#Marapi #volcano: damn. :( Deep condolences to the people who died in today’s unexpected eruption (its largest in its history, according to #GeologyHub).

While many eruptions can be predicted based on specific types of earthquakes and gas emissions, sometimes magma and underground water reservoirs meet, which makes the water flash to steam and causes an explosion, which triggers an eruption. These are called #phreatic eruptions, and they just flat-out cannot be predicted. :(

I love a good #maar #volcano sequence.

A few shots of our work at the Estrada rhyolitic maar, one of the >10 #volcanic craters around the city of Kamembarhu, Kuanhasï juata (Mexico). These spectacular layers of pulverized bedrock and ashfall--exposed at a quarry--are the result of explosions caused by ascending #magma intruding into near-surface water reservoirs (in this case, shallow lakes). We call these types of events #phreatic eruptions. Note excavator for scale.