Over the weekend, Santa Maria’s Santiaguito dome complex had a few impressive explosions caused by the collapse of the domes that have been growing on the volcano. One of these explosions was captured in great detail by INSIVUMEH, the volcano monitoring agency of Guatemala. I’ve annotated the image to show all the pieces of such a vulcanian eruption. The plume of the explosion is formed by an explosion from the dome as it collapses, releasing pressure on the magma underneath it. This drop in pressure causes bubbles to form and bam! An explosion happens.
This explosion causes material to shoot upwards in the gas thrust portion of the plume. Now, volcanic plumes can be of a lot of different heights, from a 100 meters to over 50 kilometers. So why are they so different?
UPDATE August 22, 2016: I had some discussions with Rudiger Escobar Wolf, a volcanology graduate student ...
