Holocene and Glacial Climate Change in the Desert Southwest, USA: New Isotopic Records from Speleothems

University Of Arizona, Tucson AZ

Investigators

Abstract

Climatic extremes in the desert southwest of North America control the availability of water and the sustainability of many human and natural systems. Instrumental records demonstrate significant variability of climate in the past century, particularly related to the El Nino-Southern Oscillation (ENSO) system. Longer records from tree-ring reconstructions reveal the recurrence of significant prolonged (decadal to multidecadal) droughts in recent centuries. Continuous high-resolution records of desert southwest climate on Holocene and glacial time scales are lacking. This award will fund a research program to develop a promising archive of climate information in this region, the records preserved in speleothems (cave deposits). This work will generate the first highly resolved, well-dated, calibrated, replicated records of Holocene and glacial climate in the desert southwest. This work will include expanded speleothem sampling, modern cave monitoring for calibration, improvement of U/Th dating methodologies, and the development and interpretation of new, replicated high-resolution climate records for the Holocene. This work should make important contributions to the reconstructed climatic records of the US desert southwest. Outreach components include the involvement of local cavers, K-12 education, and US Forest Service collaboration.