This, is all speculation based purely on what little is known about Nabro in Africa.
Eruption cessation source:
First a little short back story. Krakatoa. She erupted from one of her 3 major peaks, initially a violent explosive eruption with large flows. Then
suddenly she went quiet. A cork of cooled rock sealed her now disturbed magma chamber off... later, all three peaks blew in one massive eruption. This
is a repeating process it seems, Krakatoa apparently has a history of explosive eruptions of varying sizes. The primary factor in Krakatoa's eruption
was an initial basalt magma, then rhyolite magma for the final explosion.
Now back to Nabro. Nabro is part of a caldera system like Krakatoa was...with the same kind of magma...
Basalt, trachyte and rhyolite are among the rock types which Nabro has produced as lava flows and pyroclastics.
From Wiki, sourced from www.volcano.si.edu...
While we don't know the specifics, like I said, this is speculation based on information I can find...there is this.
The other day, this was Nabro.
Today it has stopped erupting suddenly...like Krakatoa did.
So we have established, A: Similar magma types, B: Both erupted violently, then went quiet before the main event (for Krakatoa so far, at least.)
EDIT: Adding from one of my reply posts for clarification purposes for future readers.
In reply to Krakatoa and Nabro being Rift vs Subduction zoned volcanoes and thus different formation types.
Clarification: While the volcanoes formed under different circumstances, we know both have similar magma, both are explosive, and both are large. The
Nabro eruption shows large quantities of water vapor in it's plume. I think, while formation is different, the end product might be similar.
Now the final thing.
This is Nabro in January 2011.
If you go to Google Earth you can see ALL the volcanoes in this system have large calderas from major, explosive eruptions. The current vent that we
just saw actively, did not produce such a crator. It erupted and has now, seemingly, plugged itself.
With a disturbed magma chamber, and a plugged vent - if there is still pressure in the chamber, then its possible we will see another explosive
eruption... and based only
on the geological sat photos, it seems that this volcano has had major eruptions in the past.
I'm not ringing a bell here, there is no need for panic. I am posting this purely as a geological interest, and I want
other people to give
me their own opinions. A geologist friend said, without field data and historic eruption information he can't tell me one way or the other. So I
decided to simply share this.
Again, I am posting this as a geology intrigue, not as "DOOMSDAY OMG" post. This is simply an interest event and I feel we seriously need to study the
situation there. Without more information we will not know. Simple as that.
edit on 30-6-2011 by Foxe because: (no reason
edit on 30-6-2011 by Foxe because: corrections
edit on 30-6-2011 by Foxe because: Adding content