(04-22-2025, 12:30 AM)kalianna Wrote: So whatʻs your guess? A big blow or moving toward pau for now?
My thoughts.. although, as I said I am better at observing what happens than figuring out what the future holds, I still have them.. and they morph endlessly.. with new information.. new behavior.. the new compared to the old.. and you know, I think that’s the best part of the whole thing.. the wonder of it all.
Before this last event we had a simple plot.. the phases started, got bigger, got smaller.. and it was easy to imagine a linear trajectory to some sort of change.. I pointed out the history of high fountains followed by lakes.. but this new phase took longer before it started, and it was strikingly how much more efficient the vents were, how more voluminous the outflow although for a fairly short duration..
The most striking change, to me, is that instead of the tilt dropping more than the preceding inflation, the eruption stopped before the amount accumulated before the eruption was expended. In other words maybe there’s a net gain to the mountain’s magma body rather than a loss. It will be interesting to see if the same holds through the next eruptive phases.
What I sense is the space the magma is accumulating in before it erupts is in a constant state of change.. and with the last two phases we’ve seen that space change considerably. At least that’s the first thing that comes to mind..
Keep in mind it takes a particular set of circumstances for a high fountain eruption to occur. Some balance between the size and shape and depth of the space the magma body accumulates in prior to erupting, and the resistance it has to overcome to erupt. A molten environment where the containing rock structure itself is made of the same material so there is a constant change. Thermal melting and freezing of rock due to the ebb and flow of the magma that alone would, over time change the balance of things. Add to that shifts in blocks of rock, that we see as earthquakes, keeping in mind the magma is ascending through a massive pile of ruble left from the collapse of ’18, and the ebb and the flow of the melt itself, as it melts its host and finds new crevices to fill, things are constantly evolving.
There is a bit of a discussion of the perimeters involved in a gas driven high fountain eruption in the first page of Maggie Mangan's Vesiculation of basaltic magma during eruption.. which is shared as a sample here...
https://pubs.geoscienceworld.org/gsa/geo...g-eruption
In the bigger picture.. the volcano is reinflating after the 2018 drawdown.. and as we’ve seen with forays into the Southwest and East Rift Zones it’s reoccupying all the voids it encounters along the way. And, again my sense is, magma has found another void space to fill, somewhere laterally in the summit itself so as to still be seen by the broader GPS network as a continuing inflation, but it’s diverting magma that would otherwise have erupted through the active vent earlier in the cycle. And still, the new space was filled in short order and the madam returned to the good old days of rock n’ roll.. it is Merrie Monarch week, after all. Right?