Inside an Eruption
Magma and gas rise from below Earth’s surface.
Rising gases push on the sealed vent.
Gases explode, breaking the seal.
Ash and gas shoot upward.
Lava flows across the land.
The explosion ends. The seal closes again.
magma and gas
How It Works
The plan was to hike to the top of Santa María. Here, the team could see the lava domes from above. Before an eruption, the vent of the dome is sealed.
Magma and gases are trapped. Pressure builds. The seal breaks. Magma comes out as lava.