Modelling of deformation and recrystallization microstructures in polar ice: FUMOPOLI/NUMOPOLI

极地冰变形和再结晶微观结构的建模：FUMOPOLI/NUMOPOLI

• 批准号: 76448837
• 负责人: Dr. Sergio H. Faria
• 金额: --
• 依托单位: Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/76448837?language=en
• 关键词: Modelling; deformation; recrystallization; microstructures; polar

During the last decades, the flow of large ice sheets has become one of the greatest issues in Earth and planetary sciences. As for our own planet, knowledge of the deformation mechanisms of polar ice is of crucial importance to predict the flow of polar ice caps and hence their influence on the global climate. Seeing that laboratory experiments cannot reproduce the slow and everlasting flow of polar ice sheets, most of our understanding of natural ice deformation comes from microstructural analyses of ice cores. Indeed, the microstructures seen in ice cores are invaluable records of the past in-situ deformation, although the unraveling of this complex deformation history remains a challenge for glaciologists. New techniques of microstructural analysis now allow a much more detailed and extensive assessment of these microstructures than ever before. The aim of this project is to develop theoretical and experimental methods to quantify the information encrypted in the vast and unique collection of photomicrographs available at AWI of several firn and ice cores, and in particular of the EPICA-DML2 deep ice core. Our ultimate objective is a critical reassessment the role of grain boundary formation and migration in several aspects of the microstructure evolution: the fading memory of deformation records, the evolution of anisotropy and the in-situ deformation mechanisms that control the flow of ice sheets.

在过去的几十年里，大冰盖的流动已经成为地球和行星科学中最大的问题之一。对于我们自己的星球来说，了解极地冰的变形机制对于预测极地冰盖的流动及其对全球气候的影响至关重要。鉴于实验室实验无法再现极地冰盖缓慢而持久的流动，我们对自然冰变形的大部分理解来自于对冰芯的微观结构分析。事实上，在冰芯中看到的微结构是过去原位变形的宝贵记录，尽管解开这一复杂的变形历史对冰川学家来说仍然是一个挑战。新的微结构分析技术现在可以对这些微结构进行比以往任何时候都更详细和更广泛的评估。该项目的目的是开发理论和实验方法，对AWI提供的大量独特的显微照片中加密的信息进行量化，这些照片收集了几个雪和冰芯，特别是EPICA-DML2深冰芯。我们的最终目标是重新评估晶界形成和迁移在微结构演化的几个方面所起的作用：变形记录的褪色记忆、各向异性的演化以及控制冰盖流动的原位变形机制。