Shiveluch has started off 2014 with a bang as well. Ash plumes reaching 7-9 km (25,000-30,000 feet) along with pyroclastic flows have been occurring due to the same cycle of dome building and collapse that we’re seeing at Sinabung — a very standard behavior for arc volcanoes like these two. Thanks to its remote location, Shiveluch doesn’t pose much in the way of human hazard, but some villages on the Kamchatkan Peninsula have had some minor ash fall due to the eruptions. You might be able to check out the action on the Shiveluch webcam as well.
Italy
I meant to mention this last week, but Dr. Boris Behncke had a brief post on the rumbling at the Northeast Crater of Etna. Over the past year, much of the action has been at the New Southeast Crater, but that is a recent phenomenon. Although the Northeast Crater has taken a back seat lately, minus some ash emissions, apparently there is some speculation that this could change based on its current state of degassing.
El Hierro Volcano activity report – Continued (mixed) upward deformation – New deformation data (Dec. 26)
Last update: December 26, 2013 at 12:10 pm by By Armand Vervaeck
2013-12-26 12:07 UTC To make the deformation graphs a bit easier to read for our readers, we have created a map showing the axis where the most lifting has been noticed until the latest incoming data. Most earthquakes did occur and continue to occur to the East and South-East of the HI08 GPS station
2013-12-26 11:00 UTC IGN has just released new Ultra Rapid deformation data showing a continuous lifting in some parts and a stagnation in other parts.
The island inflates further with 1.5 cm in both HI08 (El Pinar) and HI09 (La Restinga) which brings the strongest inflation area 7 cm higher than prior to the crisis.
HI02 and HI03 (Sabinosa – El Golfo area) are stagnating or even deflating a little.
HI01 and FRON are lifting also another 1.5 cm.
Will be followed …
Click on this image to see the details in full size
Click on this image to see the details in full size
2013-12-26 09:16 UTC Still only a few earthquakes since midnight, but this may change based on the latest data not yet included in the list.
Volcanic tremor (indicating magma movement, still deep below the island) has been recorded by many instruments on the island.
The Upwards deformation was also confirmed by the latest Involcan/Uni of Nagoya PINA GPS station. In order to reference the current deformation vs the deformations from earlier crisis, we have included the PINA Involcan/Uni of Nagoya GPS data sheet (unfortunately the Pre-2012 data is not included). The increase we witness now can indeed be called “spectacular”.
2013-12-25 22:58 UTC – A very interesting new episode in the current crisis. A calm seismic period but a continued deformation, both vertical and horizontal. In earlier crisis, once the seismic unrest stopped, also the deformation leveled or stagnated. No the lifting continues in most points as the latest IGN GPS stations are showing. All this means that this crisis is not over yet and that new seismicity is evident when the island is pushed upwards. The Upwards deformation data are really spectacular (U side of the graphs) – In only 3 days HI09 (La Restinga) lifted 6 cm! and HI08 (El Pinar) 5 cm. But not only the South-Eastern side of the island was lifted, but also most of the El Golfo area with an average of 4 cm.
for more information, go to: http://earthquake-report.com/2011/09/25/el-hierro-canary-islands-spain-volcanic-risk-alert-increased-to-yellow/
These UFO videos were recorded directly from the live volcano cam. Many volcanos around the world have been suspected of being entrances to alien bases, even a few in the US, but this volcano has something most of those don’t have…several live cams from different directions! This is an important tech tool in revealing the existence of aliens. SCW
Meanwhile in Italy, Etna had yet another paroxysm, this time less than a week since its last one. This one produced a significant ash plume with lava fountaining, but little-to-no lava flow activity. One of the more impressive videos I’ve seen for the eruption was one taken by hikers on Etna who had basaltic scoria rain down on them. VolcanoDiscovery also posted a time-lapse of yesterday’s eruption.
Etna in Italy erupting from two vents simultaneously on October 26, 2013. Image: Dr. Boris Behncke / Flickr.
Sometimes it takes as many days as the meeting to catch back up afterwards — which is clearly the case for me after GSA this year. Finally getting almost on track as we hurtle into November.
Volcano news!
Italy
So, like clockwork, right as I leave for Denver and the GSA meeting, a volcano decides to put on a show. This time it was Etna. After six months of relative quiet, the Sicilian volcano put on quite an impressive show (see above), with eruptions from two craters simultaneously: the New Southeast Crater and the Northeast Crater (see above). Both of these eruptions were explosive, producing plumes that reached a few kilometers over the volcano and spread ash across the area of eastern Sicily. At the same time, a lava flow issued from the saddle between the two crater, meaning that Etna has erupting from at least three different vents simultaneously during the October 26 eruption. Dr. Boris Behncke of the Osservatorio Etneo posted an excellent video of the action during the 10/26 paroxysm that shows the lava fountaining that occurred from the New Southeast Crater. Towards the end of the video, you can see some great examples of strombolian activity during the waning stages of the eruption from the New Southeast Crater as giant bubbles pop in the conduit of the erupting vent. Each “pop” of that bubble would send out thousands of lava bombs, and created the booming sound you can hear on the video. Dr. Behncke also posted a great sequence of images and a story behind the remnants of a former volcano observatory on Etna. Right now, only the antenna of the former building sticks out above many years of volcanic debris, but the October 26 paroxysm lava flow came with 1 meter(!) of knocking down even that last vestige of the structure. Things have settled down at Etna after this eruption, but as we all know, the volcano can ramp up quickly to a new paroxysm.
Indonesia
Across the world in Indonesia, Sinabung continues to produce explosive eruptions. Right now, these discrete event have been producing ash plumes that reach up to 7 km (23,000 feet) over the volcano. All of this activity at Sinabung prompted the PVMBG to raise the alert status at the volcano to its second highest setting (siaga – alert). This move increased the exclusion zone around the volcano to 3 km and ~1,300 more people have evacuated the slopes of the restless volcano. Elsewhere in Indonesia, looks like people want to add some fearmongering to the menu (as if actively erupting volcanoes weren’t enough). The IB Times has an article proclaiming “Lake Toba’s Volcanic Underbelly ‘Could Erupt at Any Time’“, snatching a poor choice of words by the president of the Indonesia Geological Experts Association, Rovicky Dwi Putrohari. The article itself sounds like an attempt by the IGEA to promote its annual conference that occurred this week — nothing like capitalizing on fear of the next eruption from a caldera to grab the media’s attention.
Landsat 8 OLI image of Iliwerung in Indonesia on Lembata Island, seen on August 12, 2013. The dark grey area is the volcanic complex, while the grey box marks where the new submarine eruption from the Hobal vent is likely occurring. Image: USGS/NASA.
Interesting news coming out the of the East Nusa Tenggara Province in Indonesia. An undersea volcano off of the southern coast of Lembata unexpectedly erupted over the last few days, producing strongly discolored waters and a plume (likely made dominantly of steam) that reached 2 km (6,500 feet). The latest GVP Weekly Volcanic Activity Report also mentions incandescence noted at the sea’s surface. According to news reports, the volcano is called “Mt. Hobalt”, however, in the Global Volcanism Program‘s database, no such volcano exist. There is a Hobal that is part of the larger Iliwerung complex in the right area of Lembata, so this seems to be the volcano that is erupting. This volcanic complex has been producing diffuse fumarolic activity since the beginning of the month and the PVMBG noted that seismicity has increased sharply in this area as well. This new eruption from Hobal has prompted the PVBMG (Center for Vulcanology and Geological Disaster Mitigation) to put Hobalt on a Level II alert and warned fishermen and tourists to avoid the area. There have been some fears that this activity near the coast could produce a tsunami, but so far those fears are unfounded. This would be the first eruption from Iliwerung since 1999 and much of the eruptive activity at Iliwerung has been from Hobal since 1973. The last known subaerial eruption from Iliwerung was in 1948 (but records can be incomplete across Indonesia).
Meanwhile, the continued eruptions at Rokatenda has caused a larger-scale evacuation of the region around the volcano. Seven hundred housing units are to be constructed for people who have had to leave their homes since October 2012 due to the ongoing activity. Recently at least 6 people died from a pyroclastic flow that swept across a beach where villagers were living on the island volcano.
Shot of a new lava dome seen on July 7, 2013 forming within the main crater at Mexico’s Popocatépetl after a week on continuous strong ash emissions and explosions. Image: CENAPRED.
Programming Note: I’ve now entered summer crunch time. Between lab time and field work with my students over the next month along with my own projects and manuscripts that need to move forward before the start of the next school year, I am going to be busy with a capitol B. I’ve going to try to keep up with posts as events occur, but I can’t guarantee that I can update as quickly and frequently as I normally do, at least not until this stretch is over. Hopefully this helps dispel that myth that someone college faculty have the summer “off” … !
Onwards to the update!
As noted in this space last week, Popocatépetl has had an active week, to the point that a multitude of flights in/out of the international airport in Mexico City were cancelled. This huffing and puffing at Popocatépetl, with ash plumes reaching 3-4 km above the volcano, has prompted the elevation of the alert status to Yellow-Phase III. This means that the eruption at the volcano has moved from sporadic explosions (Phase II) to frequent small to intermediate explosions, usually caused by a dome collapse (that can generate pyroclastic flows). Tremor is almost constant at the volcano, along with constant emission of ash-and-steam from the summit vent.
An overflight of that vent on Sunday showed that a new lava dome has formed within the crater during the past week’s activity (see above), meaning a new sequence of dome growth (and eventual collapse) is in full swing. As magma rises up under the active vent, a plug of lava forms (as the lava dome). The pressure rises under the plug and it is eventually destroyed (either by collapse or explosion), leaving the magma underneath to feel the drop in pressure, prompting an explosive eruption. Once the vent is clear, new lava can begin to fill in the vent to form another new dome and the cycle continues.
This type of eruption is common at many arc-related volcanoes like Popocatepetl like Mount St. Helens, Soufriere Hills and Merapi. You can check out this USGS page on this same pattern that occurred at St. Helens after the catastrophic 1980 eruption or if you want to get cozy with a dome, check out this video of the dome at Mexico’s Colima taken in 2008 — rubbly piles of extruding lava within the main crater vent. The collapse of these domes can be one of the most dangerous and unpredictable events at a volcano as the extrusion of the dome isn’t particularly violent, but the collapse can generate large pyroclastic flows. A collapse of a dome at Unzen killed the famed volcanologists Maurice and Katia Krafft and Harry Glicken in 1991. The dome at Popocatepetl likely needs to get larger so it extends out of the crater at the summit vent (see above) before it can generate a large dome collapse pyroclastic flow, but all of this means that Popocatepetl needs to be taken seriously in this new phase of activity.
Small (but still hazardous) explosive eruptions from Kilauea in 2008 might require a tweaking of the Volcanic Explosivity Index (VEI). Image: HVO/USGS.
Much of the discussion of volcanic eruptions tends to center on the big ones — those monstrous eruptions that really capture everyone’s attention, potentially plunging parts of the planet into a cool spell that could last years. Those eruptions are relatively rare, coming a few times a decade for the smaller ones and a few times a century (or longer) for the real colossal blasts. It is true that those are important events to understand, especially because humanity will need to face life after a giant eruption like Tambora or Taupo someday in the future. However, all this focus on the enormous eruptions ends up leaving those “everyday” events in the cold. Even if they are small, they can have a profound effect on local areas, especially if they are places that are highly frequented by tourists.
Some background on the scale of volcanic eruptions: The Volcanic Explosivity Index (VEI; see below) was devised as a way compare eruptions (mainly explosive eruptions) much in the same way we compare earthquake magnitude using the Richter Scale. It was developed mainly to discuss eruptions that have an impact on global climate (that is, the big eruptions). The VEI is based on the volume of volcanic tephra (debris of explosive eruptions, like ash and bombs) that the eruption produces, so VEI 0-1 eruptions produce small amounts of tephra, only ~10,000 m3 (picture a cube with ~21.5 meter / 70 foot sides) while the VEI 7-8 eruptions produce a remarkable 1,000,000,000,000 m3 (take that cube and make it 10 km / 6.2 miles on each side). A VEI 7-8 eruption is actually 10 million times more productive than a VEI 0-1, however across the Holocene (the last 10,000 years), there have been only 6 eruptions that make it into into the heady VEI 7-8 territory while there have been at least 2215 VEI 0-1 eruptions that we know of. I emphasize this idea because a VEI 0-1 eruptions leaves little to be preserved in the geologic record — maybe a mere dusting of ash or a small lava flow — so this value is minimum value for these eruptions*.
The Volcanic Explosivity Index with volumes and terminology as currently defined. Image: Table 8 from Siebert et al. (2010), Volcanoes of the World, 3rd Edition.
That being said, if you’re standing near the vent of a 0-1 explosion, well, you can still get hurt or killed. Volcanic debris is heavy and it is thrown out of the vent at high speeds, so even a small explosion can be hazardous in places where people frequent. You might notice on the VEI that these very small explosive eruptions, those under 10,000 m3 fall into the VEI 0 category, which is described as “gentle”. That is because this is where the VEI breaks down and treats all eruptions that produce small volumes of tephra (remember, explosive debris) as effusive eruptions — that is, eruptions that produce lava flows. However, this is not the case in many places. The eruption of Mayon in May 2013 was a tiny phreatic (steam-driven) explosion that was likely VEI 0 but it killed 5 climbers who were near the vent when it occurred. That would hardly be considered as “gentle”.
Similarly, in 2008, Hawaii’s Kilauea produced a series of small explosive eruptions from the Halema’uma’u summit vent and this is detailed in a recent paper by Bruce Houghton and others in Geology. These explosions only produced 10-310 m3 of tephra, but due to the close proximity of the vent to tourist attractions and roads, they could have inflicted significant damage and injury if, let’s say, a tour bus was caught in their path. Thankfully this didn’t occur in 2008. These explosions were very small strombolian- or Hawaiian-style eruptions that would likely never have been noticed in the geologic record except for the fact that the Hawaii Volcano Observatory is right there, next to Halema’uma’u, to see it all happen. Clearly, these eruptions, although technically VEI 0, were not effusive or gentle. How can we handle such events?
A revised version of the VEI to account for very small but still explosive eruptions, as suggested by Houghton and others (2013). Image: Figure 5 from Houghton and others (2013).
Houghton and others (2013) suggest we might need to tweak that VEI scale to account for smaller explosive eruptions. However, we don’t want to disrupt the definitions for VEI 1-8, so they suggest we project downward, so the 2008 eruptions at Kilauea would be VEI -2 to -4 (see right): clearly explosive, but small. The use of “gentle” and “effusive” would be jettisoned from the VEI — after all, it is an explosivity index — and instead those small strombolian and Hawaiian eruptions that would be lumped into VEI 0 could be discussed with more clarity, which is important for developing volcanic hazard assessments for highly trafficked volcanic vistas like Kilauea or Tongariro. The next challenge would be figuring out how to compare the effusive (lava flow) eruptions with the explosive eruptions, which is more of an apples and oranges issue. However, by adding negative VEI values, we can give those small explosions a little more of their due.
* Sidenote: If you do a rough estimate of the total volume over the last 10,000 years of all the VEI 0-1 eruptions (assuming 10,000 m3 per eruption, which is likely a very loose estimate), the total volume still only adds up to roughly a VEI 2-3 eruption (something like Redoubt’s 2009 eruption).
Sheveluch volcano, Kamchatka, Russia – (AV & CultureVolcan – June 27 – 15:37 UTC)
KVERT report of June 26 : According to seismic data, strong ash explosions began from 19:10 UTC on June 26, and continued about 40 min. Probably ash plumes rose up to 33,000-39,400 (10-12 km) a.s.l. Ash plumes are extending to the SOUTH-WEST of the volcano. Ashfalls was in Klyuchi Village – about 02 mm red ash. Density clouds obscure the volcano at now.
Explosive-extrusive-effusive eruption of the volcano continues. Ash explosions up to 23,800 ft (10 km) a.s.l. could occur at any time. Ongoing activity could affect international and low-flying aircraft.
Ash falls at Klyuchi Village on June 26, 21:00-23:00 UTC – Courtesy and copyright – Yu. Demyanchuk – Institute of Volcanology and Seismology FEB RAS, KVERT
Ashfall in Lazo village – image courtesy and copyright vmdaily.ru – also thanks to http://laculturevolcan.blogspot.fr/ for pointing us
Veniaminof volcano, Alaska update – (GV – June 10 10:39 UTC)
At daylight the activity cloud can well be seen on the FAA webcam at Perryville. The image below dates from 05:22 Local time (=13:22 UTC).
FAA image
Veniaminof volcano, Alaska alert increase – (GV – June 10 10:39 UTC)
Over the past two days, AVO has detected gradually increasing seismic tremor beneath Veniaminof. They therefore raised the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory. Clear web-camera and satellite views currently show nothing unusual at the volcano. Similar seismic activity has been associated with ash emissions at Veniaminof in the past, most recently in 2005.
Yesterday seismic tremor continues at Veniaminof. Clear web camera views showed a steam plume over the past 24 hours, though it is difficult to see in daytime views. AVO has received no other reports of activity. Update at the time of writing : Activity continues like we can see on the webcam images below. A smoke plume (steam and/or ash is difficult to see) is visible on these webcam picture (Perryville NW).
The seismogram shows a serious earthquake a little after 8 UTC. This is a far out in the sea earthquake which has nothing to do with the volcano. This was the earthquake which is viewable on the seismogram.
Some history : The volcano was the site of a colossal (VEI 6) eruption around 1750 BC. This eruption left a large caldera. In modern times the volcano has had numerous small eruptions (over ten of them since 1930); these are located at a cinder cone in the middle of the caldera.
Veniaminof has one of the highest elevations of Alaskan volcanoes. Partly for this reason, it is covered by a glacier that fills most of the caldera. Because of the glacier and the caldera walls, there is the possibility of a major flood from a future glacier run.
The volcano during another activity period in 1984
