Authors: Scott Mensing*, University of Nevada - Reno, Wei Wang, Holhut University, Holhut, China, Dave Rhode, Desert Research Institute, Reno, Nevada, Douglas Kennett, University of California, Santa Barbara, CA
Topics: Paleoenvironmental Change, Biogeography
Keywords: Paleoecology, drought, Holocene, pollen, Great Basin
Session Type: Virtual Paper
Start / End Time: 8:00 AM / 9:15 AM
Room: Virtual 40
Presentation File: No File Uploaded
The Late Holocene Dry Period (LHDP) is a hypothesized multi-century long period of below average precipitation that has been previously identified across much of the Great Basin and parts of California. We hypothesize that the pattern of this prolonged dry period follows a north/south dipole comparable to modelled La Niña conditions, with a dry southwest and wet northwest. To test this, we present pollen data from three wet meadow sites along a south to north gradient in central Nevada, located at approximately 39º, 40º and 40.5 º N latitude. Initial results indicate that the site at 39 º N latitude shows a distinct dry LHDP signal, however no pronounced dry signal is present at 40.5 º N latitude, suggesting that if the jet stream persisted along a latitudinal trajectory for some period, it appears to have been about the latitude of the Humboldt River drainage. Sites south of that are predicted to show some evidence for prolonged drought coeval with the LHDP, but sites north of this would not. At present, our chronologies are not sufficiently robust to determine a beginning and ending to the LHDP, although this is part of our ongoing research.