The Route to Fractals in Magnetotelluric Exploration of the Crust

Down to Earth With Nuclear Electromagnetic Pulse: Realistic Surface Impedance Affects Mapping of the E3 Geoelectric Hazard

“…In other settings, tectonic forces have shaped terranes by faulting, deformation, and intrusion, resulting in structure that is fundamentally two-or three-dimensional. In such settings, subsurface conductivity structure and surface impedance can differ significantly across a wide range of geographic scales [e.g., Bahr , 2005;Lovejoy and Schertzer , 2007].…”

“…In other settings, tectonic forces have shaped terranes by faulting, deformation, and intrusion, resulting in structure that is fundamentally two‐ or three‐dimensional. In such settings, subsurface conductivity structure and surface impedance can differ significantly across a wide range of geographic scales (e.g., Bahr, 2005; Lovejoy & Schertzer, 2007). Although the shortest of these scales is limited by diffusion, Equation , site‐to‐site differences in impedance strongly affect E3 local geoelectric field, Equation .…”

Scaling and multifractal fields in the solid earth and topography

“…This term originates in the ubiquitous noise in electrical circuits (due for example to contacts) with similar spectra. Indeed, Leary (1997) has argued that the β's of sonic velocities, rock densities, H 2 density (porosity), gamma activity and resistivity, porosity and permeability are all approximately unity (although with fluctuations of order 0.2-0.4) and he has argued that this could best be understood from a phase transition type mechanism such as percolation (for an introduction, see Stauffer, 1985, for applications to rock conductivity see Bahr, 2005, and references therein). The obvious problem with this as a general explanation is that in phase transitions, unless 3/28/07 10 one happens to be exactly at the critical point there will only be scaling over a finite range of scales with a drastic breakdown for larger scales.…”

“…Also, the mantle regime has been briefly discussed in Lovejoy et al (2005) and on the basis of an analysis of the equations of mantle convection, the parameters s=3, H z =3 were proposed. Before leaving the topic of geopotentials, we could mention recent work by Bahr (2005) to link rock conductivity with electric fields. A final example of scaling geofields linked by linear equations is the thermal properties of the earth's crust: the thermal conduction coefficient, the temperature and the distribution of radioactive sources of heat, see Dimri and Vedanti (2005).…”