Collaborative Research: Electromagnetic Induction in Geological Formations: A Careful Evaluation of the Subdiffusion Perspective

团队1建议编号：09-43598主要调查者：Weiss，Chester；540-231-3651；cjweiss@vt.eduInstitution：弗吉尼亚理工队2建议编号：09-43589主要调查者：Everett，Mark；979-862-2129；Everett@Geo.TamueduInstitution：Texas A&Amp；MTitle：A仔细评估次扩散视角ABSTRACT虽然可控源电磁地球物理经常被誉为地下电磁水文学的潜在突破性技术，但目前的现实是，水文地质学家在解释电磁数据方面经常遇到严重的困难。在简单的情况下，地下表面的电性可以合理地近似为光滑的或分段恒定的分布，在限制我们对水文系统的知识方面，低频电磁感应的经典地球物理方法是有用的。然而，在环境更复杂的情况下？例如，地下的特征是依赖于长度尺度的非均质性？经典的电磁感应方法必须作相应的修改。一种很有前途的分析方法使用了分数微积分的历史方法，以适应控制麦克斯韦方程中随尺度变化的岩性复杂性。通过对分数麦克斯韦响应(FMR)和相应复杂程度的经典电磁模拟的系统研究，我们旨在阐明存在分数麦克斯韦响应的地质环境，并从孔隙度、粘土含量、孔隙水矿化度、裂缝密度、盐楔或污染带的位置等水文参数来解释分数麦克斯韦响应。本方案的技术创新基于将传统电磁地球物理扩展到新的领域，发展了电磁场向尺度相关地质介质的异常扩散。然而，广泛的电磁地球物理学，无论是传统的还是创新的，都必须更好地向水文界传达。因此，我们计划利用新开发的虚拟研究所OpenEM.org？作为一个平台，使水文界更好地参与电磁地球物理的应用。

Team 1Proposal Number: 09-43598Principal Investigator: Weiss, Chester; 540-231-3651; cjweiss@vt.eduInstitution: Virginia TechTeam 2Proposal Number: 09-43589Principal Investigator: Everett, Mark; 979-862-2129; everett@geo.tamu.eduInstitution: Texas A&MTitle: Electromagnetic Induction in Geological Formations: A Careful Evaluation of the Subdiffusion Perspective ABSTRACTWhile controlled-source electromagnetic geophysics has been often hailed as a potential breakthrough technology for subsurface hydrology, the current reality is that hydrogeologists often experience severe difficulties in interpreting electromagnetic data. In simple cases, where the electrical properties of the subsurface are reasonably approximated by a smooth or piecewise-constant distribution, classical geophysical methods of low-frequency electromagnetic induction are useful in constraining our knowledge of the hydrologic system. However, in cases where the setting is more complicated ? for instance, where the subsurface is characterized by length-scale-dependent heterogeneity ? the classical methods of electromagnetic induction must be modified accordingly. A promising analytic approach uses the historical methods of fractional calculus to accommodate scale-dependent lithologic complexity in the governing Maxwell Equations. Through a systematic study of the fractional Maxwell response (FMR) and corresponding classical electromagnetic simulations of appropriate complexity, we aim to illuminate geological settings where the FMR is present and to interpret the FMR in terms of hydrologic parameters such as porosity, clay content, pore water salinity, fracture density, position of a saline wedge or contaminant zone, etc. The technical innovation of our current proposal is based on extending traditional electromagnetic geophysics into new territory with the development of anomalous diffusion of electromagnetic fields into scale-dependent geological media. The broad sweep of electromagnetic geophysics, both traditional and innovative, must however be better communicated to the hydrological community. Accordingly we plan to utilize the newly developed virtual institute ?OpenEM.org? as a platform to better engage the hydrologic community in the application of electromagnetic geophysics.