A recent study published in the journal Science Advances provides crucial insights into the state of Antarctica’s ice shelves over 25 years, from 1997 to 2021. The research reveals that out of the 162 ice shelves surrounding Antarctica, 71 experienced a reduced volume, leading to a net release of 7.5 trillion metric tons of meltwater into the oceans. Ice loss was predominantly observed in the western side of Antarctica, influenced by warmer ocean temperatures, while the eastern side’s ice shelves generally remained stable or even increased in volume.

Dr. Benjamin Davison, who led the study at the University of Leeds, emphasizes that this ice-shelf deterioration is linked to ocean temperatures and currents around Antarctica. The western region, exposed to warmer water, faces rapid ice erosion from below. On the other hand, much of East Antarctica is shielded by a band of cold water along the coast, preserving its ice shelves. Human-induced global warming is a significant factor contributing to the ice loss, as natural climate variations would likely have shown signs of ice regrowth on the western ice shelves.

Ice shelves acting as “plugs” at the end of glaciers are crucial in regulating ice flow into the oceans. Thinning or reducing these ice shelves weakens this regulatory function, accelerating the rate of ice loss from the glaciers. Some of the most substantial ice losses occurred on the Getz Ice Shelf and the Pine Island Ice Shelf, primarily due to melting at the base of the ice shelves. In contrast, the Amery Ice Shelf on the eastern side of Antarctica gained ice due to its isolation from warmer waters.

The research underscores the importance of monitoring the health of Antarctica’s ice shelves, as their stability is intricately linked to the broader climate system and global ocean circulation. The freshwater released into the ocean from these ice shelves can disrupt ocean circulation by diluting salty water and hindering its ability to sink, affecting the global climate system. As the climate continues to warm, the study provides a critical baseline to track further changes in Antarctica’s ice shelves, highlighting the urgency of addressing climate change. This comprehensive analysis was made possible through satellite monitoring, providing detailed insights into year-by-year changes in Antarctica’s ice shelves and contributing to our understanding of these vital components of the polar ecosystem.

References

• Davison, B. J. et al. Annual mass budget of Antarctic ice shelves from 1997 to 2021. Science Advances 9, eadi0186 (2023). DOI:10.1126/sciadv.adi0186
• University of Leeds. (2023, October 12). Over 40% of Antarctica’s ice shelves reduced in volume over 25 years, scientists say. Phys.Org. https://phys.org/news/2023-10-antarctica-ice-shelves-volume-years.html