Seismological Data from India

Abstract

MUCH useful seismological data is contained in the Seismological Bulletin of April, May and June, 1939, recently published by the Government of India Meteorological Department. It contains interpretations of the seismograms obtained at seven observatories in India and Ceylon together with macroseismic data supplied by voluntary observers in nine regions. About sixty earthquakes were recorded at each of the observatories for the three months, though only nineteen were registered at the Haig Observatory at Dehra Dun. This is not considered significant on account of the types of instruments in use at the stations, a full list of which is given. The region near Shillong appears to have experienced more earthquakes than any other during the period, having had five on four separate days. The most intense activity, however, seems to have been near Silchar on May 27, 1939, when eight shocks were felt attaining a maximum intensity seven on the Rossi-Forel scale (overturning of loose objects; fall of plaster; general fright, though no damage to property). The total duration of shaking was approximately 3½ minutes.