Research in USC's Department of Earth Sciences includes efforts to understand the dynamics of the global carbon cycle, and its relation to climate, life, and other (bio)geochemical cycles.
Research in Ocean Sciences (facilitated in part through the dedicated Ocean Sciences Graduate Program) is a particular strength at the university, and the carbon cycle is interwoven among the work of all Ocean Sciences faculty at USC. Studies in the modern ocean system are providing insights into life in the upper ocean and deep ocean sediments with key implications for nutrient cycles, CO2 cycling, climate, and life on this and other planets. These studies include:
- Various groups examining the production of organic carbon in the upper ocean, the first step in the "biological pump" that helps sequester atmospheric CO2. These studies involve biological rate measurements, geochemical measurements and models, and various "process-related" measurements intended to ascertain what controls ocean production (Berelson, Hammond, Sanudo-Wilhelmy).
- Work to measure the flux of organic carbon in the form of settling particles, studied with sediment traps and by inference through models of ocean chemistry (Berelson, Hammond). Both organic carbon and inorganic carbon (CaCO3) fall to the sea floor and become part of the sedimentary package that eventually turns into a sedimentary rock.
- Studies of diagenesis (Berelson, Hammond, West), examining changes that occur to carbon-bearing materials post deposition, and determining the reactions that must be taken into account by any interpretation of environmental conditions based on a study of the rock record. Research into carbon cycling in the deep biosphere below the ocean floor, coordinated through the Center for Dark Energy Biosphere Investigations (Edwards).
Work in the department also investigates the global transfer of carbon from the land surface to the oceans, exploring controls on both the flux of organic carbon transported by rivers and the rates of chemical weathering reactions (West). Tied to research on chemical weathering is work on the accelerating weathering reactions, as a technology for reduction of atmospheric CO2.