Atmospheric focusing
Atmospheric focusing is a phenomenon occurring when a large shock wave is produced in the atmosphere, as in a nuclear explosion or large extraterrestrial object impact. The shock wave is refracted horizontally by density variations in the atmosphere so that it can have impacts in localized areas much further away than the theoretical extent of its blast effect. In large bombs, some effects may thus be found hundreds of kilometers from the blast site.
This effect operates similarly to the patterns made by sunlight on the bottom of a pool, the difference is that the light is bent at the contact point with the water while the shock wave is distorted by density variations.
