In 2014, scientists set off 23 blasts to map magma beneath Mount St. Helens

Mount St. Helens is one of the most closely studied volcanoes in the United States, but scientists still cannot directly see the complex system of magma and rock hidden beneath it. In 2014, researchers launched an ambitious experiment to change that. According to the Imaging Magma Under St. Helens (iMUSH) project, a field team used 23 controlled explosions and a remarkably dense network of seismic instruments to send waves through the ground and map what lay beneath the volcano. The results, combined with later seismic studies, helped identify an upper-crustal magma-storage zone roughly 4 to 15 kilometres beneath the volcano.An experiment beneath a volcanoThe 2014 project was part of iMUSH, an interdisciplinary effort designed to investigate the magmatic plumbing system beneath Mount St. Helens. Rather than waiting for natural earthquakes to provide the necessary seismic signals, researchers deliberately generated their own waves.