Timing of the Younger Dryas event in East Africa from lake-level changes

摘要: THE last deglaciation was interrupted by an abrupt cooling event, the Younger Dryas, at 11,000& ndash;10,000 yr BP (uncalibrated radiocarbon timescale)1. Originally recognized in climate records from northwest Europe, Dryas has now been identified marine and ice-core worldwide2–6. In tropics, a broadly contemporaneous change is recorded decreases water levels increased salinity of lakes7–9,14, indicating period arid caused reduction ocean-to-land moisture flux. The exact timing these changes relation to event high-latitude remained unclear, however. Here we present based on analyses diatom assemblages, geochemistry magnetic mineralogy radiocarbon-dated sequences laminated lake sediments Lake Magadi East African rift. These provide detailed record lowland equatorial Africa throughout (12,800& 14C BP). We find that lake-level humidity maxima coincide with most rapid phases ice melting Northern Hemisphere, changes, including were synchronous low high latitudes. Thus, effects appear be felt both latitudes without significant time lag.