近日，英国剑桥大学David Wallis团队研究了地球上地幔的柔性-野生可塑性。2026年2月9日，《自然—地球科学》杂志发表了这一成果。

长期以来，地球地幔上部的流动一直被认为是通过缓慢、近乎连续的蠕变进行的。这种行为在经典的高温变形实验中被观察到，并且是地球动力学模型的基本组成部分。然而，新一代的高分辨率实验揭示，从金属到冰等多种材料都表现出一种被称为“柔性-野生可塑性”的行为谱系，其范围从温和的连续流动到塑性应变率的间歇性剧烈波动。

研究组通过纳米压痕实验表明，即使在预期其行为相对温和的条件下，橄榄石仍表现出可测量的“野生性”。具体而言，在室温下对橄榄石单晶的实验中，连续的塑性流动被间歇性的位移爆发所打断，这些位移爆发呈现对数正态分布的幅度，表明存在相关位错运动的雪崩，约占塑性应变的~8 ± 6%。

“柔性-野生可塑性”理论框架预测，在地球内部，“野生性”应随深度增加而增强，软流圈的流动几乎完全由颗粒尺度上变形的剧烈波动所主导。认识到地质材料中的间歇性塑性行为，为位错介导流动的模型提供了新的约束，并对其他韧性区域中瞬态失稳机制（如深源地震和慢滑移事件）提出了新的问题。

附：英文原文

Title: Mild-to-wild plasticity of Earth’s upper mantle

Author: Wallis, David, Kumamoto, Kathryn M., Breithaupt, Thomas

Issue&Volume: 2026-02-09

Abstract: Flow of Earth’s upper mantle has long been considered to occur by slow, near-continuous creep. This behaviour is observed in classical high-temperature deformation experiments and is a fundamental component of geodynamic models. The latest generation of high-resolution experiments, however, have revealed that materials ranging from metals to ice exhibit a spectrum of behaviours, termed mild-to-wild plasticity, that range from this mild continuous flow to intermittent wild fluctuations in plastic strain rate. Here we show, using nanoindentation experiments, that olivine exhibits measurable wildness, even under conditions at which its behaviour is expected to be relatively mild. Specifically, during experiments on olivine single crystals at room temperature, continuous plastic flow is punctuated by intermittent bursts of displacement with log-normally distributed magnitudes, indicating avalanches of correlated dislocation motion that account for ~8±6% of the plastic strain. The framework of mild-to-wild plasticity predicts that wildness should increase with depth in Earth, with flow of the asthenosphere occurring almost entirely by wild fluctuations of deformation at the grain scale. The recognition of intermittent plasticity in geological materials provides additional constraints on models of dislocation-mediated flow and raises questions about the mechanisms of transient instabilities in otherwise ductile regimes, such as deep earthquakes and slow-slip events.

DOI: 10.1038/s41561-026-01920-7

Source: https://www.nature.com/articles/s41561-026-01920-7