HELICOPTER CRASH ON THE SPITSBERGEN ARCHIPELAGO:
INFRASOUND AND SEISMIC SIGNALS DECRYPTION

1 Federal Research Center «Geophysical Survey of the Russian Academy of Sciences», Obninsk, Russia

2 Kola Branch of the Federal Research Center «Geophysical Survey of the Russian Academy of Sciences», Apatity, Russia

Abstract. The Mi-8 helicopter has crashed near the Russian settlement of Barentsburg on October 26, 2017. The seismo-acoustic array «Barentsburg», which is located at a distance of 2.5 km from the crash site, has registered the accident. The array consists of 3 low-frequency microphones and a broadband seismic 3-component station.

The paper provides a detailed analysis of the obtained seismic and low-frequency infrasonic records of signals, caused by the crash. Two types of signals were detected in seismic records: a wave caused by the helicopter fall into water and propagated through the earth, and an air wave also generated by the crash but propagated through the atmosphere. The wave of the second type was also recorded by low-frequency microphones of the infrasonic microarray. The method of the source coordinate determination by joint analysis of acoustic and seismic signals is described. The difference in arrival times of seismic and acoustic waves was used to determine the distance to the source, and the back azimuth was calculated using the differences in the arrival times of the acoustic wave to the spaced microphones of the infrasonic microarray.

The recordings of the acoustic signals associated with the operation of the helicopter rotor before the crash and at the moment of impact with water are considered. Detailed analysis of the frequency and amplitude composition of the seismic and infrasound signals allowed not only to determine the exact place and time of the helicopter crash, but also to estimate the trajectory of its movement before the fall, as well as to restore some details of the accident.

Keywords: infrasonic signals, seismic signals, seismo-acoustic array, seismo-acoustic locating, helicopter crush, Spitsbergen.

About the authors

VINOGRADOV Yury A. – Cand. Sci. (Tech.), Director, Federal Research Center «Geophysical Survey of the Russian Academy of Sciences». Obninsk, Russia. E-mail: yvin@gsras.ru

FEDOROV Andrey V. − Cand. Sci. (Phys. and Math.), Director, Kola Branch of the Federal Research Center «Geophysical Survey of the Russian Academy of Sciences». Apatity, Russia. E-mail: Afedorov@krsc.ru

Cite this article as: Vinogradov Yu.A., Fedorov A.V. Helicopter crash on the Spitsbergen Archipelago: Infrasound and seismic signals decryption, Geofizicheskie Protsessy i Biosfera (Geophysical Processes and Biosphere), 2019, vol. 18, no. 1, pp. 111–117 (in Russian). https://doi.org/10.21455/gpb2019.1-10

English version: Izvestiya, Atmospheric and Oceanic Physics, 2019, vol. 55, iss. 7. ISSN: 0001-4338 (Print), 1555-628X (Online). URL: https://link.springer.com/journal/volumesAndIssues/11485