Moss Reveals Past Hotspots of Rapid Glacier Change on Antarctic Peninsula

Geology, 20 January 2023

Researchers in the northern Antarctic Peninsula can use frozen moss samples to measure the growth and retreat of glaciers thousands of years ago, providing rare historical data in regions where other ice records have been lost. When a glacier advances, it covers the ground near its base in a layer of ice that suffocates plants. The date the plant died is the same time that the glacier advanced over that location. Analyzing layers of moss trapped in West Antarctic glaciers has enabled researchers to reconstruct glacier movement over centuries to millennia, allowing them to determine the size of the glacier at different dates. They found that glaciers in the Antarctic Peninsula advanced during three distinct phases over the past 1,500 years during periods of cooler temperatures. Most notably, their study shows that glaciers with the fastest rate of growth also had the fastest retreat, indicating that certain regions of the Antarctic Peninsula are more vulnerable to rapid ice loss than previously anticipated. This more comprehensive record of historical glacier dynamics will help researchers pinpoint which Antarctic regions are at higher risk of ice loss. As rising temperatures continue to destabilize the Peninsula’s ice, these findings underscore the importance of reducing emissions to prevent these polar regions from crossing irreversible thresholds, with related sea-level rise.

https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G50314.1/619980/Kill-dates-from-re-exposed-black-mosses-constrain