Asteroid impacts or nuclear explosions in the Black Sea may lead to poisoning of the coastal population

Abstract

The hydrogen sulphide rich waters of the Black Sea pose a potential danger for the surrounding land regions. The impact of an asteroid exceeding tens of metres in size or a very large nuclear explosion may cause a catastrophic poisonous gas release in the atmosphere. A 250 m size asteroid impacting the southern regions of the Black Sea is treated here as an example. Wind speed and direction play an important role in H₂S cloud dynamics. At 10 m/s wind speed, the cloud margins may be seen at about 185 km from impact location in about 3 hours. The influence of the impact position on the distance travelled by hydrogen sulphide clouds is rather weak, as the seawater depth does not change significantly. The land surface area covered by the H₂S cloud during the run‐in ranges between about 1400 km² and 2100 km² and up to 120,000 people may be affected. These evaluations do not include the population of the towns on or near the seashore.

Keywords:

• Asteroid impact
• Nuclear explosion
• Black Sea
• Hydrogen sulphide
• Poisonous gas release
• Down‐wind dispersion

Acknowledgments

The author thanks Prof. R. D. Schuiling (Utrecht University), Prof. E. Pelinovsky (Institute of Applied Physics, Nizhny Novgorod), Dr D. Isvoranu (Polytechnic University of Bucharest) and Mr R. B. Cathcart (Geographos, Glendale, CA) for stimulating discussions. The connection between asteroid impacts and nuclear explosions was suggested by Dr Michael Brett‐Crowther to whom the author expresses his gratitude.