近日，美国科罗拉多州立大学Daniel McGrath团队报道了由于冰川通过河床过度加深而退缩，阿拉斯加冰缘湖迅速增长。2026年3月9日出版的《国家科学评论》杂志发表了这项成果。

近几十年来，全球冰缘湖泊的数量与累计面积持续扩张，这些湖泊多发育于冰川侵蚀作用优先形成的冰下盆地——冰川下覆盆地之中。然而，当前对湖泊扩张速率、关键驱动因子及未来最大扩展范围的认识仍较为薄弱。这一问题的重要性在于：冰缘湖泊不仅构成灾害风险源，改变水文与生态系统，某些情况下还会加速冰川运动与退缩。

研究组量化了阿拉斯加地区近期冰缘湖泊的扩张过程，并利用现有冰厚与地形数据绘制冰川下覆盆地分布图，以此作为预测近期及未来湖泊扩张位置的指示因子。数据显示，2018-2024年间该区域冰缘湖泊面积增加了156平方公里（年均26平方公里），较2009-2018年扩张速率提升50%。自2018年以来，80%的湖泊扩张发生于已绘制的冰川下覆盆地内。当前与冰缘湖泊相连的下覆盆地面积约4250平方公里（考虑冰厚不确定性后范围为2966-5503平方公里），表明随着冰川退缩，现有湖泊的扩展潜力可达四倍以上。

此外，尚有14500平方公里（12469-17134平方公里）的现存冰川覆盖于未连接湖泊的冰下盆地之上，预示着未来可能形成大量新生湖泊。末端有湖泊的冰川流速呈现出冰川-湖泊耦合作用连续谱系中的明确被动端元与动力端元特征。发育冰缘湖泊的冰川其消融速率比同等面积的无湖冰川高出23-54%，这凸显了冰川-湖泊动态耦合作用对阿拉斯加冰川演化进程的关键影响。

附：英文原文

Title: Rapid ice-marginal lake growth in Alaska driven by glacier retreat through bed overdeepenings

Author: McGrath, Daniel, Sass, Louis, Armstrong, William H., Florentine, Caitlyn, McCoy, Scott W.

Issue&Volume: 2026-3-9

Abstract: The number and cumulative area of ice-marginal lakes have expanded globally in recent decades, with many lakes residing in glacier-bed overdeepenings, which are subglacial basins formed through preferential glacial erosion. However, current lake expansion rates, key drivers of expansion, and maximum future lake extents are poorly quantified. This is notable because glacial lakes pose hazards, alter hydrologic and ecological systems, and, in some cases, accelerate glacier flow and retreat. Here, we quantify recent ice-marginal lake growth and use existing ice thickness and topographic data to map glacier-bed overdeepenings in Alaska as a predictor of recent and future locations of lake growth. Ice-marginal lakes in the region grew by +156 km2 (26 km2 y1) between 2018 and 2024, representing a 50% increase relative to the 2009–2018 rate. Eighty percent of lake growth since 2018 occurred in mapped glacier-bed overdeepenings. Approximately 4,250 km2 (2,966 to 5,503 km2 accounting for ± ice thickness uncertainty) of the overdeepened area is connected to an ice-marginal lake, indicating the potential for more than fourfold lake growth of existing lakes as glaciers retreat. An additional 14,500 km2 (12,469 to 17,134 km2) of remaining glacier area resides on glacier-bed overdeepenings not connected to existing lakes, highlighting the potential for substantial new lake development. Velocities from lake-terminating glaciers show clear passive and dynamic endmembers on a continuum of glacier–lake coupling. Glaciers with ice-marginal lakes thinned 23 to 54% more than glaciers of similar area without lakes, underscoring the critical importance of dynamic glacier–lake coupling on the evolution of glaciers in Alaska.

DOI: 10.1073/pnas.2513289123

Source: https://www.pnas.org/doi/abs/10.1073/pnas.2513289123