Michigan Tech's Volcanoes Page provides information about volcanoes. Info about current global volcanic activity, research in remote sensing of volcanoes and their eruptive products, hazard mitigation, etc. This cross-section shows the parts of a volcano. A conduit feeds magma to the surface. Near the surface, the gas expands and fragments the lava into ash.
Some magma passes through dikes to feed vents.
Some magma intrudes parallel to layers to make sills. Messages posted directly by observers have not been edited or confirmed. Releases describing the current state of volcanic activity along the Aleutian arc. You have been given the opportunity of a lifetime. The USGS Cascade Volcano Observatory in Vancouver, Washington would like you to study Mt. Rainier.