Meng Yue, Lai Ching-Yao, Culberg Riley, Shahin Michael G, Stearns Leigh A, Burton Justin C, Nissanka Kavinda
Department of Geophysics, Stanford University, Stanford, CA, USA.
Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, USA.
Nat Commun. 2025 Jan 10;16(1):573. doi: 10.1038/s41467-024-55241-7.
Iceberg calving is a major contributor to Greenland's ice mass loss. Ice mélange, tightly packed sea ice and icebergs, has been hypothesized to buttress the calving fronts. However, quantifying the mélange buttressing force from field observations remains a challenge. Here we show that such quantification can be achieved with a single field measurement: thickness of mélange at the glacier terminus. We develop a three-dimensional discrete element model of mélange along with a simple analytical model to quantify the mélange buttressing using mélange thickness data from ArcticDEM over 32 Greenland glacier termini. We observed a strong seasonality in mélange thickness: thin mélange (averaged thickness m) in summertime when terminus retreats, and thick mélange (averaged thickness m) in wintertime when terminus advances. The observed seasonal changes of mélange thickness strongly coincide with observed Greenland calving dynamics and the modeled buttressing effects.
冰山崩裂是格陵兰冰量损失的主要原因。冰混合体，即紧密堆积的海冰和冰山，被认为可以支撑崩裂前沿。然而，通过实地观测来量化混合体支撑力仍然是一项挑战。在这里，我们表明，这样的量化可以通过一项实地测量来实现：冰川末端混合体的厚度。我们开发了一个混合体的三维离散元模型以及一个简单的分析模型，以利用来自北极数字高程模型（ArcticDEM）的32个格陵兰冰川末端的混合体厚度数据来量化混合体支撑力。我们观察到混合体厚度存在强烈的季节性：夏季末端后退时混合体较薄（平均厚度 米），冬季末端前进时混合体较厚（平均厚度 米）。观测到的混合体厚度的季节性变化与观测到的格陵兰崩裂动态以及模拟的支撑效应强烈吻合。
