Astounding Video of Volcano Shock Wave

[babajees]

This video captures an explosion and shock wave from the Tavurvur volcano in Papua New Guinea, recorded on August 29,2014. The videographer, Phil McNamara, was on vacation at the time, and on a boat as the volcano erupted.

Shock waves are different from sound waves. In this case, as you hear on the video, the volcanic eruption shock wave takes about 13 seconds to reach the camera microphone. Shock waves are strong pressure waves in the air that travel faster than sound, and their speed increases as amplitude is raised. But their intensity actually decreases faster than the intensity of a sound wave.

Thanks to National Geographic!

Fun activity: Assuming shockwave travels at the same speed of sound, what is the distance of the volcano to the guy filming this? (Hint: 13 seconds difference). Anyone?