Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till

该奖项支持一个项目，该项目旨在进行实验室实验和数值模拟，以确定冰川下耕作在动态应力下的本构特性，并测试这样一个假设，即当冰耕与大冰流弹性耦合时，冰耕的颗粒特性足以重现触发滑动和冰下地震活动的现场观测。试验将在伺服控制的双轴剪切装置中进行，在受控的温度和应力条件下进行，这将允许详细研究滑动和微观结构过程。这项工作的主要重点将是实验室测量。此外，我们将构建连续介质模型来评估我们的结果是否能够预测复杂的冰盖运动和观测到的冰下地震活动特征。在更广泛的影响方面，拟议的工作将鼓励岩石力学和冰川学社区之间的互动，并将把具有不同科学背景和词汇、但问题和数据相似的成员聚集在一起。该项目将培训宾夕法尼亚州立大学的本科生和研究生，参与其中的科学家计划在小学班级、童子军团体和社区开放日上发表演讲。结果将在专业会议上公布，并将及时公布。这项工作将导致更好地理解冰川运动和地震滑动的物理学，这对于理解冰盖动力学和地震危险是必不可少的。

0538195MaroneThis award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard.