Alert level raised at Anak Krakatau


Anak Krakatau in Indonesia.

Eruptive activity is definitely on the uptick at Anak Krakatau. The Jakarta Globe is reporting that the volcano is "spewing molten lava 1000 meters in the air". I'm not entirely sure if that is accurate or that the volcano is throwing volcanic bombs or tephra that high. The head of the Volcanology and Geological Disaster Mitigation Center in Indonesia, merely referred to as Surono in the article (are we playing Brazilian soccer?), says that the volcano is "a high threat because the eruptions have started spreading." Again, I'm not too sure what that means, whether this implies that they see multiple vents or that the eruption is just getting large in magnitude. In any case, it still seems pretty impressive and potentially hazardous. Officials at the Krakatau observatory have created a 3-km exclusion zone around volcano. This might suggest that the local people were right to be concerned about the level of activity at Anak Krakatau over the past month. It is also hard to tell from this article whether the higher alert level at Anak Krakatau is higher than the Alert 3 that was mentioned in this week's SI/USGS Report.

Note: There is supposedly an Anak Krakatau webcam, but I have yet to get it to offer me anything but a connection timeout. Anybody else know of a webcam for this volcano?

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Bruce - Wow, that is a great site for Indonesian volcanoes, especially the impressively-long sidebar with all the volcanoes listed. Thanks for the link!

"are we playing Brazilian soccer?"
An ineresting bit of cultural infor is that many Indonesian's only use a single name.

Although Krakatau has not had a long enough repose to have another caldera forming event, the resuregence or growth of Anak Krakatau is certainly impressive.

So, we are playing Brazilian soccer!

I'd agree, I don't think we're looking at anything to the scale of the 1883 eruption, but it could be impressive nevertheless.

Hi Erik, I just wanted to use your comments column to say thanks to Bruce S. for that Indonesian link. It's amazing, the wonderful sites out there that one is completely unaware of until someone points them out! - Ralph

The entire VSI site has been timing out(at least through my ISP)for months and months; and thanks to Bruce for the link!

On a prior thread someone posted some information about Krakatau writing: âadding that the eruptions could be heard in Pandeglang, a town some 100 kilometers inlandâ.

I suppose any volcano that is that noisy should be given more than a 1 kilometer exclusion zone. Too me the noise indicates intense pressure blasting out from deep down.

By Thomas Donlon (not verified) on 07 May 2009 #permalink

how big could the Eruptive be ???

could it be a VI 6 or 7???

David - My guess is any potential eruption right now for Anak Krakatau isn't going to be anywhere near VEI 6-7. More likely it will be similar to other eruptions from the volcano over the last 50 years, in the VEI ~3 vicinity.

Actually, the cited article said they expanded the exclusion zone around Krakatau from 1 kilometer to 3 kilometers which is better.

By Thomas Donlon (not verified) on 07 May 2009 #permalink

Are there any photos of the activity online?

By volcanophile (not verified) on 08 May 2009 #permalink

The current activity at Krakatau, as can also be seen in some photographs (for example, on Flickr.com) seems to be pretty normal for the past few decades at this volcano. I would guess it's in the VEI range of 2-maximum 3, representing a type of activity that is Strombolian or weak Vulcanian. Similar activity is seen since 1955 at Sakurajima in Japan, at Tavurvur (Rabaul, Papua New Guinea) since 15 years, and Stromboli in Italy since many centuries. I guess all the media hype about Krakatau is because this has been the source of the famous and disastrous 1883 eruption, but currently the volcano is probably many centuries away from a new cataclysmic, caldera-forming eruption. Remember, one of the main rules in volcanology is that the next volcano to produce something really big is probably one nobody is thinking about in this moment.

just to add to my previous post, if you follow this link to Flickr: http://www.flickr.com/search/?q=krakatau&s=rec , you will get a chronology of photos posted of Krakatau (most recent are first). Currently (8 May) there is a nice series showing relatively small-scale ash emissions, and people taking a bath in the nearby ocean, which testifies to the fairly modest size of this activity. Some photos also reveal that the 2007-2008 vent, which had bitten deeply into the upper side of the pre-2007 cone, is now nearly filled, and soon the cone might begin to grow in height again.

Thanks for the link Boris. I visited Krakatau in May 1997 when the alert level was 3 and the exclusion zone 5 km (similar to now). I was only there a few hours on a boat, and there were frequent small ash eruptions (with some glowing bombs) as in the recent pics on Flickr. BUT as we were pulling away after sunset, there was a huge, paroxysmal eruption with pyroclastic flows to the sea and incandescent material to 1000 meters or more above the crater, with an incredible firestorm of volcanic lightning above. I got the impression that the activity of this volcano can be extremely variable. The pics posted on Flickr may not be representative of the biggest explosions in the current activity.

I'd go there myself now, but have already committed to another trip. In June and July I plan to visit volcanoes of Alaska and then view the longest total solar eclipse of the century from the Japanese island of Suwanosejima which has a frequently erupting Strombolian type volcano. If I am lucky enough to see any good activity I will post the pics.

To depict the magnitude of that blast, is so pretentious, it could go bigger than last time, we dont know much at all about this beast. Get a head on your shoulders and remember, humans arent perfect and mother earth can do unexpected things, to try to guess otherwise.....well pretty much pretentious.

lol i like pie

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