Vertical Land Motion Due To Present‐Day Ice Loss From Greenland's and Canada's Peripheral Glaciers

• Published in: Geophysical research letters 2024-01, Vol.51 (2), p.n/a
• Main Authors: Berg, D., Barletta, V. R., Hassan, J., Lippert, E. Y. H., Colgan, W., Bevis, M., Steffen, R., Khan, S. A.
• Format: Article
• Language: English
• Subjects: Ablation; Bedrock; Climate change; Climate change causes; Deformation; Deformation analysis; Deglaciation; Earth; Glacial periods; Glaciation; Glaciers; Global navigation satellite system; Ice ages; Ice caps; Ice sheets; Meltwater; Navigation; Navigation satellites; Navigation systems; Navigational satellites; Satellites; Viscoelasticity
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2023GL104851

Greenland's bedrock responds to ongoing ice loss with an elastic vertical land motion (VLM) that is measured by Greenland's Global Navigation Satellite System (GNSS) Network (GNET). The measured VLM also contains other contributions, including the long‐term viscoelastic response of the Earth to the deglaciation of the last glacial period. Greenland's ice sheet (GrIS) produces the most significant contribution to the total VLM. The contribution of peripheral glaciers (PGs) from both Greenland (GrPGs) and Arctic Canada (CanPGs) has not carefully been accounted for in previous GNSS analyses. This is a significant concern, since GNET stations are often closer to PGs than to the ice sheet. We find that, PGs produce significant elastic rebound, especially in North and East Greenland. Across these regions, the PGs produce up to 32% of the elastic rebound. For a few stations in the North, the VLM from PGs is larger than that due to the GrIS. Plain Language Summary The solid Earth has long been compressed by the weight of overlying ice caps and ice sheets. As climate change causes ice to melt, and these loads diminish, the solid Earth relaxes, producing instantaneous elastic rebound and delayed viscoelastic rebound of the bedrock. Such displacements are recorded by the 58 permanent Global Navigation Satellite System (GNSS) stations that comprise the Greenland GNSS Network (GNET). So far, only the ice mass changes from the ice sheet have been considered in the analyses of deformation recorded by GNET. Here, we evaluate the contribution from the peripheral glaciers, which are often much closer to the stations than the ice sheet. We find that at many stations, the signal produced by the peripheral glaciers is non‐negligible, especially in North and East Greenland. This allows us to better understand the residual rebound signal produced by the end of the last ice age. Key Points Elastic rebound due to ice loss from peripheral glaciers can exceed that due to ice sheet loss This effect is most significant at Global Navigation Satellite System Network (GNET) sites in North and East Greenland Peripheral glacier loss should be acknowledged when isolating glacial isostatic adjustment from GNET