近日，科罗拉多大学波德分校Zhong, Shijie团队研究了冰川强迫对岩石圈运动和山脊扩张的影响。这一研究成果于2025年4月23日发表在《自然》杂志上。

冰川周期在整个第四纪期间对地球表面过程产生了重大影响，影响了气候、海平面以及地震和岩浆活动。然而，冰川作用和冰消作用（即冰川强迫）对岩石圈运动的影响尚不清楚。为了研究这些影响，课题组构建了具有真实岩石圈结构的高分辨率数值模型，包括弱板块边缘、岩石圈厚度变化和地壳结构。该结果表明，在上一个冰川周期中，冰川强迫显著改变了位于主要冰盖附近的岩石圈运动和洋中脊的扩张速率。

例如，在10000年的时间尺度上，北美板块的冰消运动引起的运动有一个旋转部分，高达其构造板块运动的25%左右。在12000年至6000年前，格陵兰岛和芬诺斯坎迪亚的冰川消融导致冰岛海脊的扩张速度波动高达40%，这可能解释了冰岛的全新世火山活动。该模型还表明，在冰川作用期间，全球海底产量增加（减少），这对地幔脱气速率有影响。这些结果强调了冰河时代冰川周期、岩石圈运动、脊扩张和气候之间的关键动态相互作用。

附：英文原文

Title: Effects of glacial forcing on lithospheric motion and ridge spreading

Author: Yuan, Tao, Zhong, Shijie

Issue&Volume: 2025-04-23

Abstract: Glacial cycles significantly influenced Earth’s surface processes throughout the Quaternary, impacting the climate, sea level, and seismic and magmatic activity1,2,3. However, the effects of glaciation and deglaciation (that is, glacial forcing) on lithospheric motion are unknown. To study these effects, we formulated high-resolution numerical models with realistic lithospheric structures, including weak plate margins, lithospheric thickness variations and crustal structure. Our results show that glacial forcing significantly altered lithospheric motion and the spreading rates of mid-ocean ridges situated near major ice sheets in the last glacial cycle. For example, deglaciation-induced motion in the North American plate had a rotational part that was up to around 25% of its tectonic plate motion over 10,000-year timescales. The deglaciation in Greenland and Fennoscandia caused up to 40% fluctuations in the spreading rates of the Iceland Ridge between 12,000 and 6,000 years ago, which may explain the Holocene volcanism in Iceland. Our modelling also indicates increased (decreased) rates of global sea-floor production during the deglaciation (glaciation) periods with implications for mantle degassing rates. These results underscore the critical dynamic interplay between glacial cycles, lithospheric motion, ridge spreading and climate during ice ages.

DOI: 10.1038/s41586-025-08846-x

Source: https://www.nature.com/articles/s41586-025-08846-x