A Crustal Study in the Vicinity of the Eskdalemuir Seismological Array Station

Seismic signals from depth charges fired in the North Sea and the Irish Sea in July 1962 and recorded by both the U.K.A.E.A. linear array at Eskdalemuir and by a seismometer in a borehole near Durham have been analysed to give information about the regional crustal structure. Arrivals interpreted as refractions from the Mohorovičić discontinuity have yielded an estimate of 7.99±0.10 km/s for the sub-crustal compressional wave velocity. The data also yields depth contours for the Mohorovičić discontinuity, which has a mean depth in the area of about 25 km. In addition to first arrival data the velocity filtering properties of the array have been used to identify later phases as multiple reflections which are consistent with the above interpretation. Other arrivals, which are predominantly second arrivals, have been interpreted as Pg and yield a crustal compressional wave velocity at 6.12 ± 0.06 km/s.