Late Quaternary climate in the southern foothills of the Brooks Range, Alaska based on stable isotope analysis of lake sediment

• Main Author: Wilber, Adrienne Kathleen
• Format: Text
• Language: unknown
• Published: Carleton Digital Commons 2011
• Subjects: stable isotope; Brooks Range; paleolimnology; Chironomidae; Younger Dryas; Arctic; Selby; Climate change; Alaska
• Online Access: https://digitalcommons.carleton.edu/comps/764

Modern climate change is accelerated in the arctic. Moisture has played an integral role in shaping the arctic landscape and ecosystems during periods of warming. Paleoclimate studies on terrestrial materials help compare current climate shifts to those that occurred in the past and predict the effects of future warming. Lake sediments provide an archive of past climate trends. Chironomid larvae living in lake water record the isotopic signature of the water in their chitin. This record can be used as a proxy for the isotopic composition of paleo-precipitation. I present an oxygen stable isotope record and carbon to nitrogen ratio for a radiocarbon dated sediment core from Lake Selby in the Brooks Range, Alaska. Lake water chemistry indicates that the oxygen stable isotope record from Lake Selby reliably records isotopic shifts in precipitation from 14,000 cal BP to present. My results show either a warming trend at the Pleistocene / Holocene transition or a Younger Dryas cooling signal, and increased winter precipitation in the early half of the Holocene. Terrestrial climate shifts in the arctic are often regional in effect. This paper can a provide a historic context for current climate change in the foothills of the Brooks range, and contribute to future research by providing additional data to contextualize paleoenvironmental studies in the area.