Still working on an The Chaiten Volcano in Chile is erupting, first time in at least 2000 years, more likely the last eruption was about 10,000 years ago.
The eruption is intensifying and local towns are being evacuated
GDACS has issued a Green Alert
International Volcano Research Centre has more info
Ok, nice volcano, low population density, and Chilean navy seems to have the evacuations under control. Currently spouting ash.
The interesting thing is that the last eruption was a Caldera forming explosion of unknown strength, but indirect evidence puts it on the large eruption list - holocene era eruptions with Volcanic Explosive Index of 4 or larger (estimated) - Mt St Helens in 1980 was a 5, Pinatubo in 1991 was a 6.
So the mountain can blow - doesn't mean it will this time, most eruptions are not big, and even after a long period of dormancy the current eruption may just be a burp.
But it is worth keeping an eye on.
A VEI 5 or 6 event would start affecting hemispheric climate on a few year time scale - predominantly regional cooling. Could be interesting for Australia and sub-Saharan Africa, and not necessarily in a bad way, depending on a lot of things...
Sounds like the last eruption produced 0.1-1 cubic kilometers of tephra - see Naranjo and Stern 2004 - for comparison, the Mt St Helens 1980 eruption was just over a cubic km.
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Our problems are nothing like Chile's, but Halema'uma'u Crater within Kilauea on our Big Island has recently began erupting. For several days the crater rim was evacuated, and the eruption continues to leak "Vog" all over Hawaii.
Posted by: Louise | May 7, 2008 11:28 PM