Ceddes, noticed in the case of a number of aurorae that the earth currents
which accompanied the displays and seriously interfered with telephonic and telegraphic communication frequently began on the afternoon preceding the auroral display.
Faults are electromagnetic hot zones where electrical currents from the atmosphere are interacting with the subsurface currents called telluric or Earth currents. All of this is detrimental for pipelines and storage facilities, as well, and lightning is a new key to understanding how to identify what areas need to have additional cathodic protection.
The strike locations appear to be controlled more by geologically driven Earth currents than by topography, or by vegetation, or by infrastructure," he said.
Earth currents also occur in shallower stratigraphic layers from 5,000-30,000-foot depths.
Earth currents appear to be the strongest determinant as to the physical location of c2g strikes.
The researchers at DML propose it's because the Earth currents are eating away at pipelines and speeding up corrosion.
Also included are several appendices on: vector analysis-definitions and formulas, Bessel functions, parallel-slab equivalent of a slotted coaxial line, earth currents
and distributed impedances, low temperature impedance effects, and a table of physical constants.