Magnetovariational and Magnetotelluric Investigations in S. Scotland
V.R.S. Hutton and A.G. Jones
A two-dimensional array of 20 Gough-Reitzel magnetometers was operated over
S. Scotland in 1973 and in 1974-5 magnetotelluric and magnetovariational observations
in the period range 10-10,000 S were made in the same region. In this paper,
the analyses of the magnetic data from both studies are presented in the form of
induction vectors and hypothetical event contours. They suggest that the lateral
variations in electrical conductivity structure associated with the Eskdalemuir anomaly
are more complex than suggested by earlier studies. A marked discontinuity in electrical
structure is apparent in a narrow belt parallel to and south of the S. Uplands fault.
This belt is associated with a major gravity anomaly and with steep gradients in the
seismic profile at crustal depths. Another discontinuity is indicated near the Northumberland
Basin. Representative examples of the magnetotelluric analysis and of one-dimensional
Monte Carlo inversion of the M-T data are presented for the three regions
separated by these discontinuities. They show that the conducting zone associated with
the Eskdalemuir anomaly is at a depth greater than 24 km, while on either side of this
region, there are good conductors within crustal depths.
In: Electromagnetic Induction in the Earth and Moon,
edited by U. Schmucker.
AEPS-9, Centr. Acad. Publ. Japan, Tokio and D. Reidel Publ. Co., Dordrecht,
Suppl. Issue of
Journal of Geomagnetism and Geoelectricity, 141-150.
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Alan G Jones / 28 February 2010 /