Lava spine

A lava spine at the summit of Mount Pelée in 1902

A lava spine is a vertically growing monolith of viscous lava that is slowly forced from a volcanic vent, such as those growing on a lava dome (Bates & Jackson, 1987). It may also be considered a kind of dome called a spiny dome (Fink & Anderson, 2000).

In February 1983, the dome activity of Mount St. Helens culminated in a spine that reached a height of about 30 metres (100 ft) before collapsing after two weeks, but in 2005 another lava spine (called the Whaleback) lasted until it collapsed in July 2005. In November 2005, a new spine, called "the slab" grew continuously until late 2006, though it continually collapsed under its own weight; the growth finally stopped in January 2008, when Mount St. Helens' eruption ended. Another example is a spine that appeared on the lava dome of the Soufrière Hills Volcano in Montserrat prior to the volcano's eruption in 1997.

A diatreme may also be referred to as a lava spine, such as the example of Mount Pelee in 1902.[1][2][3]

A spire of lava on top of the lava dome of Soufrière Hills volcano


  1. ^ Bates, Robert L. (1987). Jackson, Julia A. (ed.). Glossary of Geology (3rd ed.).
  2. ^ Sigurdsson, H; B. F. Houghton (2000). Encyclopedia of Volcanoes. San Diego: Academic Press. pp. 310–311.
  3. ^ "History- Mt. St. Helens". Retrieved October 2, 2011.