Ash fall
eklemetti | March 19, 2009Mixing volcanoes and oceans seem to always produce exciting results. Whether it is something as simple as the ocean entry of a lava to something as impressive as a new island emerging, formed by volcanic eruption. Back in the 1960s, a previous unknown undersea volcano off the coast of Iceland erupted to form the island of Surtsey. The signs of the impending eruption were captured from start to finish, with Icelandic fisherman noticing "boiling seas", then steam explosions, then ash eruptions and finally volcanic tephra that formed the island itself. This was followed by lava flows and…
eklemetti | March 18, 2009
Image from AVO Hut webcam for Redoubt
After an exciting few days ... well, OK ... after an exciting few hours on Sunday, AVO has decided to lower the alert level at Redoubt in Alaska to Yellow/Advisory. The alert level was lowered last week after seismicity at the volcano returned to normal after weeks of rumbling (at Orange/Watch status), but then we are all caught by surprise when a phreatic explosion occurred (and AVO returned the volcano to Orange). However, this didn't lead to a new period of heightened seismicity, so back to Yellow we go (even with elevated gas emissions and a nice…
eklemetti | March 18, 2009
The eruption of Hunga Tonga Hunga Ha'apai volcano in Tonga looks to be a big one. Keleti Mafi, head of the Tongan geological service, calls this "a very significant eruption, on quite a large scale", which is no surprise considering some of the spectacular picture we saw of the eruption yesterday. In fact, the eruption is big enough that it has disrupted air traffic over Tonga, as Air New Zealand has issued a warning about the ash column - an ash column that has reached over 15,000 meters/50,000 feet! Luckily for the residents of Tongatapu, a mere 10 kilometers 50 km to the southwest SSE…
eklemetti | March 17, 2009
Now that Redoubt has decided that Yellow/Advisory is not to its likely and has returned to an Orange/Watch status, I'll continue bringing new updates of the volcano has events unfold.
And nothing much has unfolded since the phreatic explosion that occurred on Sunday. The current state of the volcano, according to AVO, is minor seismic unrest and that is about it. They do offer some more details of the events on Sunday:
An AVO overflight Sunday witnessed activity from 11:30 AM until about 3:00 PM and was able to document ash emission from a new vent, just south of the 1990 lava dome and west…
eklemetti | March 16, 2009
Oldonyo L'engai, Tanzania
As with most disasters, the best way to prevent a Katrina-like catastrophe is preparedness. The best successes in volcanic mitigation have been in places where the combination of monitoring, communications and practice fit together like so many legos in a set, allowing for a calm and orderly evacuation when the eruption, or signs of eruption, began (e.g., Rabaul in 1994). This is why it is always heartening to me to see articles about places trying to implement hazard mitigation plans for their volcanoes. Two examples are in the news today:
(1) Officials in…
eklemetti | March 15, 2009
Date: February 07, 2009 Image Creator: Bleick, Heather Image courtesy of AVO/USGS.
So much for my oh-so-eloquent eulogy for early 2009 activity at Redoubt.
AVO reports that it appears that the volcano has potentially erupted - or at least released a lot of steam and (possibly) ash.
Seismic activity at Redoubt has increased since about 13:00 AKDT and is continuing. An AVO observation flight reported that a steam and ash plume rose as high as 15,000 ft above sea level and produced minor ash fall on the upper south flank of Redoubt. Last reports are that the plume is now mainly steam.
Doesn't…
eklemetti | March 14, 2009I missed this the first time, but Click & Clack from NPR's Car Talk answered a question about how to volcano-proof your car.
If you want to hear it, click here. As usual, the guys in Cambridge (our fair city) do an excellent job with the information and the humor.
{Hat tip to Jen Glass at Arizona State}
eklemetti | March 13, 2009
2009 has been a busy year for Volcan Galeras in Colombia. The volcano has erupted at least twice this year already vigorously enough to prompt evacuations of the area. Galeras does tend to see cycles of eruptive activity, the last one started in 2000 after seven years of quiet. Many times, the eruptions are more visually impressive than hazardous (see the picture above from January 2008 from INGEOMINAS).
Luckily, Galeras is also once of the most watched volcanoes in South America. The INGEOMINAS (Colombian Geological Survey) staffs the Pasto Volcano Observatory (OVSP) to monitor the volcano…
sb admin | March 12, 2009
Welcome to version 2.0 of Eruptions, the blog on volcanic eruptions and volcano research in general. I've been writing this blog (starting over on Wordpress) over the last year or so, but now it has found a new home here at ScienceBlogs. If you're wondering what to expect if you're new to Eruptions, I'll be bringing news of volcanoes that are erupting worldwide, distilling the scientific jargon, dispelling the misinformation and commenting on what the effects of the eruption(s) might be. I'll also try to bring in any volcanoes in the popular media that gets my attention (alas, it has been…
eklemetti | February 20, 2009
Galeras, in Colombia, appears to have entered a new cycle of activity as it has erupted for the second time in a week. A large explosion occurred this morning that was accompanied by falling ash and rocks (ballistic bombs) from the event. It is unclear how far the volcanic products travelled from the vent, but Colombian officials did raise the alert level back to red and ordered new evacuations.
eklemetti | February 19, 2009Jonathan Castro has reminded me that I need a refresher on the proper terminology for ash columns related to volcanic eruptions. It is very easy to start mincing words and using them inappropriately - and that is the sort of sloppy reporting and discussion I am trying to avoid.
So, to refresh my (and our) memory on ash clouds and how to classify them, we can go back to one of the indispensable textbooks on volcanology, Cas and Wright's Volcanic Successions. The classification scheme they provide is summarized in the figure above. It shows the heights of various eruption columns and the…
eklemetti | February 19, 2009
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."Â So, we might have seen the oversteepening of the dome growing in the Chaiten caldera that lead to a collapse, producing (likely) a pyroclastic flow and either an accompanying plinian eruption as the pressure was released or an ash column associated with the pyroclastic flow itself. Now, I might not take Reuters word for it, but it makes sense…
eklemetti | February 18, 2009
I found this little press release that doesn't have a huge amount of information, but is interesting nevertheless. The Coordinating Committee for Prediction of Volcanic Eruptions of Japan (nice name) is putting seven volcanoes on "24/7" monitoring. That sounds like we might see a lot of eruptions in Japan soon ... except that their rationale was that these volcanoes "are likely to affect public life by erupting or becoming active in the coming 100 years". That is quite the window of eruptive opportunity! The question is what exactly "24/7" monitoring - does this mean that someone/something…
eklemetti | February 15, 2009
UPDATE 2/15/2009 20:30 PM: Marta Calvache of INGEOMINAS says that seismicity has all but stopped at Galeras after the eruption Saturday night, however the area will be kept on alert for more potential activity. However, even with the eruption, apparently there are very few people in the evacuation centers - never a good sign if something really big were to happen at the restless Colombian volcano. Â
Last night, Galeras, near Pasto in Colombia, erupted, prompting an evacuation of nearly 7,000 people living near the volcano. The first CNN article linked above, for some reason, says that…
eklemetti | February 6, 2009Just to keep us appraised of the situation at ever-steaming-and-shaking Redoubt:
From AVO (2/6/2009 11:05 AM)
Unrest at Redoubt Volcano continues.Â
After the tremor episodes of yesterday, seismic activity has remained slightly elevated relative to the last few days.Â
The volcano has not erupted.
That is about it. A few quick hits about Redoubt (as the world waits) include an article on potential redirected air traffic if the volcano erupts, an update mentioning that if the snow is falling during an eruption, radar won't pick up the ash until its at 15-20,ooo feet , how British Columbia is…
eklemetti | February 2, 2009
Mt. Asama near Tokyo did, in fact, erupt within the "two day" window predicted by the Meteorological Agency of Japan. The reports this morning put the ash column at ~2,000 meters (~6-7,000 feet), so relatively small, but big enough to dust parts of Tokyo (~145 km away) with ash. No evacuations are planned for the area around Asama, but people who live within 4 km of the volcano are to "take caution".Â
There are also new reports that Mt. Sakurajima in southern Japan erupted yesterday. Block were thrown up to a few kilometers from the volcano. The article suggests that ash spread as far as…
eklemetti | January 27, 2009
Sorry for the headline, but this is a quick update to emphasize the media and their love of destruction. For example, Redoubt is, indeed, showing signs of a pending eruption, but how large of an eruption is anyone's guess. Most news sources have been fairly restrained with their headlines, such as:
Rumbling Volcano has Geologists on Alert (although oddly filed under "strange" news)
Attention Alaska Pilots - Alert Mt. Redoubt eruption may be Imminent (note that this one incorrectly says Redoubt is on "red" alert)
Inlet volcano Quieter but still Simmering
Alaskan Volcano Rumbling
You get…
eklemetti | January 24, 2009
It is hard to believe that the eruption at seem to come out of nowhere at Chaiten started over 8 months ago now, and apparently is still not showing many signs of abating. I did get a chance to see some great talks and posters at AGU last month about the Chaiten eruption, with the key points I took away being that Chaiten is erupting a very crystal poor rhyolite (<1% crystals) and that it seems that the source of the magma is relatively deep in the Andean crust. Also, there are some indications that the eruption at Chaiten may have been tectonically instigated - i.e., that earthquakes in…
eklemetti | January 24, 2009
We really don't know much about the current and ancient volcanism on Antarctica, but researchers from British Antarctic Survey claim they have found evidence of subglacial eruptions in western Antarctica, mostly in the form of ash and volcanic debris intercalated with the ice. It would not be surprising if there was active volcanism underneath the ice sheets of the continent. However, they then take it one (or multiple) step(s) further by saying that this subglacial volcanism might explain the warming seen on the western side of the continent. Now, that would be very surprising as the…
eklemetti | December 11, 2008
Sometimes I wonder if we know more about the fates of people who died in a volcanic eruption over 1800 years ago than we do about most people who died in any given eruption this year. Not that there is anything particularly wrong with that - we're fascinated by both volcanoes and Roman antiquity - but the level of detail done for the victims of Vesuvius in 79 A.D. is stunning.
Considering that this blog got started (to an extent) thanks to our cultural obsession with Pompeii, I thought it fitting to post a bit about a recent report on the last moments of a family in Pompeii. Nothing really…