kayla-hollister

Long-term continuous sea surface temperature record of Tropical Atlantic across the Cenozoic era

Abstract

There are large gaps in our understanding of eastern African hydroclimate during the Mid- Pleistocene Transition (MPT), and what is potentially driving this climate variability, due to a lack of long, continuous records. The MPT is a particularly interesting time in Earth’s history, showing a change in glacial-interglacial variability from mostly symmetrical cycles, with a period of 41,000 years, to asymmetric cycles of 100,000 years. Hominins in eastern Africa are thought to have been influenced by local climate variability, against a backdrop of this interesting global transition, but existing records show conflicting trends in aridity and support different regional climate drivers. I propose to analyze leaf wax hydrogen isotopes and sea surface temperatures (SSTs) from alkenones from IODP Site U1476 from coastal southeastern Africa to test the hypotheses that SSTs are similar to those further south in the Mozambique Channel and not those off northeastern Africa, and that these SSTs, particularly the gradient in SSTs across the Indian Ocean, drove MPT hydroclimate in this region more than high latitude forcing.

Biography

My interest in paleoclimate research began during an undergraduate course on climate change at the University at Buffalo (UB), where I received my B.S. and M.S. in Geological Sciences. This interest led me to a position in the UB Organic and Stable Isotope Biogeochemistry Lab, where I became fascinated by Arctic climate change. My senior thesis involved reconstructing Holocene precipitation seasonality on western Greenland using leaf wax hydrogen isotopes. During my Masters, I immersed myself in understanding leaf wax preservation in lake sediments on southern Baffin Island. Now, as a Ph.D. student at the University of Notre Dame, I am shifting my focus towards paleoclimate reconstructions in deep time. I am excited to use the Schlanger Fellowship to observe the interaction between sea surface temperatures in the Mozambique Channel and east African hydroclimate, particularly during the Mid-Pleistocene Transition.