caldera
eklemetti | May 15, 2009Volcano news ahoy, today brought to you by Islands.
Lake Kivu, located along the border the Democratic Republic of the Congo and Rwanda
A gorgeous satellite image (brought to us by the NASA EO) of a steam plume and ash from the ongoing eruption at Shiveluch in Kamchatka. The ash distribution stands out remarkably well on the white snow, with the central circle of ash near the vent/dome and then the wind-aided ash blanketing the terrain to the northeast of the volcano (and a little bit to the south).
Nature has a post reminding us that one of the big hazards at Nyiragongo/Nymuragira is not…
eklemetti | May 3, 2009
Chaiten erupting in May 2008. Image courtesy of ONEMI.
Speaking of anniversaries, this weekend is the one-year mark for the Chaiten eruption (in spanish) in Chile, the first eruption at the volcano in ~9,000 years. Yes, indeed, the rhyolite eruption that caught most everyone by surprise is still going strong one year later, with two domes growing within the caldera (in spanish). The eruption produced some of the most impressive and sustained ash columns in years (see below) - climbing to 16 km/9 mi, abundant lahars and pyroclastic flows from the emergence and growth/collapse of the domes and…
eklemetti | April 21, 2009Well, after lamenting the slow volcano news, things are beginning to pick up again. Beyond the news of a potential increase in activity at Anak Krakatau, there are a few other newsworthy bits that have come up:
Mt. Kerinci in Indonesia
Mt. Kerinci in Indonesia is showing signs of eruption. The volcano is the highest mountain on the island of Sumatra, reaching 3,800 m / 12,400 feet and last erupted in March 2008. Its volcanic activity is marked by small (VEI <2) explosions of ash and tephra. Currently, the volcano is experiencing increased tremors and minor explosions that rained ash on a…
eklemetti | April 20, 2009
Anak Krakatau erupting in 2007.
There is a report out tonight that activity might be increasing at Anak Krakatau in Indonesia, however, it is unclear whether it is actually increasing or not. People are evacuating the coastal area of the Sunda Strait to Bandarlampung in fear that a major eruption of the volcano is on the horizon. However, the Volcanology and Geological Disaster Mitigation Center (PVMBG) in Indonesia has not changed the alert status at Anak Krakatau and it remains at 2 of 4 (~Orange Status). The volcano has been erupting almost constantly for the last few years, producing…
eklemetti | April 13, 2009
Chaiten erupting on January 19, 2009. Image courtesy of the NASA Earth Observatory.
It is hard to believe that we are less than one month away from one-year anniversary of the beginning of the eruption at Chaiten (and with it, the one-year anniversary of this blog!) The volcano in southern Chile is still erupting away, creating at least 2 dome complexes within the older caldera. These domes have been experiencing periodic collapses, creating block & ash flows, some of which have made it out of the caldera and down close to the ghost town of Chaiten. Along with the block & ash flows,…
eklemetti | April 11, 2009
Fernandina volcano in the Galapagos.
Fernandina in the Galapagos has entered a new eruptive phase according to the Geophysical Institute (GI) at the National University of Ecuador (in spanish). Satellite images show a new crater and ash column from the volcano and the GI will look for evidence of new lava flows beyond the "hot points" spotted on the satellite images.
UPDATE 4/11/09 9PM: I thought I'd add a link to the story in English now that I found one. There are also some pictures of the lava flows from La Cumbre (There is some confusion about name - Fernandina and La Cumbre are the…
eklemetti | April 9, 2009
Tambora, Indonesia
There are big eruptions, then there are big eruptions. On April 10, 1815, Tambora, a volcano in Indonesia, produced one of the largest eruptions in human history. This eruption produced what became known as the "year without a summer" after the volcanic aerosols from the eruption produced some of the coldest summers in many parts of the world. The Tambora eruption in 1815 was a VEI 7, on a scale that goes to, well, 7*, putting it in a class of some of the largest and most violent eruptions imaginable - and I, for one, can hardly imagine what might happen if an eruption of…
eklemetti | March 31, 2009
Yellowstone Lake eruption, April 1, 2009
Well, after all the seismicity and uplift at Yellowstone caldera over the last few years, something finally happened. Early this morning, without much warning, an eruption occurred in Yellowstone Lake (see above) and sent steam and ash up 50,000 feet above the park. Luckily, no one was injured or killed in the event as we're well ahead tourist season, but it is unknown how this might affect access to the park for this summer.
Now, whether this eruption is really just the caldera "letting off steam" so to speak, possibly in the form of a phreatic…
eklemetti | March 20, 2009
Now that people have been able to get a better look at the are about Hunga Tonga Hunga Ha'apai, we've been able to get a better idea of what sort of eruption occurred. The explosions and ash/tephra from the eruption have all but wiped out life on Hunga Ha'aapai, as the island contains one of the vents, while the other is only 100 meter off shore of the island - although the tephra erupted so far have joined the new vent and the island. You can clearly see ash mixing with the water around the island and the island itself has been blackened by the coating of ash. This is a classic volcanic…
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
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
Image from keizo/weblog
Hunga Tonga-Hunga Ha'apai (how's that for a name?), a shallow seamount in Tonga, appears to have erupted. An air passenger snapped some pictures of an eruption occurring in the ocean between the Tongatapu and Vava'u and pilots in the area report that (unsurprisingly), the feature is new.
Hunga Tonga-Hunga Ha'apai - at least the part above water (look in the bottom of the image, the islands are marked in green) - is made of two small islands that cap the main seamount and ring the volcano's caldera. The last known eruption from the volcano was in 1988 - over twenty…
eklemetti | February 25, 2009
The people who remain in Chaiten face the potential for a devasting pyroclastic flow, so says Jorge Muñoz of the SERNAGEOMIN in Chile. The volcano is still producing large ash columns on Tuesday and a flyover of the dome forming inside the caldera has lead to the concern that a collapse on a larger scale than those seen last week could wipe out the town for good.
The government hopes news like this from volcanologists might convince the last remaining residents of Chaiten to leave, but no indication of this has come to pass. In fact, things sound like they're getting heated in the fight…
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 | 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 1, 2009
I just wanted to point folks to an interview in US News & World Report with the USGS scientist-in-charge of the Yellowstone Volcano Observatory, Dr. Jacob Lowenstern. He plays down the swarm, noting that things like this happened in the 1980s and that Yellowstone has seen over 80 eruptions in the caldera since the last "supervolcano" eruption 640,000 years ago. I know Dr. Lowenstern pretty well, and even at AGU when I talked to him (before the swarm), he seemed to play down the huffing and puffing the caldera experiences on a yearly basis. It would take much more activity to get the YVO…
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 31, 2008
Yellowstone looks to be keeping everyone on their toes as we ring in 2009. The earthquake swarm reported earlier this week is continuing, with multiple events between 2-3.5 on the Richter Scale. Again, the folks monitoring the caldera - this time the Univ. of Utah - play down these events as normal for any active caldera system ... and they're very likely right. However, the media love to bring up the "supervolcano" angle and we're even getting expert opinion from (wait for it) Garrison Keillor!. Â The earthquakes are just normal earthquakes so far - none of the dreaded/anticipated harmonic…
eklemetti | December 29, 2008
2008 is almost finished and we've seen one of the few high-silica rhyolite eruptions in the past 100 years at Chaiten in Chile. Chaiten was definitely not high on the list of potential locations for a rhyolite eruption worldwide. However, Yellowstone Caldera in Wyoming definitely is high of the list because it has erupted a lot of rhyolite over the last few 100,000 years (even discounting the big so-called "supervolcano" eruptions).
This is why the current news of an earthquake swarm at Yellowstone is, in the very least, really interesting. The earthquakes - over 250 of them - started…
eklemetti | November 11, 2008
I just got back from a 4 day field trip to the Long Valley Caldera in eastern California, so I'm a little behind on posting. The field trip was great and I had a chance to see a lot of pumice, a lot of welded tuff (in the form of the Bishop Tuff, the large ignimbrite that erupted from the Long Valley Caldera ~760,000 years ago) and got to lead the part that looked at the Mono domes (too bad snow covered the Inyo Domes). Pictured above some puffed obsidian - the layers are obsidian and vesicle-rich obsidian - that were erupted, cooled, expanded and cracked (known as "breadcrusting"). This is…