explosive eruption
eklemetti | June 17, 2008
Over the weekend, Mt. Etna (Italy) had some spectacular Strombolian fire-fountaining. Lucky for us, Marco Fulle and a group went up to the summit on Friday (the 13th) and got some great pictures of the current (ongoing) eruption which have been posted on Stromboli Online. Sounds like the eruption has been increasing in the past week, so it could be a busy summer in the Aeolian Island of Italy.
eklemetti | June 16, 2008
The newest reports out of Chile are indicating that the eruption at Chaiten has reached levels of intensity not seen since the eruption first started over six weeks ago. I have to admit, that isn't a good sign in terms of keeping the volcanic edifice in one piece. There have been frequent, small (<M3) earthquakes along with "rumbling noises," which might indicates that the domes are collapsing to form pyroclastic flows. Alternately (and need I remind you, very speculatively) it might be the the edifice itself beginning to show the wear of this long eruption and the emptying of the magma…
eklemetti | June 13, 2008
So, this was a bit of a surprise to me. Six weeks into the Chaiten eruption in Chile, apparently the volcano has picked up the tempo again. Not much in the report except that apparently two new vents/craters have opened, there is an increase in ash emission and seismic activity. What this might be is difficult to ascertain from the report, but it could indicate that the volcano might be heading down the road toward a collapse, such as the one previously alluded to by scientist-in-charge Luis Lara. Another report - albeit almost identical to the first - does mention in the headline that the…
eklemetti | June 13, 2008
Authorities in New Zealand have issued an alert for White Island. After a fairly sizable earthquake (M=5.4) near the island, the state agency that oversees volcanoes (GNS Science) is warning people to stay away from White Island for the next 48-72 hours on fears it might erupt. Normally, just because there is an earthquake near a volcano you don't instantly jump to the idea that it will erupt, but the 5.4 and subsequent earthquakes have been both near White Island and shallow (5-km depth), indicating it could very well be related to magma moving under the system.Â
White Island itself is a…
eklemetti | June 12, 2008
Most people don't realize that a majority of the earth's volcanoes are underwater. That is to say, the mid-ocean ridge system that runs along the bottom of all the major oceans can be considered one big volcano. However, thanks to its location deep underwater, we have only had second- or third-hand evidence of eruptions at mid-ocean ridges or seamounts.
Not any longer according to my graduate alma mater, Oregon State University. An active eruption was captured at Brimstone Pit in 2006, near Guam, by a team looking for hydrothermal activity at the sea's bottom. The eruption appears to be a…
eklemetti | June 10, 2008
One of the most famous eruptions in human history (at least recent history) is the 1883 eruption of Krakatau in Indonesia, made (more) famous by Simon Winchester's book (and the inappropriately named film Krakatoa: East of Java ... hint: look at a map). Since the cataclysm eruption, a new volcano has risen where the old one once stood. Anak Krakatau (I believe loosely translates to "son of Krakatau") is a fairly active volcano, producing Strombolian explosive eruptions - fairly mild - that threw volcanic bombs and debris onto the island and into the surrounding ocean (thus, building up the…
eklemetti | June 9, 2008
Today, I saw a report that a dome on Arenal in Costa Rica had collapsed last Friday (report in Spanish, but good picture of the event), producing a block & ash flow that left a 800-meter scar on the volcano's flank. No one was injured during the avalanche, but tourists were evacuated as a precaution. There have been minor rock fall related to the andesite lava that has been erupting over the last year, but apparently this is the first major avalanche.
This shows the fine line between an effusive (lava flow dominated) eruption and explosive (pyroclastic dominated) eruption. Although this…
eklemetti | June 8, 2008
I mention this little human interest piece mostly because I am especially found of Mt. Tarawera (note: this link goes to the GVP page for Okataina, the volcanic cluster of which Tarawera is a member)Â in New Zealand. This Tuesday (June 10) is the 122nd anniversary of its most recent eruption, the 1886 eruption that erupted the Rotomahana Basalt. The eruption itself was relatively unique as it was a basaltic eruption that was almost entirely dominated by explosive eruptions of basaltic tephra (see illustration above). This likely means that the basalt was highly enriched in volatiles gases…
eklemetti | June 6, 2008
Reuters has a short video showing some of the damage inflicted on Chaiten by the volcano of the same name. Looks like the ash, lahars and flooding have wiped out at least a third of the town (according to the voice-over) ... and in a sense, Chaiten (the town) lucked out as the destruction could have been a lot worse.
eklemetti | June 6, 2008
A few reports this morning that Mt. Soputan, on the island of Sulawesi in Indonesia, is currently erupting. The reports indicate that there has been a lot of seismic activity and some ash emitted from the volcano. As with many volcanoes in the densely populated nation of Indonesia, there are people living on the slopes of Mt. Soputan and the authorities are preparing to evacuate them, if necessary. The last eruption at Soputan was way back in ... 2007 (see photo above), so it seems like the volcano is another one of many active Indonesian volcanoes.
eklemetti | June 4, 2008
If you needed any evidence that Chaiten is still erupting quite vigorously, just check out the MODIS image taken on 5/31 (above). The eruptive column is still delivering ash across southern Chile, over the Andes and into Argentina. This eruption just keeps on impressing me with its duration and magnitude - this is one for the ages (well, human ages).
eklemetti | May 30, 2008
We've been hearing a lot of conflicting reports about the state and future of the Chaiten eruption. Now ending its fourth week of eruption, Chaiten was said to be easing up a bit, but recent reports have Luis Lara from the SERNAGEOMIN still worried about a potential collapse, followed by a devastating eruption. I'll have to take his word for it as the explanations in the article don't really make a lot of sense. It sounds like both Lara and Dr. Petrinovic (Argentina) are worried about dome collapse, but that would just form large pyroclastic flows ... unless the dome collapses enough to…
eklemetti | May 29, 2008
This isn't really new activity, but a report on the ongoing activity at Soufriere Hills on Montserrat in the West Indies. Soufriere Hills is a composite volcano that has been erupting for almost 11 years now, producing pyroclastic flows and ash fall that have wiped out entire towns on the island of Montserrat. Most of the activity is caused by dome collapses, where the viscous dacite lavas will erupt to form domes that then become oversteepened and collapsed due to gravity. This material is still hot (usually) and forms the deadly pyroclastic flows. Sounds like there have been a few dome…
eklemetti | May 27, 2008Although the mainstream media seems to have lost interest in the Chaiten eruption beyond the "human interest" (or should I say "salmon interest") aspect of the eruption, there is still a lot going on at the volcano. The SERNAGEOMIN recently released this excellent photo of the erupting caldera:
What is pretty clear here is thank a new rhyolite dome is erupting on top of the old dome. (On a side note, when I was visiting the Smithsonian last week, we were all lamenting the fact that no one has come out and said what composition this lava is? I'm 99% convinced it is rhyolite, e.g., high silica…
eklemetti | May 26, 2008
I'm always amazed by the number of volcanic eruptions captured by satellites that we might not have ever even had known occurred otherwise. Case in point is Rabaul on the island of New Britain in Papua New Guinea. An Aqua satellite captured this shot of Rabaul erupting on May 20th, leaving a gorgeous plume heading off into the Pacific. Sure, most likely someone might have noticed the eruption, but its good to see that we can find eruptions going on even when we're not really looking.
Rabaul is a caldera volcano that is most famous for the simultaneous eruptions of Vulcan and Tavurvur in 1994…
eklemetti | May 26, 2008
Tungurahua, one of the most active (and harder to pronounce) volcanoes in the Andes, has been experiencing explosions over the last few days. Not much in the report beyond the 125 explosions, increased seismicity and ashfall around the volcano. This is fairly typical behavior of Tungurahua: Strombolian-style eruptions (see the picture above for a great example) with ash and blocks being ejected from the crater. The volcano has been continuously erupting since 1999.
eklemetti | May 26, 2008
People living around Semeru Volcano, Indonesia, have been put on alert for a potential eruption. Indonesia's Centre for Volcanology and Geological Hazard Mitigation has put the volcano on level 3 (of 4) alert and said "not to conduct activity at a radius of 4 kilometres from the crater, especially around the south-east of the volcano's slopes." There have also been reports of ash clouds (or steam) being vented from the crater.
Semeru is a very active volcano in a country full of active volcanoes. It has been erupting since 1967, quite a long span for any stratovolcano to be constantly…
eklemetti | May 26, 2008
Everyone loves a "supervolcano"*. According to a recent report, Los Angeles will be erupting from underneath Yellowstone Caldera (Wyoming). OK, not really, but apparently there has been 7 cm of uplift underneath the footprint of the Yellowstone Caldera since 2004, which is a pretty good amount of uplift. Whether this uplift is caused by new magma intruding, volcanic gases collecting or hydrothermally spawned (however, in the article, we are to believe these unnamed "researchers" that it is magma). I'll keep an eye out for more on this, but it sounds like this is just another "more uplift!"…
eklemetti | May 19, 2008
It has been rather quiet on the volcano news front over the weekend. A couple tidbits:
- There are some new data showing the sulfur dioxide flux from Mt. Etna (Italy). The image above is an eruption of Etna from 2001 (and it makes a great wallpaper).
- I've heard very little about Chaiten lately, mostly because I don't think much has changed. The last update provided by the SERNAGEOMIN was on 5.16 (in spanish) and pretty much that is exactly what it says: the volcano continues to erupt. Apparently some USGS folks will be arriving on the scene soon as well. Most of the town of Chaiten has…
eklemetti | May 17, 2008
Happy 28th anniversary of the 1980 Mt. Saint Helens eruption. The volcano had a catastrophic collapse of one side of the edifice that triggered the climatic eruption. Enjoy this clip from the CBS News from 3 days after the eruption.
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