ON THE BURTON-ON-TRENT EXPLOSION OF 1944 NOVEMBER 27

Abstract

Seismic waves from the Burton-on-Trent explosion of 1944 November 27 were recorded at four British and six continental stations. The five observations of Pn suggest that the times of Pn about distance 8° for a surface focus are 3s.9±1s.3 shorter than those given in my 1940 table. The anomaly cannot be explained by any permissible reduction of the thicknesses of the upper layers. It seems just possible that it might be explained by an increase of the velocity of Pn at short distances, but further investigation is needed before this explanation can be adopted. Sg was satisfactorily recorded, and it is likely that the low velocity of Sg found in the Oppau explosion was not due to misidentification, but to ordinary errors of observation. The energy of the explosion and that of the ground movement were in about the same ratio as in the Oppau explosion.