Earth Tremor of December 30, 1944, in Britain

Abstract

A CONSIDERABLE, number of personal experiences of the earth tremor have now been received, and it appears that in some places the tremor reached intensity 5 on the modified Mercalli scale (Nature, Jan. 6, p. 15). In Yorkshire, the intensity was greatest in an elongated area near Skipton, and the only damage reported in this county was one chimney which developed a crack, possibly as the result of the shock, and had to be felled. An inquiry has been made concerning possible sounds associated with the tremor, and three definite observations have been made, all supported by independent observation. (1) A rumble: typical observation by Dr. J. R. Ashworth, of Rochdale, who writes, "I heard a very audible rumble accompanying the swaying movement of the house". (2) A sound like a rushing wind, often said to have been followed by a thud, all taking place at the same time as the swaying. (3) No sound: this was the experience of many who felt the tremor and "knew it could not be bombs because there was no sound". So far, no systematic geographical distribution of the observations of the different types is apparent". In one area observations of all three types were reported. Miss E. F. Bellamy, of the University Observatory, Oxford, felt the earth tremor; but the seismograph at the Observatory was not working at the time. The tremor was not recorded on the disk of the Jagger shock recorder belonging to the British Association, then and now working at Comrie. The tentative reading of the record of the tremor obtained by Mr. E. W. Pollard at Binstead, Isle of Wight, shows that it recorded at 00h. 36m. 27s. G.M.T., and Mr. Pollard remarks that the record he obtained was similar to those resulting from "a tank passing at 100 yds., (2) a submarine depth charge at 5 miles, (3) the Burton explosion". No news has yet been received of any possible recordings by seismographs outside the British Isles.