The distribution of intensity of the Bihar-Nepal earthquake of 15 January 1934 and bounds on the extent of the rupture zone

Abstract

We have recompiled the descriptions of damage and destruction caused by the 15 January 1934 Bihar-Nepal earthquake, given by both Dunn et al. (1939) and by Major General Brahma Sumsher J. B. Rana (1935), to infer bounds on the dimensions of the rupture zone of that earthquake. The distribution of damage in northern India was very uneven, and much of that destruction was closely associated with slumping, fissuring, and tilting of the ground. The absence of any preferred orientation of the fissures and the prevalence of sand and water issued from fissures suggest that this disruption of  the  earth's  surface  was  limited  to  surficial  layers  and not to faulting of the  basement  beneath  that  area.  Thus  much  of  the  damage  in  northern India, perhaps the majority, was  not  due to  shaking  or  to  high  accelerations  of  the  ground, but rather to disruption ot the earth's surficial layers. Except for three short trips to parts of Nepal by.  J.  B.  Auden, Dunn and his colleagues has access to little information from Nepal, and their descriptions of the effects of the earthquake in Nepal were brief. Rana, however, made extensive compilations both of destroyed buildings and of casualties in various districts and towns in Nepal, and it appears that the greatest destruction lay in the parts of Nepal that Auden did not visit. Where Rana and Auden gave independent assessments of the damage, their reports agreed sufficiently well, that the particularly heavy toll reported to have been taken by the earthquake in the mountainous terrain of east-central Nepal probably is not an exaggeration.  This area, in fact, includes the epicenter of the earthquake recalculated from arrival times of P waves.