{{Short description|Vertical growth of solid volcanic lava}}
A '''lava spine''' (or lava spire) is a vertical growth of solid lava that is forced from a volcanic vent. A lava spine can either be formed by viscous lava slowly being pushed out of the vent, or by magma that has solidified within the vent before being pushed out.<ref>Neuendorf, K. K. E., J. P. Mehl Jr., and J. A. Jackson, 2011, Glossary of Geology, 5th edition, revised, American Geological Institute, Alexandria, VA.</ref>
In February 1983, the dome activity of Mount St. Helens culminated in a spine that reached a height of about {{convert|100|ft|m|order=flip}} 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. <ref>{{cite book|last=Sigurdsson|first=H|title=Encyclopedia of Volcanoes|year=2000|publisher=Academic Press|location=San Diego|pages=310–311|author2=B. F. Houghton }}</ref>
== Gallery ==
<gallery class="center"> File:Soufriere Hills Lava Dome Spire1.jpg|A spire of lava on top of the lava dome of Soufrière Hills volcano File:Pelee 1902 6.jpg|A lava spine at the summit of Mount Pelée in 1902 File:Whaleback, Mount St Helens volcanic crater (February 22 2005).jpg|"Whaleback", Mount St. Helens </gallery>
==See also== * Volcanic plug
==References== {{reflist}} {{Commons category|Lava spines}}
{{DEFAULTSORT:Lava Spine}} Category:Volcanic landforms
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