Geophysical Abstracts 152 January-March 1953

24 GEOPHYSICAL ABSTRACTS 152, JANUARY-MARCH 1953
bltie line acre-magnetic maps which show by contour lines the total magnetic
intensity at about 1,000 ft above ground level: G. P. 114, Rosaire, L'lslet, and
Montmagny Counties; G. P. 115, St. Magloire, Moiitmagny, Bellechasse, and
Dorchester Counties. M. C. R.
ELECTRICITY
GENERAL AND THEORETICAL STUDIES
14249. Tikhonov, A. N., and Lipskaya, N. V. O variatsiyakh zemnogo elek-
tricheskogo polya [On the variations of the terrestrial electric field]:
Akad. Nauk SSSR Doklady, torn 87, no. 4, p. 547-550, 1952.
Relations between the components of the geomagnetic field and those of the
geoelectric field are derived starting from the fundamental Maxwell equations
connecting vectors of the terrestrial electromagnetic field. These equations con­
tain the velocity of terrestrial rotation at the point of observation, and char­
acteristics of the upper formations, their electric conductivity, and the thickness
of this formation, resting, as assumed by the authors, on an ideally conductive
medium. S. T. V.
Rlkitake, Tsuneji. Electrical conductivity and temperature in the earth. See
Abstract 14353
14250. Wait, James R. The electric fields of a long current-carrying wire on
a stratified earth: Jour. Geophys. Research, v. 57, no. 4, p. 481-485,
1952.
A solution is obtained for the electrical field parallel to an infinite current-
carrying wire over a flat earth represented as a 2-layer structure with a rela­
tively high conducting zone at depth. The solution shows the field is appre­
ciably influenced by the presence of a conducting zone at a depth of 500 m for
a frequency of 500 cycles per second. Such zones should therefore be detectable
by a geophysical exploration technique involving measurement of electrical
field components in phase and in quadrature with the source current in the
primary wire. M. C. R.
14251. Wait, James R. Electromagnetic fields of current-carrying wires in a
conducting medium: Canadian Jour. Physics v. 30, no. 5, p. 512-^523,
1952.
Electromagnetic field components of linear current-carrying wires in a con­
ducting medium are investigated. It is hoped the results will be applicable to
electrical well-logging methods. Formulas are derived for the field components
for a linear wire carrying a sinusoidal current embedded in an infinite homo­
geneous and conducting medium. It is shown that the cylindrical insulated
covering for the wire does not alter the field appreciably.
Calculations are made for an insulated vertical current-carrying wire placed
in a horizontal conducting slab where the lower region is highly conducting
and where the lower layer is a good insulator. Mutual impedance is deter­
mined between a vertical grounded wire in the slab and a horizontal wire ele­
ment of the same length on the surface of the slab. Graphs are constructed
with impedance plotted against frequency for a homogeneous conducting half
space and also for the two additional cases where the slab is terminated by a
high conducting and a highly insulating lower medium. /. Z.