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都有了显著的提高，揭示了地球材料在广泛的应力和温度条件下的丰富的流变和脆性行为。这些观测结果揭示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新的激动人心的机遇。拟议的研究活动将侧重于利用自然和人为变形源对地球岩石圈的流变和断裂特性进行跨学科研究。岩石圈对构造和火山载荷的响应方式多种多样，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性质仍然知之甚少。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化学过程是必不可少的，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已经获得了对岩石本构性质的重要见解，但将实验室测量结果外推到地壳尺度变形已被证明是困难的。拟议的研究将利用最新的进展（i）基于空间的大地测量观测地球，（ii）可用的计算能力，（iii）建模能力，以解决这些问题。从社会的角度来看，关于岩石变形机制的强有力的推论是重要的，因为它们直接关系到人口稠密的构造活动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.