International Data Centre Bulletin Events Triggered by Controlled Underwater Explosions of World War 2 Ordnances.

This paper focuses on events linked to controlled underwater explosions of World War 2 (WW2) ordnances which were included in the Reviewed Event Bulletin (REB). Data used for the study were provided by seismic stations of the International Monitoring System (IMS) in 2020. Examined events were triggered by devices of different charge size and took place in several locations in Europe. There were also other, previously detected WW2 ordnance underwater explosions which could be compared to events in 2020. It is shown that these relatively small underwater explosions listed in the REB, with good coupling to the ground, are located by the IMS network within 20 km from the ground truth. Charge size of explosive material was related to event magnitude. Results were compared to magnitudes published for underwater explosions of larger sizes. The conclusion is that an in-water explosion will result in seismic waves with amplitudes equivalent to the amplitudes of seismic waves from an in-ground explosion with 17.2 times the yield in kT. [ABSTRACT FROM AUTHOR]