The sound of summer: rockfall inside the crater of Mount St. Helens.
Detailed Description
In summer, the crater of Mount St. Helens is filled with a near constant sound of rockfall from the steep 600 m high (about 2000 feet) crater walls. The falling rock kicks up ash and dust (pulverized rock) as it tumbles onto the crater floor. View of east crater wall.
Sources/Usage
Public Domain.