4,500 years of Hydrologic Variability from Zaca Lake, close to the Santa Barbara Basin

University Of Southern California, Los Angeles CA

Investigators

Abstract

Funding is provided to develop a high-resolution (decadal or better), multi-proxy climate record spanning the past 4 millennia from the sediments of Zaca Lake, Santa Barbara County, California. The researchers use a suite of approaches including molecular isotopic analyses (i.e. D/H ratios in aquatic and terrestrial biomarkers), biological analyses (including charcoal counts), and physical sediment analyses (including grain size). The goals are to reconstruct the nature and frequency of climate variability (droughts and pluvials), flood event stratigraphy and changes in precipitation and catchment hydrology under changing climate. Correlation of the Zaca Lake record to regional and global climate records and forcings are used to explore the mechanisms driving these changes. In particular, the proximity of Zaca Lake to the Santa Barbara Basin enables comparison of this new high-resolution terrestrial record to a high-resolution marine record within 50km. The broader impacts include cross-institutional collaboration between University of Southern California and California State University at Fullerton (#5 in the nation for the number of bachelor's degrees awarded to minority students), support for a new female researcher, and the training of two graduate students and multiple undergraduate students at both institutions. Zaca Lake provides a rare opportunity in otherwise lake-poor Southern California to reconstruct the frequency and severity of past floods and droughts beyond the historical period, with findings of relevance to hazard and water management decisions in this water-stressed and highly populous region.