volcanic hazards
eklemetti | April 5, 2010Quick hits for a Monday morning (however, the week did have a good start).
Lava fountaining on March 27, 2010 at the Eyjafjallajokull-Fimmvörduháls eruption in Iceland.
The Eyjafjallajokull-Fimmvörduháls eruption is still going strong with two active fissure - and a lot of tourists poking around as well. If you watch the webcams closely, you can even see the cars and hikers trekking up near the erupting basaltic fissure (except today, as there seems to be a blizzard). Not to say that people are getting a little, well, nonchalant, but there is a story of serving meals cooked on lava up by…
eklemetti | March 30, 2010Map showing the location of submarine volcano Marsili, near the Italian coast. Image from INGV.
The subject of submarine volcanism near Italy has come up before here on Eruptions but now it has made the jump into the worldwide media after some claims made by Enzo Boschi, president of the National Institute of Geophysics and Volcanology (INGV).
The long and short of what I can tell from the articles is that Marsili, a submarine volcano in the Tyrrhenian Sea, could be a threat to create a significant tsunami that would hit Italy (amongst other Mediterranean countries). The volcano lies only 150…
eklemetti | March 24, 2010I'm still playing catch-up after my week in the desert, so I've seen a lot of articles I've wanted to mention ... but a certain other volcano has taken up a lot of my time. However, I will attempt to make amends for that now.
By the way, would you believe Ubehebe Crater was closed? How do they close a volcano, anyway? However, I did get a great snap of a welded tuff on the road outside of Shoshone, CA.
A strongly welded tuff near Shoshone, CA. The dark interior is remelted volcanic ash/tephra surrounded by less welded pink tuff with abundant pumice clasts. Denison student David Sisak is on…
eklemetti | March 22, 2010The steam-and-ash plume from Eyjafjallajokull in Iceland, March 22, 2010.
Overnight, the Eyjafjallajokull eruption in Iceland added to its oeuvre, producing what is being reported to be a 8-km plume. Images of the plume (above) suggest (to me) that it is very water-rich, so likely this is the expanding(?) fissure interacting with snow, ice or groundwater, producing steam explosions. These explosions have some minor ash component to them, mostly from the shattering of rapidly cooled lava, but are dominated by steam.
The eruption appears to be continuing into its third day unabated. Flights…
eklemetti | March 21, 2010The fissure vent eruption on Eyjafjallajokull in Iceland on March 21, 2010.
The big news this morning is the eruption that started last night at Eyjafjallajokull in Iceland, producing a 1-km fissure vent. The pictures and videos I've seen so far have been quite impressive, with the classic look of a "curtain of fire", where basaltic lava erupts explosively from a linear array of vents - you can see the geometry in the image from the BBC/AP (above). Especially clear is the dual nature of the eruption, with both the explosive fire fountains and the effusive (passive) lava flows from the root of…
eklemetti | March 15, 2010The latest in my Volcano Profiles series, this one on Erta Ale in Ethiopia.
The summit crater at Erta Ale in 1994
Location: The Afar region of Ethiopia.
Height: 613 m / 2,011 feetTectonic setting: Erta Ale (meaning "smoking mountain") is part of the East African Rift, where the African Continent is tearing apart along a seam that runs from the Red Sea/Gulf of Aden (two other arms of the rift themselves) south through eastern Africa. Many of the large lakes of eastern Africa such as Lakes Albert, Tanganyika, Nyasa and Kariba fill rift valleys created by the cracking of the continental plate…
eklemetti | March 12, 2010Leaving for Death Valley tomorrow - I'll be sure to take some pictures of Ubehebe Crater and the volcano at the Mirage. This will likely be the last new post until about a week from now, but look for the Erta'Ale Volcano Profile, maybe a new Mystery Volcano Photo and I'll leave a thread open for any new volcano news.
Colima in Mexico.
Eruptions reader Tim Stone sent me this image from Japanese astronaut Soichi Noguchi's Twitpic feed - it is a stunner of the caldera on Jebel Marra in Sudan. The only known historical eruption for this volcano was ~2000 BC within the Deriba Caldera, but it has…
eklemetti | March 10, 2010Did I mention its a busy week?
The lava lake at Erta'Ale in 2008. Image courtesy of Stromboli Online.
Our Icelandic saga continues, with more earthquakes and more speculation/information on the parts of Eruptions readers. Keep up the discussion - I'll be fascinated to see who turns out to get closest to what actually happens, prediction-wise. The seismicity has quieted somewhat again in the last 12 hours, so we wait eagerly to see what comes next. Remember, Iceland is the land where volcanoes helped change history, so it is always fun to talk Icelandic volcanism.
The NASA Earth Observatory…
eklemetti | March 8, 2010Cleaning up some news ... busy week leading up to a field trip I am helping co-lead to Death Valley next week.
Ubehebe Crater in Death Valley, California
First off, I want to say how amazed I am at the great discussion that went on all weekend about the signs of potential activity in Iceland. It now appears that the earthquakes at Eyjafjallajökull may be waning, however the levels of seismicity have definitely bounced up and down over the last few days. However, the level and depth of the conversation is a testament to all volcanophiles out there. Nice job, folks.
For those of you into…
eklemetti | March 4, 2010Eyjafjallajökull, an ice-capped volcano in Iceland that last erupted in 1823.
We talked a few weeks ago of signs that there were increasing signs that an eruption could occur on Iceland - increased seismicity on the Reykjanes Ridge suggested that magma might be on the move. Now, we have two pieces of evidence that we might see activity at Eyjafjallajökull, on the southern side of the island nation.
First off, there is a focus of seismicity under the area of Eyjafjallajökull, with an especially large bump in the last 2 days. Both the number and magnitude of the seismicity has been marching…
eklemetti | February 26, 2010Catching up with some news:
Anatahan erupting in the northern Mariana Islands in 2003.
I ran across this article right before I got sick, but its been popping up around the interwebs (and is pretty interesting). It details a study in Molecular Ecology that suggests that populations of caribou in Canada's Yukon Territory were strongly effected by the White River Tephra. The White River Tephra is supposedly the largest Holocene plinian tephra (from a ash cloud fallout), with two components dating from ~1900 years ago and ~1250 years ago. The vent for the WRT is likely from a vent beneath the…
eklemetti | February 25, 2010The flu has retreated and I'm getting back on track. Huzzah!
I'll get back to the blog by posting this week's new USGS / Smithsonian Institution Global Volcanism Program Weekly Volcano Report. Looks like some interesting stuff in it ...
Looks like there were some small eruptions from Oldoinyo Lengai in Tanzania. The volcano is one of the few (only active?) carbonatite volcanoes in the world, erupting a lava composed primarily of calcium carbonate and sodium minerals with very little silica. It leads to the odd lava that erupt black (and cool ~ 500C) and cool to white, making it one of the…
eklemetti | February 18, 2010The Icelandic coast of Reykjanes where the Mid-Atlantic Ridge comes above sea level.
A number of Eruptions readers have noticed that seismicity along the Reykjanes Ridge that runs to the southwest of Iceland onto the island has increased over the last few days. Sure enough, checking the Icelandic Met Office page on seismicity on the island finds a lot of earthquakes on the southwest peninsula that is the manifestation of the Mid-Atlantic Ridge hitting the hotspot-related Icelandic landmass. The interaction between the Iceland plume and the Mid-Atlantic Ridge is complex, with a step in the mid…
eklemetti | February 17, 2010The rhyolite domes of Chaiten in Chile in an undated photo. Note how much of the previous Chaiten Caldera has already been filled by the new domes that started after Chaiten erupted in May 2008.
CNN International has a report that the National Emergency Office (ONEMI) in Chile has reinforced the "red alert" status of Chaiten (spanish). The volcano, which has been erupting since May 2008, had recently settled down to slow, but constant, dome growth. However, over the last 3 weeks, seismicity has been increasing at the rhyolite caldera, suggesting that we might be heading towards an upswing of…
eklemetti | February 16, 2010Not a lot of big news, but a lot of little news:
Soufriere Hills at night during the late January 2010 dome growth episode. Note the hot rock falls from the collapsing dome. Image courtesy of Photovolcanica.
This might not be new, but Dr. Boris Behncke brought the new webcam at the rim of Chaiten in Chile to my attention. You get a birds-eye view of the growing dome from the edge of the caldera - pretty nifty view for a once-in-a-hundred-years sort of event.
The NASA Earth Observatory has posted a close-up of the Soufriere Hills imagethat I posted yesterday, showing the February 11 plume. The…
eklemetti | February 15, 2010A couple bits of news:
The ash plume from the February 11, 2010 eruption of Soufriere Hills taken by theAqua MODIS camera. Image courtesy of the NASA Earth Observatory.
Flights have been disrupted in the West Indies since last week with the large dome-collapse eruptions of Soufriere Hills on Montserrat. The 10 km / ~35,000 foot ash plume is apparently lingering in the air at commercial flight levels, meaning delays, cancellations or long detours for many flights in the area. Flights in and out of Dominica, Guadelope, Montserrat, Anguilla, St. Kitts and Nevis have all been effected by the ash…
eklemetti | February 11, 2010Two impressive eruptions going on right now:
Soufriere Hills erupting on February 11, 2010. Image courtesy of the Montserrat Volcano Observatory.
Soufriere Hills just keeps on raising the bar during its new eruptive period. The volcano on Montserrat in the West Indies produced a 15 km / ~45 000 foot ash plume as the summit dome partially collapsed again. It was one of the biggest volcanic events at Soufriere Hills in the last 15 years, with 10-15% of the dome collapsing. One of the regional airlines in the West Indies have had to cancel flights due to the ash that has mainly been heading to…
eklemetti | February 10, 2010Sally Sennert from the Smithsonian Institution sent me an email to say that this week's USGS/Smithsonian Institute Weekly Volcanic Report will be delayed due to the inclement weather in the Washington DC area. She can't connect with the server, so the report can't be updated on the Smithsonian website ... so here it is! Look for it to show up on the Smithsonian site with all the bells and whistles as soon as DC thaws out.
And a big thanks to Sally for sending me the Report to post.
***PLEASE NOTE: Website posting of the SI/USGS Weekly Volcanic Activity Report for 3-9 February 2010 will be…
eklemetti | February 8, 2010A pyroclastic flow from the February 5 vulcanian eruption of Soufriere Hills. Image courtesy of the Montserrat Volcano Observatory (MVO).
UPDATE: See some amazing images of the recent eruptive activity over on Stromboli Online. {Hat tip to the Volcanism Blog via Eruptions reader CK.}
One event that didn't eat much coverage over the weekend, at least here in the U.S., was the large eruption and explosions at Soufriere Hills on Montserrat. The volcano has had a resurgent winter since have a quiet summer of 2009. This weekend's eruption produced an ash plume that reached ~6.1 km / 20,000 feet -…
eklemetti | February 8, 2010
This is a request more related to my teaching, but I thought I'd ask here. I'm trying to find copies of the UNESCO videos "Understanding Volcanic Hazards" and "Reducing Volcanic Risk". They were made by the Kraffts to help educate people on volcanic hazards, especially in developing countries. I've seen them both and they are great for introductory geology classes. However, the one source I knew of - the NW Interpretive Assoc. - doesn't seem to carry them anymore - and even if they did, the only format I know of is VHS, which is getting woefully obsolete.
So, do any of you know where I might…