North America Dynamics and Western U. S. Deformation

Eugene D.汉弗莱斯研究人员通过模拟施加在板块上的力，并将预测的应力与从正在进行的构造样式中推断的应力以及钻孔中观察到的应力进行比较，来解决北美板块动力学问题。 用有限元法进行建模。 输入力施加到模拟的北美包括边界和基础的力量，和那些内部产生的板块（由势能变化，如地形造成的）。施加的力量的相对大小估计占应力和变形信息。 此外，由于许多作用在北美的力的大小是先验已知的（如脊推），因此所有作用力的大小都将受到很好的约束。 构造应力使北美变形的速度与其强度成反比。研究人员用粘性流变学来模拟强度，他们通过计算应力与（合理地众所周知的）应变率。该研究可以分为几个任务：输入场的估计，北美的适当有限元表示的描述，对可观测量的模型预测的评估，随着建模的进展，我们将解决输入字段并评估其唯一性。

EAR-0106892Eugene D. HumphreysThe investigators address North America plate dynamics by modeling the forces applied to theplate and comparing the predicted stresses with those inferred from the styleof ongoing tectonics and those observed in drill holes. Modeling is done withthe finite element method. Input forces applied to modeled North Americainclude 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 are estimated to account for stressand deformation information. Furthermore, because the magnitude of many of theforces applied North America are well known a priori (such as ridge push), themagnitude of all the the applied forces will be well constrained. Tectonicstresses deform North America at a rate inversely proportional to its strength.The investigators model strength with a viscous rheology, which they estimate by ratioing thecalculated stress with the (reasonably well known) strain rate.The research can be divided into several tasks: estimation of input fields,description of an appropriate finite element representation of North America,evaluation of model predictions against observables, and as modeling progressestoward resolving the input fields and assessment of their uniqueness.--