Wikipedia:POTD column/April 12, 2006



Pu'u 'O'o is a classic cinder-and-spatter volcanic cone on Kilauea, Hawaii. Expanding gases in the lava fountain tears the liquid rock into irregular globs that fall back to earth, forming a heap around the vent. The still partly liquid rock splashing down and over the sides of the developing mound is called spatter.

Photo credit: G.E. Ulrich of the United States Geological Survey Archive - Nominate new image