Adrian Tasistro-Hart, 2017, Geosciences

My summer research, which will form the foundation for my junior papers and senior thesis, centered on detecting long term (10,000-100,000 year) climate cyclicity in a late Cretaceous (65 million-year-old) lake in western Bolivia. These cycles, the same that paced the ice ages of the past several million years, are caused by periodic wobbles in Earth’s rotation and orbit around the sun. Because the late Cretaceous was marked by atmospheric carbon dioxide concentrations more than double those of today, this lake could demonstrate if and how these astronomical cycles influence global climate in a “hot-house” world. To detect these cycles, I led a two-month field season in the Bolivian Andes, measuring the thicknesses of rock layers that had been deposited in the lake and collecting samples from those layers. With measurements such as magnetic susceptibility and mineralogy taken from the samples, in addition to high-resolution aerial imagery collected with a drone, I will attempt to detect periodic signals in the sedimentary record that I can then correlate with astronomical cycles. By planning and executing my own field season, I learned how to manage the logistics of international research, to prioritize research objectives in a limited amount of time, and to adapt to challenges.