研究结果显示，在格陵兰冰盖上，钻孔光纤观测揭示了一种脆性变形模式，这种模式与长度尺度上的粘滞流动不相容，与现代冰盖模型分辨率相似：在地表无法观测到的冰川冰震级联。它们在火山相关杂质附近成核，促进晶界开裂，表现为晶体尺度野生塑性的宏观形式。
研究保守估计，地震级联可能产生的应变率的振幅与测地测量的应变率相当，从而在目前的冰盖模型和观测之间提供了一个可能缺失的联系。
据悉，冰流是海平面变化的主要调节者。然而，人们对其相关过程的理解不完全，对标准黏液流动模拟的预测能力有限。
附：英文原文
Title: Hidden cascades of seismic ice stream deformation
Author: Andreas Fichtner, Coen Hofstede, Brian L. N. Kennett, Anders Svensson, Julien Westhoff, Fabian Walter, Jean-Paul Ampuero, Eliza Cook, Dimitri Zigone, Daniela Jansen, Olaf Eisen
Issue&Volume: 2025-02-06
Abstract: Ice streams are major regulators of sea level change. However, standard viscous flow simulations of their evolution have limited predictive power due to incomplete understanding of involved processes. On the Greenland ice sheet, borehole fiber-optic observations reveal a brittle deformation mode that is incompatible with viscous flow over length scales similar to the resolution of modern ice sheet models: englacial ice quake cascades that are unobservable at the surface. Nucleating near volcanism-related impurities that promote grain boundary cracking, they appear as a macroscopic form of crystal-scale wild plasticity. A conservative estimate indicates that seismic cascades are likely to produce strain rates that are comparable in amplitude to those measured geodetically, thereby providing a plausible missing link between current ice sheet models and observations.
DOI: adp8094
Source: https://www.science.org/doi/10.1126/science.adp8094