Physical volcanology of domes

Volcanic domes are very common in stratovolcanoes (i.e., Mt. St. Helens) or around caldera complexes (Glass Mtn, Long Valley caldera). By themselves, however, in small fields, they are reasonably rare in present active systems. This should not imply, however, that they have been rare throughout geologic time. Because they are not present in active systems, they can be thought of as the "oft-forgotten cousins" of the volcano family. What better reason to study them? My perspective is that it is a mistake to assume that domes, whether in stratovolcanoes, calderas, or by themselves, will act the same, and erupt in the same way.

The evolution of the domes in the mid-Tertiary field was varied. Some of the domes had a history of collapse, generating moderate-volume block-and-ash flows. Some exploded, generating generally smaller pyroclastic flows. Some simply grew endogenously (from within), leaving dense lava flows at the surface. My goal in physical volcanology is to see what factors control these various modes of growth and destruction of domes. I have suggested that size and proximity to other domes is a factor (see pub list), and it has been suggested to me that magma production rate is the key. In any event, it seems best to map as many of the domes as possible, since their composition is within a narrow range, and see what parameters fall out. This could help in prediction when dome fields are recognized. An application of these ideas may turn up in some interesting work in Mexico, so click this link if that sounds interesting.

Riggs, N.R., Tillinghast, S.F, and Ash, N.A., 1998, Dome growth, pyroclastic volcanism, and destruction in an isolated-dome field, central Arizona, USA: EOS Trans., AGU vol. 79, p. 1000.