Late Pleistocene changes in winter moisture source in the coastal southwest United States ...

• Main Author: Wu, Mong Sin author
• Format: Thesis
• Language: English
• Published: University of Southern California Digital Library (USC.DL) 2014
• Subjects: Geological Sciences degree program; Master of Science degree; College of Letters, Arts and Sciences school; Pacific; North Atlantic
• Online Access: https://dx.doi.org/10.25549/usctheses-c3-517796; https://digitallibrary.usc.edu/asset-management/2A3BF1LPJSOB

During the Late Pleistocene, millennial-scale abrupt transitions in the North Atlantic may have influenced climate in remote regions including the western United States (US). Several speleothem reconstructions from the Great Basin and interior southwest US capture oxygen isotopic evidence for shifts in Pacific and North American Monsoon derived storm tracks, revealing the power of isotopes in precipitation to track hydroclimatic regime change. Here, we present a high-resolution lake sediment leaf wax hydrogen isotope record spanning 9 ? 32 cal. kyr BP from Lake Elsinore, California, in the coastal southwest US. This site provides a valuable archive within an exclusively Pacific-influenced precipitation zone. We use leaf wax hydrogen isotopic composition (?Dwax) as a proxy for ?D of precipitation (?Dprecip), a tracer of moisture sources and storm trajectories. Our interpretation is further based on grain size and graminoid pollen data from the same core, as well as time-transient experiments performed with ...