G03_P02

Bulk Organic Carbon Isotopes From the Santa Clara River During Rain Events

Thomas K¹, Hauksson N¹, Druffel E¹

¹UC Irvine, Irvine, United States

Small mountainous rivers leading into the ocean, such as the Santa Clara River in Southern California, export considerable amounts of organic carbon to the ocean, and the magnitude and composition of which reaches the ocean is widely studied. With rainfall events in California mostly during winter, the composition and ¹⁴C age of the organic carbon deposited by rivers is likely dependent on the magnitude of these events. In this study, we measured Δ¹⁴C and δ¹³C values of sedimentary organic carbon (SOC) and particulate organic carbon (POC) after rain events near the Santa Clara River. We present these analyses that show high variability of ¹⁴C age and composition of organic material moved downstream with the amount of precipitation and runoff entering the river. This study contributes to our knowledge of organic carbon cycling from small mountainous rivers.