Evolution of supraglacial lakes over the pan-Antarctic ice sheet between 2014 and 2022: Assessment and the control factors

Abstract

Widespread supraglacial lakes (SGLs) across the Antarctic surface can accelerate land ice flow and be linked to ice shelf disintegration, further affecting sea-level rise projections. However, previous studies usually focused on SGLs at regional scale or some typical ice shelves, and underestimated the distribution and area of SGLs. Thus, the current Antarctic-wide SGL distribution and variability information is still limited, and the present status and possible influence on ice shelf stability are also largely unknown. Here, we used more than 110,000 Landsat 8 images to detect SGLs across Antarctica (north of 83°S) in austral summer from 2014 to 2022 by using a well-constructed threshold-based method. Overall, most SGLs were located on ice shelves, covering 79% of the total area; the largest SGL areas were found in East Antarctica (79%, 2222 km2), far exceeding the SGL areas in Antarctic Peninsula (20%, 473 km2) and West Antarctica (1%, 23 km2). SGL area gains and declines were found in the Antarctic Peninsula and West Antarctica, respectively, while East Antarctica experienced relatively high interannual variabilities due to the presence of some ice shelves with asynchronous variation patterns. Larger collapse risks are found for smaller ice shelves; ice shelves in East Antarctica are relatively unstable, and disintegration risk is increasing for some ice shelves in Antarctic Peninsula. Glaciological factors are closely related to the location of SGLs, and temperature, precipitation and winds are strongly linked to SGL evolution. This study is expected to enhance the reliability of existing Antarctic SGL dataset by providing a more comprehensive dataset, and offer detailed insights into the relationship between SGLs, climatic factors, and near-surface conditions. Additionally, it examines the risks of ice shelf collapse caused by SGLs, which is essential for understanding the SGL dynamics and their impacts.

Keywords

• Supraglacial lakes
• Spatio-temporal variation
• Ice shelf collapse risk
• Antarctica