉沙漠东部向东输送的尘埃通量在 AHP 期间至少减少了 50%，这是由于最北至~22°N 的条件变得更加湿润。这些结果提供了过去 20 千年来红海和亚丁湾沉积物和尘埃积累率的首个定量记录，挑战了 AHP 期间北非和东北撒哈拉沙漠地区存在大面积植被覆盖的范式。
