Research

PALEOCEANOGRAPHY, PALEOCLIMATOLOGY, MARINE STRATIGRAPHY

Jim Zachos's research interests encompass a wide variety of problems related to the biological, chemical, and climatic evolution of late Cretaceous and Cenozoic oceans. He measures the chemical composition of shells from marine sediments to reconstruct past changes in ocean temperature & circulation, continental ice-volume, productivity, and carbon cycling. His research is oriented toward identifying the mechanisms responsible for driving long and short-term changes in global climate.

Zachos, his students and colleagues are currently engaged in research projects oriented toward resolving the nature of rapid and extreme climate transitions in earths past. These projects involve the application of isotope and trace metal ratios of sediments to reconstruct ocean temperature and chemistry for climatic events such as the Paleocene-Eocene Thermal Maximum (~56 mya), the middle- and early Eocene Climatic Optimum, the Eocene-Oligocene Transition. They are also investigating ocean acidification (see acid oceans) that accompanied the extreme transient warmings. This includes a new project focused on coastal oceans.

Zachos is a fellow of the American Geophysical Union, Geological Society of America, California Academy of Sciences, American Academy of Arts and Sciences, and a member of the National Academy of Sciences (2017). He is also a recipient of the European Geosciences Union 2016 Milankovic Medal.