On my random speculations

Chaiten Ash

Before we get too far, I wanted to make sure that folks understand that I'm just making educated conjectures on the nature of the eruptions I read about and by no means do I have any extra insight over those scientists on the ground at the eruption. I have a very limited set of data to examine - whatever the media reports - so I am just speculating based on what I know about the eruption style, volcano in question and whatever other variables might come into play. So, please, don't think that I know exactly what is going on or what will happen better than the scientists tackling the volcano firsthand.

That being said, I might not be a big fan of Donald Rumsfeld, but he does divide things up nicely when it comes to assessing a situation, so here we go.

For Volcan Chaiten:

Known knowns: The volcano has been erupting for the past week; large ash column up to possibly as high as 90,000 feet (!); thick ash deposits (>30 cm) out 10s of km from the vent; potentially lava extrusion at the vent; no pyroclastic flows, no lahars (so far); two discrete vents have coalesced into one vent; upwards of 2 cubic kilometers of erupted material (thus far); last known eruption at Chaiten was 7450 BC, or roughly 9,500 years ago.

Unknown knowns: How long will the eruption last?; how long until the supply rate of pyroclastic material from the vent drops below the rate needed to keep the ash column aloft?; when the ash column collapses, how big will the pyroclastic flows be?; will lahars begin to be generated?; will the volcanic edifice collapse due to the eruption? if so, will there be pyroclastic flows generated by the collapse and/or ring vents forming?; is this the main eruption or will things get bigger? how much lava will be extruded at the main vents? will more vents open?; how long until people can get near the vent to see what has occured firsthand?

Unknown unknowns: Well, I can't really speculate of these, now can I?

At least we know that Chaiten spared the berry crops!

More like this

Another day, another development at Chaiten. Military stationed near the volcano helping with evacuations reported "booming noises" and saw incandescent blocks getting hurled from the vent area. This suggests that lava is at the surface and potentially that the edifice itself is beginning to…
Image courtesy of Calvin Hall. Taken 3/28/2009 during an eruption at 10:59 AM3:28 PM. UPDATE 4/2/2009 at 11 AM Pacific: I'm moving this up from the comments, but Eruptions reader Doug Cole pointed out (and I have no idea how I missed this) that Redoubt has a new webcam! This one is at the DFR…
This marks a full week of eruption at Chaiten and the volcano shows no signs of abating. You have to feel for Luis Lara. He is apparently the pointman for the SERNAGEOMIN in regards to this eruption and really, I think its anybody's guess what might happen next. Heck, we haven't seen many…
UPDATE 2/19/2009 9:45 AM: Well, it seems that my hunch was at least partially right. Reuters (and Paula Narvaez, special envoy to the Chilean president) is calling the eruption as result of "what appeared to be a partial collapse of its cone." So, we might have seen the oversteepening of the dome…