explosive eruption
eklemetti | July 22, 2008
Admittedly, this is only a brief report, but there are indications that Tungurahua in Ecuador might be heading into a new period of heightened activity. Over the last week or so, there has been increased seismicity, reports of "booming noises" and increased ash emissions from the volcano. Being one of the more active volcanoes in the Andes, it would be surprising if the new eruptions were very big, but instead we might expect more frequent moderate ash and pyroclastic eruptions. However, with this little information, it is hard to tell what might happen and I'll keep my eyes peeled for more…
eklemetti | July 22, 2008
There were a number of small explosive events at Soufriere Hills in Montserrat in the past few days. Small ash columns of ~5,000 feet were produced, likely caused by some degassing or interaction with water of the andesite dome at the top of the volcano. The director of the Montserrat Volcano Observatory says there is little concern for heightened activity. The volcano has been erupting off-and-on since 1995 and these eruptions are just part of the ebb-and-flow of this period of activity.
eklemetti | July 21, 2008
Just when you thought it was exciting enough in the Aleutians, word comes in that Cleveland Volcano is erupting as well. Cleveland is a very noisy volcano on Chuginadak Island, having last erupted in February (although it hasn't been updated on the GVP page). Aircraft have been warned about both eruptions in the Alaskan island chain. Along with the eruption of Okmok Caldera, the AVO has their hands full watching these volcanoes. The latest on Okmok has a 24,000 foot ash column continuing to be emitted from the new vent.
eklemetti | July 21, 2008
The latest eruption at Llaima is beginning to slow down according to Chilean state geologist, Hugo Moreno. The volcano has been erupting for most of the month, forcing limited evacuations. The eruption has (so far) produced lava flows, ash falls and some bombs thrown from the crater. However, the SERNAGEOMIN is keeping the "red alert" on Llaima.
With persistently active volcanoes like Llaima, it is not surprising that they see multiple eruptive periods during each year. In a sense, this is actually better for the people living around the volcano because the more often the volcano erupts, the…
eklemetti | July 20, 2008
It has been a while since we've seen a Chaiten update, but today there is a report that LanChile has had to cancel flights to Puerto Montt due to ash from the volcano. Chaiten has been erupting since early May, so now we're almost 2 1/2 months into the eruption - quite a feat for such a large eruption! The report also mentions that some residents of the town of Chaiten have been able to visit their homes to collect belonging and the government might just try to rebuild the town in an entirely new location. The USGS plans to send geologists to the volcano later in 2008 or early 2009 to survey…
eklemetti | July 20, 2008
I'm back from my conference and will hopefully be getting back to a regular schedule!Â
In the meantime, the biggest news is still the eruption of Okmok Caldera in Alaska. The latest news has the eruption still going strong and the USGS predicting it will continues for potentially weeks to months. The eruption is apparently from a new vent on the caldera floor as well. Looks like the current eruption might be a VEI 4 (or thereabouts) eruption based on what I've heard from USGS scientists.Â
The largest hazard posed by Okmok right now is to air travel, this during a time when the Alaska…
eklemetti | July 15, 2008
Not really a "new eruption" as such, but the Geophysics Institute of Ecuador is reporting that Tungurahua, one of the most active volcanoes in South America, has been erupting ash and bombs as of late, along with showing signs of increased seismicity. Nothing new for this tongue-twister of a volcano as it has been erupting since 1999.
eklemetti | July 15, 2008Here's a stunning shot of the current eruption at Okmok Caldera in Alaska (brought to us by National Geographic).
Personally, I think the best part is the fact that this was shot by an Alaska Airlines pilot! Talk about "to the right of the plane..." fodder.
eklemetti | July 14, 2008Sorry about the brevity of this update, but I'm exhausted.
From the Alaska Volcano Observatory (AVO):
At this time, based on AVO analysis of satellite data, ash is
continuing to erupt from a composite cinder and spatter cone called
Cone D in the eastern portion of the 6-mile wide caldera or crater of
Okmok. It appears that the eruption is very water-rich due to
interaction of rising magma with very shallow groundwater and
surficial water inside the caldera. We have few direct observations
into the caldera and details of the current event remain unknown.
The current activity differs in…
eklemetti | July 12, 2008
Okmok Caldera in Alaska's Aleutian Islands erupted today, sending an ash column to at least 30,000 feet. Very little news has been released about the eruption so far beyond this information about the eruption column and some bits about precursor seismicity. A number of flights to Unalaska Island were cancelled due to the eruption. I'll pass on more information when I get it.
Okmok is located near Dutch Harbor, Alaska and is a large shield volcano with two prominent calderas at the top. In fact, whenever I see pictures of the caldera, I am reminded of what Crater Lake (Oregon) might look…
eklemetti | July 11, 2008
Some news of a series of small eruptions at San Cristobal in Nicaragua. Ash from the small explosions drifted to a town near the volcano, however officials for Ineter in Nicaragua say that there is little chance of a large eruption.
San Cristobal is one of the seven active volcanoes in Nicaragua. It has a long record of small eruptions, with at least one every year in the 21st century (and beyond). The largest eruption in recent times was in 1999 that produced lahars and an explosive eruptions (landing us at VEI 2).
eklemetti | July 10, 2008
Llaima (Chile) is experiencing an increased tempo in its current eruption. The National Emergency Office in Chile is reporting that the eruption has begun to take a more explosive character, with pyroclastic material being shot hundreds of meters from the main vent. Although the officials have not changed the current status of the evacuation, which has been limited to 50 people closest to the volcano, they are pondering their next step if the week-old eruption continues to escalate.
eklemetti | July 4, 2008[wp_caption id="" align="alignnone" width="400" caption="Anak Krakatau"][/wp_caption]
Indonesia's Volcanology and Geological Disaster Mitigation Center of the Ministry of Energy and Mineral Resources (whew, that is a mouthful) has placed Anak Krakatau on high alert for increased activity. Tourists were warned not to climb on the volcanic island in the Sunda Straits that rises from the remnants of the famous 1883 eruption of Krakatau. Anak Krakatau formed within the caldera of the ancestral volcano and have been fairly active since the 1920's, producing incandescent bombs and small ash…
eklemetti | July 4, 2008[wp_caption id="" align="alignnone" width="360" caption="Llaima 2008"][/wp_caption]
The current eruption at Llaima in Chile is causing some concern about flooding in the Rio Calbuco near the volcano. The lava flows are melting snow on the volcano and this is being exacerbated by heavy rain in the area as well. The eruption seems to have waned some according to the governor of the region. This all follows the evacuations of people near the volcano and the red alert issued by the Chilean government. (The picture of Llaima is from the January 2008 eruption.)
eklemetti | July 2, 2008
There are some astounding new pictures of Chaiten in full eruption over at the Smithsonian Website. There pictures were released by the USGS/VDAP team and show a full eruption column coming from the new dome in the Chaiten caldera (see above and below). The dome itself looks giant, filling up a lot of the old caldera (the highlands around the edge of the dome itself). The eruption is almost the antithesis of the 2004-08 Mt. Saint Helens dome eruptions which has produced a minute dome filling the 1980 crater. This rhyolite dome is the first major rhyolite eruption in almost 100 years, so I…
eklemetti | June 26, 2008I found this picture on the SF Chronicle website and it speaks volumes about the destruction wreaked on Chaiten, Chile.
The ash has buried the town and what the ash hasn't damaged, the water and debris from the swelled river in the background have finished off. This is what volcanoes can do in the blink of an eye (geologically speaking).
eklemetti | June 25, 2008
Since the "surprise" eruption of Chaiten in southern Chile (still erupting away), I'm sure there has been a lot of talk about better monitoring and predictions for volcanic eruptions. Now, we don't know the full extent of the facts, but usually an eruption of the magnitude of Chaiten (VEI 6, i.e., BIG) don't just go off out of the blue. There are precursors, such as seismicity under the volcano, uplift of the land over the volcano (think of the bulge of Mt. Saint Helens prior to the 1980 eruption), increasing emissions of volcanic gases such as carbon dioxide or sulfur dioxide, increase in…
eklemetti | June 24, 2008
If Alaska wants to take a cue from Iceland, it might find itself with more power than it can use. That is, if the dreams of the Alaska Division of Oil and Gas come true. They are planning to lease land on Mt. Spurr and possibly Mt. Augustine for geothermal exploration. Both of these volcanoes are active, with Mt. Spurr erupting last in 1992 (famously almost taking out a KLM 747 due to volcanic ash EDIT: Oops, this was not Spurr in 1992, but Redoubt in 1989. Luckily, AVO knew to warn aviation about the Spurr eruption thanks to the lessons learned from the near disaster at Redoubt) and…
eklemetti | June 23, 2008
Things have quieted down on the volcano-news front lately. I did catch a report that Fuego (Guatemala) is having small explosions (stombolian eruptions; link in Spanish), producing small (100s m-tall) ash columns along with some throwing incandescent blocks 30-50 meters from the vent. Just the typical noises expected at an active volcano. In the meantime, you can check out the volcanic hazards information that the Guatemalan survey (INSIVUMEH) has posted on their website. I'm always a fan of a country trying to educate their citizens of the real dangers of volcanoes and how to prepare.
eklemetti | June 19, 2008
Just when you thought it was safe to go outside.
After apparently settling down a bit over the weekend, Chaiten has kicked it back up a notch. The latest reports say that two ash columns are active ... and that is about all we get for more news. Not surprisingly, most of the damage around the volcano has been done by flooding and/or lahars, thanks to the ash and debris-choked rivers like Rio Blanco. It also sounds like the SERNAGEOMIN is digging in for the long-haul, calling for the eruption to go on - to some degree - for months. This isn't too shocking considering the minor dome eruption…