US-Israel Dissertation Enhancement: Holocene Paleoclimate Investigations in the Venezuelan Andes Using Oxygen Isotopes in Ditom Opal

University Of Massachusetts Amherst, Amherst MA

Investigators

Abstract

0004425 Bradley This dissertation enhancement award supports a U.S. graduate student, Pratigya J. Polissar, working under the guidance of Raymond S. Bradley, Department of Geosciences, University of Massachusetts, who will spend six months in the laboratory of Aldo Shemesh at The Weizmann Institute of Science in Rehovot, Israel. The research will focus on the technique for measuring the oxygen isotope composition of diatom silica and applying it to Holocene lake sediments from Venezuela. The analysis of isotopes in diatom silica is difficult and Dr. Shemesh's lab is one of the best sites in the world for these measurements. Understanding the natural variability of the climate system is essential for prediction and interpretation of current and future climate change. In tropical regions, the balance between precipitation and evaporation is a key climatic parameter and analysis of the oxygen isotopic composition of diatoms preserved in lake sediments is a relatively new and exciting method for reconstructing it. This research will make an important contribution to our understanding of climate by providing a detailed paleoclimate record of changes in tropical South America during the last 10,000 years.