(By C. Tienrey, 2010)
Lava domes, which may also be referred to as volcanic domes, are common features in volcanic regions throughout the world. Lava domes can come in many shapes and sizes, and while they may not be quite as spectacular as their explosive or flowing counterparts, they are often still an awe inspiring sight to see. The purpose of this page is to provide a brief introduction to lava domes, which will by no means be entirely comprehensive. In fact, even today, there is still much unknown about lava domes and what they can potentially reveal about volcanic systems.
Lava domes are formed by viscous magma being erupted effusively onto the surface and then piling up around the vent. Like lava flows, they typically do not have enough gas or pressure to erupt explosively, although they may sometimes be preceded or followed by explosive activity. However, unlike lava flows, the lava that forms domes is often to thick and sticky to flow very far, and thus instead pile up thick and high around the vent.
Photo credit: USGS. 1984 USGS picture of the growing Mount St. Helens Lava dome. This lava dome started developing shortly after the iconic May, 18th 1980 eruption and dome growth continued until 1986.
Photo credit: Casey Tierney. 2009 picture of Chillahuita lava dome found in the Andes Mountains of South America. Note the large difference in appearance (and size!) as compared to the 1980’s Mount St. Helens Lava dome.
References and Additional Resources
USGS website on lava domes. http://vulcan.wr.usgs.gov/Glossary/Domes/description_lava_dome.html
Francis, P., Oppenheimer, C. 2004. Volcanoes. 2nd Ed. Oxford University Press, New York.
Fink J. H., Anderson, S.W. 2000. Lava domes and Coulees, In: Sigurdsson et al., eds., Encyclopedia of Volcanoes, Academic Press, 307-319.
Blake, S., 1989, Viscoplastic models of lava domes, IAVCEI Proceddings in Volcanology, Vol.2. Lava flowsand domes, Springer Verlag, Heidelberg, 88-126.
de Silva, S.L., Self, S., Francis, P.W., Drake, R.E., Ramirez, C., 1994. Effusive silicic volcanism in the Central Andes: The Chao dacite and other young lavas of the Altiplano-Puna Volcanic Complex. Journal of Geophysical Research, 99, 17,805-17,825.