Change at 85 degrees south: Shackleton Glacier region proglacial lakes from 1960 to 2020

Abstract

Abstract Over the last two decades, anomalous warming events have been observed in coastal Antarctic regions. While these events have been documented in the Ross Sea sector, the Antarctic interior is believed to have been buffered from warming. In this work, we present data from lakes located near Mt. Heekin and Thanksgiving Valley (~85° S) along the Shackleton Glacier, which are believed to be the southern-most Antarctic dry valley lakes. In 2018, the lakes were characterized, repeat satellite images were examined, and lake water chemistry was measured. Our analysis shows that lake areas recently increased, and the water-soluble ion chemistry indicates a flushing of salts from periglacial soils, likely from increased glacial melt as illustrated by water isotope data. Our results show that high southern latitude ice-free areas have likely been affected by warm pulses over the past 60 years and these pulses may be quasi-synchronous throughout the Transantarctic Mountains.