In 2014, scientists blasted Mount St. Helens, one of America's most closely watched volcanoes, with 23 explosions, revealing a vast magma system underground

In 2014, scientists detonated 23 controlled explosions around Mount St. Helens, one of America's most closely watched volcanoes, using thousands of seismic instruments to map its hidden interior. The experiment revealed evidence of a complex magma-storage system buried deep beneath the volcano, including a major reservoir about 4 to 15 kilometres underground.