Annual trajectory of global glacial lake variations and the interactions with glacier mass balance during 2013–2022

Abstract

Global warming accelerates glacier melting and the growth of glacial lakes. Existing research on glacial lake changes primarily concentrates on specific regions or decadal timescales, impeding a comprehensive understanding of the spatial and temporal variation of glacial lakes. This study tracks the annual evolution of global glacial lakes larger than 1 km² (totally 3,133) from 2013 to 2022 based on Landsat OLI imagery. We investigated the lake area variation and glacier mass balance to explore interactions between glacial lake expansion and glacier mass loss. We aim to reveal the potentially diverse changes in the area of glacial lakes in various regions and of different types over the past decade. Our results show that, for the study glacial lakes, the total area has increased remarkably from 14,612 ± 21.13 km² to 15,034 ± 18.54 km² from 2013 to 2022. Among them, the glacier-contacted lakes experienced a rapid increase from 6,220 km² to 6,625 km², contributing to ∼ 96 % of the net area increment of the glacial lakes worldwide, whereas non-glacier-contacted lakes remain relatively stable at approximately 8,400 km². Overall, glacier-contacted lakes grew relatively fast in the sub-periods of 2013–2014 and 2018–2019 and maintained slightly slow growth in other years. Remarkable expansion of glacial lakes was observed in Alaska, Iceland, and New Zealand. The significant expansion of glacier-contacted lakes was primarily attributed to the water inundation sprawl upward to the glacier tongues, which accelerated melting rates of the mother glaciers as feedback. Our analysis of the trend and inter-annual variation of glacial lake area reveal contrasting evolution of glacial lakes in different regions and of different types, which serves as a key reference for comprehending the impact of climate change, the interaction between glaciers and glacial lakes, and mitigating natural disasters like glacial lake outbursts.