In February 1983, the dome activity of Mount St. Helens culminated in a spine that reached a height of about 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.