When Mount St Helens exploded into life in 1980, it was one of the greatest ever recorded eruptions in North America. Superheated ash, gas and lava devastated the surrounding area and claimed many lives.

Since then scientists have been closely monitoring activity around the volcano, waiting for disaster to strike again. In September 2004, the mountain began to rumble into life once more, leading to eruptions that scattered ash for miles around the Cascades Range.

Lava has been escaping inside the crater and the dome it has formed is still growing. The volcano has been put on Alert Level 2, which means there could be further eruptions. So, is Mount St Helens about to blow?