|Exploding lava bubble at Mount Etna|
Photo copyrighted by Tom Pfeiffer
from Volcano Discovery
Here, the photographer captured the source of one such boom, a lava bubble (what is the scale??) bursting from the lava lake at Mount Etna.
In text accompanying the photo at the left, the photographer reported that "a loud detonation and a strong shock wave that felt like a punch into the stomach when observed from 300 meters distance, accompanies these bursts. Even at 10 km distance, windows rattle."
Audible booms or atmospheric shock waves are produced when something pushes suddenly on the atmosphere. This is most easily illustrated with a one-dimensional experiment called a "shock tube." These were developed to explore the effects of bombs on the atmosphere, but have been widely used to investigate basic science problems such as chemical kinetics, and basic properties of gases as a function of pressure and temperature.
|Schematic of a shock tube experiment.|
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