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

职业：地质学和地球物理学中的连续体和断裂力学前沿

• 批准号: 0450035
• 负责人: Yuri Fialko
• 金额: $ 50.8万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-12-15 至 2009-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0450035&HistoricalAwards=false
• 关键词: CAREER; Frontiers; Continuum; Fracture; Mechanics

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.

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着提高揭示了地球材料在广泛的应力和温度条件下丰富的流变性和脆性行为。这些观察结果暴露了现有变形理论的适用局限性，并在地质力学领域开辟了新的令人兴奋的机会。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。人们认为岩石圈以多种方式响应构造和火山载荷，从主要的弹性变形到脆性破坏、粘性蠕变和塑性屈服。然而，人们对控制大规模变形的岩石的整体力学特性仍然知之甚少。有关岩石变形机制的详细知识对于理解许多基本地质和地球物理过程至关重要，例如地震周期、造山、岩石圈裂谷、火山活动等。虽然通过实验室实验获得了对岩石本构特性的重要见解，但事实证明，将实验室测量结果外推到地壳尺度的变形是很困难的。拟议的研究将利用（i）基于空间的地球大地测量观测、（ii）可用的计算能力和（iii）建模能力的最新进展来解决这些问题。从社会角度来看，关于岩石变形机制的可靠推论非常重要，因为它们直接关系到人口稠密的构造活动地区的地震和火山灾害问题。