Seismic analysis of aircraft accidents

Abstract

Seismic records from Finnish and Swedish stations were analyzed for a study of two aircraft accidents in Finland and Sweden. A Hornet F-18 fighter crashed in central Finland, and analysis of recorded impact signals from 7 nearby seismic stations yielded in a crash location only 4 km in error. An estimated magnitude (ML) of 0.5 units gave an impact velocity of 335 m/sec (1200 km/h), which was in excellent agreement with that reported by the Finnish Air Force. A Norwegian Hercules transport plane crashed in foul weather near the summit of Mt. Kebnekaise, NW Sweden. Both seismic and infrasound signals were weak, and in our interpretation, this implied that the Hercules aircraft had a less steep impact angle against the mountain. We also examined seismic analyses of other spectacular air accidents like that of Lockerbie, UK in 1988, and terrorist aircraft attacks on September 11th, 2001 in the USA. Likewise, accidents at sea, such as the sinking of the Russian submarine Kursk in the Barents sea in 2000, and the freighter M/S Rocknes near Bergen in 2004, were recorded and analyzed seismically. In this study, we demonstrated that it was feasible to use seismic registrations to locate impact sites, and to define the exact time of such accidents. Also, negative evidence, i.e., lack of seismic recordings, may provide some information of such accidents and their consequences.