<http://schema.org/about>
"When a volcano erupts explosively, molten rock bubbles upward at the speed of sound, forming glass-like rocks that shoot out of the earth as fast as a speeding"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/wilderness-resources/stories/why-all-volcanic-eruptions-are-not-created-equal>