A Spatiotemporal View of the African Humid Period from Leaf Wax Isotopes

Thursday, 18 December 2014: 2:55 PM
Jessica E Tierney, WHOI, Woods Hole, MA, United States and Peter B deMenocal, Lamont-Doherty Earth Obs, Palisades, NY, United States
The timing and abruptness of both the onset and termination of the African Humid Period (AHP) across the Sahara have been a subject of controversy, with some paleoclimate records indicating abrupt transitions, and others, gradual ones. Records of the hydrogen isotopic composition of leaf waxes (dDwax) spanning the AHP have proven to be key players in the debate, as dDwax appears to be a reliable proxy for aridity across semi-arid Africa. We present here four new dDwax chronologies from a latitudinal transect of marine sediment core sites offshore from the Sahara. Synthesizing these data with existing dDwax chronologies, we arrive at a new and detailed spatiotemporal picture of the AHP that reveals spatial patterns in both the timing and abruptness of the AHP termination.