When ice disappears, new coastlines are born
Current climate change rapidly reduces the glacier area in the Northern Hemisphere, including marine-terminating glacier areas in the Arctic and subarctic regions. As a result of this process, vast areas of new coastlines that were previously inaccessible to scientists are now being exposed. An international group of scientists from Poland, the Czech Republic, the United States, and Canada has united in an initiative, supported by a grant from the National Science Centre, to address the knowledge gap concerning coastlines that have emerged due to glacial recession in the 21st century.
By comparing a new glaciological database with satellite images of all marine-terminating glaciers in the Northern Hemisphere, researchers discovered that glacier recession between 2000 and 2020 led to the formation of nearly 2,500 km of new coastline. This implies that, on average, the length of the new coastline expands by more than 120 km each year. Greenland, which is covered by the only ice sheet in the Northern Hemisphere, accounts for two-thirds of this increase. During the same period, just over 50 km of coastline became covered by glaciers. Additionally, 35 large islands were identified as having been revealed by glacial retreat, with 13 of them documented for the first time.
The study’s results were published on March 21, 2025, in Nature Climate Change – the world’s leading forum for scientific debate on climate change: https://www.nature.com/articles/s41558-025-02282-5.
Mgr Małgorzata Szczypińska, a doctoral researcher in the GLAVE project at the Alfred Jahn Cold Regions Research Centre at the University of Wrocław,and a co-author of the article, adds that, in addition to the inventory work it was also examined whether the length of newly formed coastlines is proportional to changes in glacier area. Significant differences were found between individual glaciers as well as across different regions. Researchers discovered that the glaciers of Baffin Island, Alaska, and southeastern Greenland are much more effective at creating new coastlines compared to those in other regions. In contrast, on the Russian Arctic islands, although a significant area was exposed due to glacier retreat, relatively few new coastlines were formed.
Dr. Jan Kavan from the Centre for Polar Ecology at the University of South Bohemia in České Budějovice, a former postdoctoral researcher at the University of Wrocław, emphasised the importance of open-access databases as essential tools for modern research on how cold-region environments are responding to ongoing climate warming.
Prof. Mateusz Strzelecki, head of the National Science Centre grant GLAVE – Paraglacial coasts transformed by tsunami waves – past, present, and warmer future, under which the analyses for this study were conducted, highlights the significance of the presented findings for the research of the Arctic coasts. In recent years, there has been a renaissance in Arctic coastal research, particularly focusing on the rapidly eroding permafrost coasts of northern Alaska, the Yukon, and Siberia. However, little information has been available about glaciated coastlines in Arctic regions such as Greenland, the Canadian Arctic Archipelago, and Svalbard. Therefore, our study opens a new chapter in the exploration of the world’s youngest coastlines. These 2,500 km of coastlines, which had been covered by glaciers for at least several centuries, are places where waves and tides reshape glaciers into new coasts, sandspits, lagoons, and cliffs. It is also important to remember that the steep shores of fjords, recently exposed by glacial retreat, pose a danger due to the risk of rockfalls that can trigger powerful tsunamis or landslides. In recent years, such waves have been recorded in Alaska and Greenland, originating from destabilised coastlines where glaciers had only recently retreated.
To illustrate the potential for further development of newly exposed coastlines, an analysis of substrate quality and local climate conditions was conducted. The longest stretches of coastlines most prone to weathering and erosion, that is, formed in sedimentary rocks, were shredded along the eastern coasts of Svalbard, Alaska and the northern borders of Greenland. These newly exposed coastlines represent a unique phenomenon in the permafrost world—over 50% of the coastlines documented in the study have emerged in regions characterised by continuous permafrost. The authors hope that their article will inspire new research on the rate of permafrost aggradation along glacier-free coastlines, which, for example, could lead to the accumulation of permafrost around buried remnants of glacial ice.
The research was funded by the National Science Centre in Poland as part of the GLAVE project, which aims to improve the understanding of paraglacial coastal environments affected by extreme waves triggered by cryosphere degradation.
Translated by Valiantsina Trafimuk (student of English Studies at the University of Wrocław) as part of the translation practice.
Date of publication: 21.03.2023
Added by: M.J.
