The First Hundred Years of the Geological Survey of Great Britain

Abstract

The West Nelson earthquake seems to answer the question, sometimes raised, as to whether strong earthquakes are caused only by normal faulting or whether they may result also from thrust faulting. Also, since surveyed points west of the White Creek fault moved upward, west, and north in the same directions, though much less than surveyed points east of the fault, there seems to the reviewer to be no reason to appeal to elastic rebound as a factor of any consequence in producing the fault displacement. The faulting appears to have been, instead, a direct forward shove of an active block which rode obliquely upward above a relatively passive tract on the other side of the fault. Except for steeper angle and greater strike slip, it seems to have occurred much like the familiar thrust faulting experimentally produced in a pressure box. In this mountainous region the earthquake produced innumerable landslips, rock slides, and rock falls, many of which were on a very large scale. These are described in detail in this Bulletin. R. T. C.