Eventually the cone became so steep that the flanks collapsed under their own weight. The collapsing cinders came to rest when the sides reached just the right steepness to keep them stable. Mauna Kea Volcano. Photo by J.P. Lockwood. Every pile of loose particles has a unique angle of repose, depending upon the material it's made from.
Cinder cones are commonly very symmetrical.
The birth of this small cinder cone is only part of it's intriguing story. Click here to continue. This site is a cooperative endeavor of the US Geological Survey Western Earth Surface Processes Team and the National Park Service .