Reconstruction of the Holocene water-level history for Little Molas Lake, Southern Colorado
presentationposted on 13.10.2014, 00:00 by Jacob E. Buettner
Water is a vital resource and its abundance is affected by climate change. Severe drought brought on by climate change affects water availability in the western U.S. Recent studies suggest El Nino-Southern Oscillation (ENSO) as a possible driver for latitudinal shifts in western storm tracks producing a north-south precipitation dipole anomaly in the western U.S. Here, we generate a lake-level record for Little Molas Lake (LML) in Southern Colorado using various lakebed sediment analyses. To evaluate this anti-phased behavior we will examine lakes in a north-south transect, where LML will provide the southern extent of the transect and Lake of the Woods (LOW), WY, will provide the northern extent of the transect. Accelerated Mass Spectroscopy radiocarbon dating, grain size, and loss-on-ignition analyses were conducted on a near-shore core from LML to establish age constraints on sandy intervals and percent organic content, respectively. LML data was compared with the existing LOW lake-level reconstruction to determine moisture availability trends during the Holocene. Evidence for the N-S precipitation dipole anomaly was observed at 5.5 ka. Ocean core data suggests ENSO frequencies began to increase after 6.0 ka, possibly contributing to the initial anti-phased relationship between water-levels 5.5 ka. Analyzing Holocene water-level responses to climate change may provide suggestions for water resource managers.