Electrical Resistivity of the Crust and Upper Mantle at Eskdalemuir, South Scotland

Abstract

THE oscillations in telluric field in magnetic north–south and east–west directions were recorded at Eskdalemuir (55° 19′ N., 3° 14′ W.), South Scotland, over three weeks in December 1963. The electrodes consisted of 2 ft.², 0.25-in. steel plates buried 2,000 ft. apart. The recording and the La Cour magnetograms made at the observatory yielded the data for this magnetotelluric examination. The period of recorded oscillations ranged from 20 sec to 100 min. The records were visually analysed and only the pulsations with good sinusoidal shapes and having no noticeable vertical component were considered. By the courtesy of G.P.O. Engineering Department, magnetotelluric data were also collected on the cables across the Irish Sea. This was, however, considerably affected at the lower end of the spectrum by near surface features and will only be referred to here. A paper covering the details of this investigation is under preparation, and will be published elsewhere.