— November 26, 2018
A three-year project will study how the West Antarctic Ice Sheet responded to climate change during the last interglacial period (approximately 125,000 years ago) by studying the glacial and volcanic history of Mount Waesche in West Antarctica. The team of scientists include Nelia Dunbar (NMBG director), Bill McIntosh (NMBG emeritus), Matt Zimmerer (NMBG field geologist), NMT graduate student Jeremy McComas, as well as collaborators from Harvard and the University of Maine.
Understanding how the West Antarctic Ice Sheet responded to warmer than current temperatures is challenging because most of the evidence for smaller than present ice sheets is now covered by ice. To address this, the team will drill through the ice sheet to recover cores of volcanic rocks from the flanks of Mount Waesche, a volcano in West Antarctica that was active prior to and perhaps after the last interglacial period. By determining the exposure ages of volcanic rocks in the cores, or when the samples were last exposed to solar rays, the team will be able to estimate how much ice was lost during the interglacial period. Results of this project are expected to have significant implications for future changes to the West Antarctic Ice Sheet as a result of current warming trends.
The project involves two field seasons at the very remote Mount Waesche. The first field season, beginning in December 2018, will focus on mapping the southern flank of the volcano to determined which flows are continuous beneath the current ice sheet. To help with this, the team will also conduct a ground penetrating radar survey to identify flows beneath the ice. The first field season will also focus on collecting rocks to determine the eruptive history, specifically targeting flows that erupted just prior to the last interglacial period. The ages of the flows will be determined at the bureau’s world-class Ar geochronology laboratory in the summer of 2019. The results of the first field season will guide drilling locations in the second field season currently schedule for December 2020.