Supraglacial lake expansion, intensified lake drainage frequency, and first observation of coupled lake drainage, during 1985–2020 at Ryder Glacier, Northern Greenland

Abstract

Along the Greenland Ice Sheet margin, supraglacial lakes store and redistribute ice sheet surface run off, and comprise an important potential hydrological link between the ice surface and the base, with ramifications for subglacial drainage systems and ice flow. As a consequence of increasing global mean surface air temperatures, these lakes have been predicted to expand further inland and to affect larger areas of the ice sheet. However, as contemporary dynamics of such supraglacial lake expansion are not well studied, any assessment of their future implications remains afflicted with uncertainty. Here, recent changes in supraglacial lake distribution and expansion, and in their drainage behavior and frequency, are presented for Ryder Glacier, Northern Greenland, as concluded from a remote sensing based analysis. The 35-year time span covered in the analysis allows for the detection of trends in lake processes and ice velocity, which otherwise were found to exhibit large inter-annual variability. It also reveals the first occurrence of a coupled lake drainage event in 2002. By linking supraglacial lake expansion, drainage modes, and drainage frequency to the efficiency of the subglacial drainage system and ice flow on seasonal and decadal timescales, a contribution is made to better understand the complexity of coupled glacio-hydrological processes, and to help reduce uncertainties in predictions of future mass loss from the Greenland Ice Sheet.

Future runoff increase may destabilize Petermann ice shelf

“…In addition, ice shelf collapses due to hydrofracturing and Ćexurally-induced fractures resulting from supraglacial lake drainage events have also been noted (Scambos et al, 2009;Banwell and MacAyeal, 2015;Dow et al, 2018). However, unlike Greenland (Forster et al, 2014;Willis et al, 2015;Otto et al, 2022) there is no evidence of surface meltwater inĄltrating to the bed. GreenlandŠs surface and subglacial hydrological systems that are connected by drainage pathways offer a blueprint for understanding how Antarctica might evolve in a warmer world, as its surface hydrology starts to resemble present conditions observed at GrIS (Bell et al, 2018).…”

Seasonal evolution of the supraglacial drainage network at Humboldt Glacier, North Greenland, between 2016 and 2020

“…Earth-observing satellites enable the study of supraglacial drainage features with broad spatial and temporal coverages (Rennermalm et al, 2013;Yang and Smith, 2012;Chu, 2014). Over the last four decades, the Landsat program has provided a wealth of remotely-sensed data for the mapping and quantification of a number of supraglacial features such as SGLs (Lampkin and Vanderberg, 2011;Pope et al, 2016;Gledhill andWilliamson, 2017, 2018;Yang et al, 2019b;Otto et al, 2022), as well as for exploring the generalised configuration (i.e., main river stems) of the supraglacial drainage system (Lampkin and Vanderberg, 2014;Yang et al, 2021). But, its spatial resolution in the visible spectrum (30 m) precludes the reliable delineation of numerous smaller supraglacial rivers (Yang et al, 2019a).…”