Department Chair, and Professor
- Ph.D., University of Minnesota, 1997
- B.A., Pomona College, 1989
- GEOL 240 - Historical Geology
- GEOL 300 - Earth Systems and Global Change
- GEOL 445 - Paleoclimatology
- GEOL 465 - Physical and Chemical Oceanography
- GEOL 510 - Biogeochemical Cycles
- ESP 400 - Environmental Science and Policy Capstone Project
- Isotope Geochemistry
My research involves the reconstruction of past climatic change using geochemical signatures archived in lake sediments. I focus on the oxygen-isotopic composition of endogenic carbonates as a proxy for hydrologic variability, although I utilize a suite of proxies that include biogenic silica concentrations, grain-size variations, C/N ratios, and mineralogy. More recently, I have begun to employ compound-specific isotopes of leaf waxes to sites lacking carbonates. I study the evolution and variability of a variety of climatic phenomena including ENSO, the Pacific Decadal Oscillation, the Southeast Asian monsoon, seasonal changes in atmospheric precipitation in the Mediterranean region, and drought. I specialize in high-frequency (sub-decadal) records derived from annually laminated sediments.
I have also started work on biomarkers, specifically coprostanol, as indicators of human presence on the landscape. My goal is to reconstruct relative changes in human population with simultaneous.
- western Iran and the interactions of early civilizations with climate change
- drivers of variations in the monsoon climate of Vietnam
- understanding and refining the use of coprostanol as an indicator of past human population change