Eruption of Mount St Helens in autumn 2004,producing a plume of volcanic ash and steam (centre). The orange-pink glow is due to the setting sun. Mount St Helens,in Washington State,USA,is famous for its 1980 eruption,one of the largest in the recent history of the USA. That eruption destroyed the top of the volcano,leaving a large summit caldera,the walls of which are seen at right and in the background. Since the 1980 eruption,new volcanic activity has formed a lava dome inside the summit caldera. The most recent activity began on 1 October 2004,and the volcano has been continuously active since then,with the lava dome still growing in size as of February 2007 |