The seismic disturbance on 1986 August 1 near Novaya Zemlya: a source of concern?

On 1986 August 1 a small seismic disturbance occurred to the east of a Soviet nuclear test site at Novaya Zemlya. Reported attempts to identify the nature of the source using only short-period seismological data recorded at regional distances were unsuccessful. However, by using teleseismic P-wave data it is possible to identify the source as an earthquake which occurred within the crust at a depth of 24 km. The source is shown to have a double-couple mechanism with a well-constrained fault-plane solution. The identification as an earthquake is supported by the mb : Ms, evidence.