North American Plate Dynamics and Western U.S. Deformation

9903182汉弗莱斯研究人员将通过对施加在板块上的力进行建模，并将预测的应力与从正在进行的构造样式推断的应力和在钻孔中观察到的应力进行比较，来解决北美板块的动力学问题。采用有限元方法进行建模。应用于模拟北美的输入力将包括边界力和基准力，以及板块内部产生的力(由势能变化产生，如地形产生的势能变化)。将估计施加的力的相对大小，以考虑应力和变形信息。此外，由于北美施加的许多力的大小都是先验的(例如山脊推进)，因此所有施加的力的大小将受到很好的限制。构造应力使北美变形的速度与其强度成反比。强度将用粘性流变学建模，通过将计算的应力与(合理地众所周知的)应变率之比来估计。这项研究可以分为几个任务：1)输入场的估计，2)北美适当的有限元表示，3)模型预测与可观测的评估，以及4)随着建模的进展，朝着解析输入场和评估其唯一性的方向发展。

9903182 Humphreys The investigators will address North America plate dynamics by modeling the forces applied to the plate and comparing the predicted stresses with those inferred from the style of ongoing tectonics and those observed in drill holes. Modeling will be done with the finite element method. Input forces applied to modeled North America will include boundary and basal forces, and those generated internal to the plate (arising from potential energy variations such as those created by topography). The relative magnitudes of applied forces will be estimated to account for stress and deformation information. Furthermore, because the magnitude of many of the forces applied North America are well known a priori (such as ridge push), the magnitude of all the applied forces will be well constrained. Tectonic stresses deform North America at a rate inversely proportional to its strength. Strength will be modeled with a viscous rheology, which wil be estimated by ratioing the calculated stress with the (reasonably well-known) strain rate. This research can be divided into several tasks: 1) estimation of input fields, 2) description of an appropriate finite element representation of North America, 3) evaluation of model predictions against observables, and 4) as modeling progresses, toward resolving the input fields and assessment of their uniqueness.