Magma Crystallizes Hotter
New trigger found for volcanic eruptions - the more magma crystallizes, the hotter it gets. Meanwhile, Mt. St. Helens spews away. For great background information on Washington State geology, consider Roadside Geology of Washington.
Much still unknown in Geology, with major changes (and arguments over) in thinking since the beginning of the science. Great Geological Controversies provides an excellent background on the various controversies.