explosive eruption
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 11, 2009I get a fairly steady stream of emails from Eruptions readers, some of which are very worth a post, but sometimes it takes me a while to get around to posting. This is my second attempt to catch up on these mailbag emails. Remember, feel free to email me questions or comments whether you want.
Reader Aldo Piombino sent me an email last month after my post on potential Antarctic volcanism asking about some more unknown volcanoes. He brings up Mt. Marsili in the Tyrrhenian Sea (including a post of his own, in Italian), a volcano of which I was not aware. It is a submarine volcano (info on…
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 6, 2009
For those of you interested in what happens in the realm of submarine volcanism, I can pass on some tidbits I've gotten about NW-Rota 1, a submarine volcano in the Mariana Islands (see bathymetry above). Dr. Ed Kohut (Petrogenex), a friend of mine from my days at Oregon State Univ., is currently on a JAMSTEC research cruise in the Mariana Islands, visiting the area about NW Rota-1. He reports:
"We just reached NW-Rota 1. It is still actively erupting. To put that in perspective, it has been observed erupting every time it has been visited since 2003. Today's actvity is not as vigourous as…
eklemetti | February 5, 2009
Bored with waiting for Redoubt to erupt? Well, Nevado del Huila in Colombia looks like it is also on the eruption watch list. A fly-over of Huila performed by Colombian officials (unclear from the article if it was done by National Emergency Management or INGEOMINAS) revealed a large lava dome growing in the crater, suggesting that an eruption might follow considering all the lava being extruded. This eruption might come in the form of an explosion caused by the collapse of this lava done - the collapse itself could generate a pyroclastic flow and the release of pressure on the underlying…
eklemetti | February 1, 2009
UPDATE 2/1/09 5:02 PM Pacific: Indeed, Asama did erupt today. The eruption was relatively small, throwing ballistic clasts up to 1 kilometer from the vent and ash into the outskirts of Tokyo.
Redoubt in Alaska has dominated the volcano news as of late, but it is clearly not the only volcano on Earth that is showing signs of eruption right now. The Meteorological Agency in Japan has just raises the alert level at Mt. Asama and warn that the volcano could erupt in the next "two days". Asama is ~150 kilometers from Tokyo and is very active (see above), having last erupted in September 2008. The…
eklemetti | January 31, 2009
The "eruption watch" continues at Redoubt ... Saturday revealed that things are getting hotter at the summit near the 1989/1990 dome (see picture above that made Redoubt famous in 1989). The overflight of the volcano revealed new holes in the summit glacial and a multitude of muddy streams formed from the meltwater. This area of very intense fumarolic activity is just below the 1989/1990 dome (~7,100 feet) and has been growing over the past few days. They also report an area at ~9,000 feet on the volcano that shows signs of ice collapse, indicating heat from underneath the snow and ice (…
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 | January 19, 2009
One of the more impressive areas I visited while in New Zealand was the Waimangu Valley near Mt. Tarawera (above). The valley itself was created by blast explosions (phreatic explosions) during the 1886 eruption of Mt. Tarawera. These eruptions cut right down the axis of the rhyolite domes (most of which erupted ~1305 A.D.) and extended off the volcanic edifice to form the valley to the west of the volcano. In the valley, no juvenile lava was erupted, instead explosions carved out large pits that formed the Waimangu Valley and today the valley is filled with lakes and thermal features (below…
eklemetti | January 1, 2009
Right as Yellowstone is getting interesting (or at least had signs of interest), Eruptions is going on a bit of a break again starting January 2. This time it is because I'm off to the North Island of New Zealand to do some field work. I'll be headed to Tarawera (hopefully both the 1305 and 1886 eruption deposits), Taupo, Tongariro, the area around Rotorua and maybe even White Island (amongst other). I won't have my MacBook, but I will have my iPod Touch, so I'll try to keep track and make brief posts if something big comes up, but feel free to use this post as a clearinghouse for any news…
eklemetti | December 29, 2008
Some more information is coming out about the activity at Koryak (aka Koryaksky) in Kamchatka. Russian geologist Alexei Ozerov says that the activity at Koryak (note: the image in the article linked here appears to have nothing to do with Koryak) has started with more power than the last known eruption of the volcano in 1956. He also mentions that the volcano is already a danger to aviation in the area (as the closing of the Petropavlosvk-Kamchatsky Airport suggested).
We also have some great images of the volcano, showing the vent on the side of the volcano (see above). It is hard to tell…
eklemetti | December 28, 2008
News is filtering in that Koryak (aka Koryaksky) Volcano in Kamchatka might be heading towards an explosive eruption. The details are scarce, but it seems that a breach on the northwest slopes of the volcano might cause an explosive eruption, however, it is not clear why this is. All this talk has caused the Petropavlosvk-Kamchatsky Airport (~13 miles northeast) to close in fears of this potential activity.
Koryak is yet another potentially active volcano on the Kamchatka Peninsula, along with currently active Bezymianny, Kliuchevskoi, Karymsky and Shiveluch. The last eruption at Koryak…
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…
eklemetti | December 10, 2008
The latest eruption of Sourfriere was captured from space, and NASA has just released the MODIS picture of the volcano in action. The image (above and linked) was taken 2 days after the first explosion of this unanticipated and unexpected eruption - December 4. You definitely get the idea of how much of the island of Montserrat is taken up by the volcano itself (pretty much all of it). Not much else to report on Soufriere Hills beyond the update from MVO (via SI/USGS) for the end of last week:
On 3, 4, and 5 December small, relatively slow moving pyroclastic flows traveled no more than 3.2…
eklemetti | December 5, 2008
The blasts and pyroclastic flow from earlier this week at Soufriere Hills in Montserrat were not the only show planned for the week, apparently. The volcano continues to erupt, with reports of continued ash and ballistic glowing bombs being erupted. These eruptions are the first major ones at Soufriere Hills in 6 months, but are apparently unique with no real precursors such as seismicity (well, none identified as of yet).
eklemetti | December 3, 2008
Just to keep everyone on their toes, Soufriere Hills on Montserrat in the West Indies erupted today. The eruption produced a number of explosions and a pyroclastic flow that originated from the west side of the lava dome at the summit of the volcano. However, the most interesting bit comes from the Montserrat Volcano Observatory (MVO) report I received this morning:
"The explosion happened without any warning. There was no precursory seismic activity."
Sounds like it could have been a dome collapse caused by a rapid release of gas/steam? The explosion apparently threw blocks as far as a…
eklemetti | November 23, 2008
I've found a few more details about the ongoing activity at Huila in Colombia, including a video report from the BBC. It seems that the eruption at Huila is a photocopy of what happened at Nevado del Ruiz in 1985 in its style: hot ash and gasses erupted from the crater melted ice/snow near the summit to create a lahar - a deadly mix of volcanic material and water that ends up like a surging flow of liquid concrete. The lahars travelled down the Rio Paez valley (see linked map - the landslide on the map is not volcanically related).
Beyond the unfortunate victims caught in the mudflows, many…