[billsmithaustin]

Just playing back what you said because it's surprising. You're saying that explosion was not caused by water that was superheated by the supervolcano below the greater Yellowstone Caldera? It was heated by some other source?

Interested because I was there a few weeks ago.

[mapt]

A defined hydrothermal basin like this is heated by a very local pocket of magma or more properly magma-that-has-mostly-solidified-into-hot-rock, only a kilometer or so deep in this case, that has leaked up from multiple layers of deeper basins creeping up through faultlines, and which is being gradually cooled by water seepage in a dynamically stable way. Depending on the area, there may or may not be an intermediary superheated brine functioning as a heat transport mechanism, per https://en.wikipedia.org/wiki/Geothermal_areas_of_Yellowston...

Local explosions like this are not very indicative of movements in the county-sized reservoir of magma ten times deeper down that underlies the entire caldera.

Local hydrothermal basin, upper magma chamber, lower magma chamber, mantle plume: https://www.yellowstonepark.com/news/supervolcano-magma-cham...