CAREER: Frontiers of Continuum and Fracture Mechanics in Geology and Geophysics

在过去的几十年里，地球物理和大地测量观测的质量和数量的显著提高揭示了地球材料在大范围应力和温度条件下的丰富流变和脆性行为。这些观察结果暴露了现有变形理论的适用性局限性，并在地质力学领域开辟了令人兴奋的新机遇。拟议的研究活动将集中在利用自然和人为变形源对地球岩石圈流变学和断裂特性进行跨学科研究。岩石圈被认为以多种方式响应构造和火山荷载，从主要的弹性变形到脆性破坏、粘性蠕变和塑性屈服。然而，控制大规模变形的岩石的整体力学特性仍然知之甚少。关于岩石变形机制的详细知识对于理解一些基本的地质和地球物理过程是必不可少的，如地震周期、造山运动、岩石圈裂谷、火山活动等。虽然从实验室实验中获得了对岩石本构性质的重要见解，但从实验室测量结果推断地壳尺度的变形已被证明是困难的。拟议的研究将利用以下方面的最新进展：(i)基于空间的地球大地测量观测，（ii）可用的计算能力，以及（iii）建模能力来解决这些问题。从社会的角度来看，关于岩石变形机制的有力推断是重要的，因为它们直接关系到人口密集的构造活跃地区的地震和火山灾害问题。

Over the last decades, dramatic improvements in the quality andquantity of geophysical and geodetic observations revealed richrheologic and brittle behavior of the Earth materials under the widerange of stress and temperature conditions. These observations exposedthe applicability limits of the existing theories of deformation, andopened new exciting opportunities in the field of geologicalmechanics. The proposed research activities will focus oninterdisciplinary studies of the rheologic and fracture properties ofthe Earth's lithosphere using natural and man-made sources ofdeformation. The lithosphere is believed to respond to tectonic andvolcanic loads in a variety of ways, ranging from a predominantlyelastic deformation to brittle failure, viscous creep, and plasticyielding. However, the bulk mechanical properties of rocks that governthe large-scale deformation are still poorly known. Detailed knowledgeabout the mechanisms of rock deformation is essential forunderstanding a number of fundamental geological and geophysicalprocesses, such as the earthquake cycle, mountain building, rifting ofthe lithosphere, volcanic activity, etc. While significant insightsinto the constitutive properties of rocks have been obtained fromlaboratory experiments, extrapolations of the laboratory measurementsto the crustal-scale deformation have proven to be difficult. Theproposed research will take advantage of recent advances in (i)space-based geodetic observations of the Earth, (ii) availablecomputational power, and (iii) modeling capabilities to address theseproblems. Robust inferences about the mechanisms of rock deformationare important from a societal perspective, as they directly bear onthe issue of seismic and volcanic hazards in populated tectonicallyactive areas.