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Select Bibliography:

Reheis, M.C., Hershler, R., and Miller, D.M., eds., 2008, Late Cenozoic drainage history of the southwestern Great Basin and lower Colorado River region: Geologic and biotic perspectives: Geological Society of America Special Paper 439, 432 p.

Pigati, J.S., Miller, D.M., Bright, J., Mahan, S.A., Nekola, J.C., and Paces, J.B. 2011. Chronology, sedimentology, and microfauna of ground-water discharge deposits in the central Mojave Desert, Valley Wells, California. Geological Survey of America Bulletin, v. 123, no. 11-12, p. 2224-2239.

Pigati, J.S., Bright, J., Shanahan, T.M., and Mahan, S.A., 2009, Late Pleistocene paleohydrology near the boundary of the Sonoran and Chihuahuan Deserts, southeastern Arizona, USA. Quaternary Science Reviews, 28, 286-300.

Reheis, J.C., Bright, Jordon, Lund, S.P., Miller, D.M., Skipp, Gary, and Fleck, R.J., in review, A half-million-year record of paleoclimate from the Lake Manix core, Mojave Desert, California: submitted to Palaeoclimatology, Palaeogeograph, Palaeoecology.

Paleoclimate Variability of the American Southwest

Coring site on transition from wetland to playa,
adjacent to Zzyzx research station.

The primary objective of this project is to determine how climate conditions in general, and precipitation in particular, have changed over time in the American Southwest. Landscapes and ecosystems in the American Southwest are sensitive to climate change and respond through variations in runoff, lake size, depth to groundwater, and eolian sand/dust movement. Annual and interannual precipitation varies geographically and temporally due to the influences of the El Nino-Southern Oscillation system and occasional intense ”Pineapple Express” storms. We study lake, ground-water discharge, and eolian deposits and packrat middens as archives of environmental change in low- to mid-altitude desert basins to provide better definition of climate variability in this region. We also use several physical and chemical proxy methods to quantitatively reconstruct temperature and precipitation conditions at various sites during the late Quaternary. Current focus is on basins in the Mojave and Sonoran deserts.

Why is this research important?

Predicting precipitation, its potential range of variability, and effects on landscapes and biota is difficult. More precise and accurate records of paleoenvironmental conditions in the Desert Southwest during Pleistocene pluvial periods, wet-dry transitions, and extreme droughts during the Holocene, and correlation of these records with those from nearby marine cores, will constrain the range of expectable natural climate variability and its effects on landscapes and biota, and provide input to land-management agencies, water resource managers, and other groups to help plan mitigation strategies in response to a changing global climate.

Principal Investigator: Marith C. Reheis

Project Team: Jeffrey Pigati, Shannon Mahan, Jeffrey Honke, James Paces Jim Budahn, Dave Miller, Eric Fisher, Paco Van Sistine , Elmira Wan, Dave Wahl, Andrew Cohen, Jordon Bright, Kathleen Springer, David Rhode, Franco Biondi, Scotty Strachan