Stratovolcano
eklemetti | October 7, 2008
Nevado del Huila in Colombia continues to keep officials in the southeast region of the country on their toes as they wait to see what the volcano might do. There was increased seismicity over the weekend according to Jair Cardoso of the Attention, Prevention and Disasters Committee, along with minor steam and ash emissions. The Colombian geological survey, INGEOMINAS, will be sending experts (including Marta Calvache and Cesar Eduardo Lopez) to examine the current state of the volcano and try to decipher what state the magmatic system is in: ready to erupt or just gurgling away.Â
(Of…
eklemetti | October 6, 2008
There are a few brief reports of a minor eruption at Soputan in Indonesia. The reports from the Associated Press mention a small eruption column that reached ~1,000 meters and was accompanied by ash fall and explosions. From the sound of it, the eruption(s) are minor Strombolian types, common at arc stratovolcanoes like Soputan. Indonesia officials have warned people to watch for potential lava extrusion that might follow these explosive, possible "throat-clearing" blasts. Soputan was reported to have erupted earlier this year and has erupted frequently over the last decade.
eklemetti | October 4, 2008
Finally, after a rather quiet week, we have news that yet another Aleutian volcano is showing signs of potential activity. Redoubt Volcano was seen steaming away in a recent flight over the stratovolcano. When combined with reports of "booming noises" and the scent of sulfur it all points towards increased chance of eruption. However, AVO points out that they have not seen any increase in seismicity at Redoubt so far, making it difficult to predict exactly what the future will bring for the volcano. The volcano last erupted in 1990 and an eruption in 1989Â (above)Â produced a VEI 3 blast…
eklemetti | September 26, 2008
Shiveluch in Kamchatka experience a small eruption today. Russian authorities reported a ~4,500 meter ash column with associated local earthquakes, likely related to the eruption. In the same article, both Karymsky and Klyuchevskaya Sopka (also known as Kliuchevskoi) are erupting or showing signs of increased activity.
Shiveluch is one of the many active volcanoes along the Kamchatkan arc that is on the far eastern side of Russia. It has been continuously erupting since 1999, mostly in the form of small explosions, pyroclastic flows and lava flows/domes - your typical arc volcano.
eklemetti | September 18, 2008
Ruapehu is a noisy volcano, showing signs of eruptions on a yearly basis. It is also a potentially very hazardous volcano as it produces abundant lahars and has the capacity to generate a catastrophic lahar if the crater lake at the summit were to be breached by an eruption. This is why Ruapehu is one of the most closely watched volcanoes in the world, with all of its vitals being monitored on a daily basis. GNS Science in New Zealand is reporting that Ruapehu is headed into a new heating cycle, citing the increase in lake water temperature from 16 to 22C since August - and that seems like…
eklemetti | September 16, 2008
It is always fun to me when we discover that a volcano long considered dormant or extinct has seen activity in the recent past. I bring this up because Mount Nantai in Japan, a volcano that was considered to have last erupted over 10,000 to 20,000 years ago (if not longer) looks to have actually erupted as recently as 7,000 years ago. This might not seem like a big different to some folks, but this definitely puts the volcano in the "active" category if this date turns out to be accurate. The volcano looks to have had a number of explosive ash and pumice eruptions along with some dacite lava…
eklemetti | September 16, 2008
For those of us who track volcanoes and the hazards they present, the general consensus is that Mount Vesuvius in Italy is probably the most dangerous volcano in the world today. This is not because it is the biggest or most powerful, but because it is located on the outskirts of Naples, Italy, a city with over 2 million inhabitants (including the surrounding area). Evacuating such an area quickly and efficiently during a time of crisis might be, well, impossible. We know that Vesuvius can be destructive - just look at the fact that much of the Naples area is built on the deposits of the…
eklemetti | September 16, 2008
After the news of a sizable earthquake under Nevado del Huila, we can add Nevado del Ruiz to the list of volcanoes that have been shaken up recently. There was a M5.7 earthquake underneath Ruiz on Saturday (9/13), which is a pretty significant event. However, the earthquake was located at over 100 km depth, so likely it is not related to any magma movement at Ruiz. I will keep my eyes open for any reports of increasing unrest at Ruiz and at Huila in the coming days.
eklemetti | September 11, 2008
(Note: Yes, I am posting when I said I wouldn't, but I felt I needed to post about Colombia).
Colombian authorities are evacuating the area around Nevada del Huila after increased seismicity suggests that the volcano will erupt soon. There have been over 700 earthquakes - many of which are clearly related to moving magma - over the last week or so, indicating that Huila might be entering a new period of eruption.
One thing to note: The article I've linked to mentions an avalanche at Huila that was related to an eruption in 1994. I can't find any evidence that there was any volcanic activity…
eklemetti | September 2, 2008
Whether this is a coincidence or not, I thought I'd mention a report of an earthquake near the crater of Nevado del Huila in Colombia. The earthquake is reported as a magnitude 4.6Â and at a depth of 20 km (although that is only a rough estimate), indicating that magma might be moving up the conduit system under the volcano - or that it might be just coincidental seismicity in a seismically active area. However, Huila had recently become active for the first time in 500 years, so this could be a sign of new activity to come.
eklemetti | September 2, 2008
Two volcanoes on the island of Luzon look like they might be primed for activity, at least according to PHILVOLCS, the Philippine Institute of Volcanology and Seismology. Both Mayon and Taal (above) are showing signs of increased seismicity. Only Mayon is actively steaming right now and the volcano had a mild ash eruption on August 10 as well. Officials in the Philippines have both volcanoes on Alert Level 1 (potential activity).
Taal is actually part of a bigger system that occupies a 15 by 20 km caldera. The island where most historic activity has occurred is made up of a series of…
eklemetti | August 19, 2008
I will be away from Eruptions for the next 2 weeks or so. I won't be on vacation, I will actually be out on volcanoes themselves doing some much-needed fieldwork. It is a three volcano tour, starting with a trip to Lassen Peak to get a guided view with Michael Clynne of the USGS (the world expert on the volcano, the last Cascade volcano to erupt other than Saint Helens).
Then follows a trip to Mt. Hood with Adam Kent from Oregon State (my doctoral alma mater) in Oregon to sample some of the youngest flows that are only a few hundred years old. Geologists from Oregon DOGAMI (Department of…
eklemetti | August 13, 2008
NASA posted a nice image of the ash plume from the current eruption at Kasatochi (Alaska) showing the brown/grey ash mixing with white clouds over the Pacific. Not much else to report on the eruption other than that AVOÂ reported that seismicity remained low from August 10-12.
eklemetti | August 11, 2008
The current eruption at Kasatochi is causing a lot of flight cancellations for flights from Alaska to points in the continental US. The ash is swirling its way around the Aleutians along flight lanes (see above), with the ash drifting southeast over the Alaska Panhandle and could hamper air travel in Alaska and Canada for days according to the USGS (although Alaska Air says it might start flying again later today). As for the eruption itself, not much new news beyond the initial impression that the volcano went from quiet to explosively erupting to produce at 35,000 foot (~10,000 meter) ash…
eklemetti | August 10, 2008
Mayon, a volcano in the Philippines, is on watch for an eruption after experiencing small explosions. Philvolcs, (short for the Philippine Institute of Volcanology and Seismology), reports a small ash emission - ~200 feet - but they feel that there isn't an imminent threat of an eruption. Mayon is an relatively active volcano in the Philippines, last erupting in 2006 and is well known for its prototypical conical volcano shape (see above).
eklemetti | August 9, 2008
The folks up in Alaska have a lot to watch these days in the Aleutians, with three volcanoes erupting right now. Just a quick update on the current activity:
Â
Kasatochi: The eruption that started Thursday and produced 45,000 foot ash columns has quieted by Saturday, but there are still moderate (M=5) earthquakes being recorded near the island (above, before eruption).
Okmok: Ash from the month-long eruption is falling on islands near the caldera.
Cleveland: Activity at Cleveland has quieted to the point that no ash column was spotted on Saturday.
eklemetti | August 8, 2008
Just a quick update if you haven't been following the discussion: Kasatochi volcano in the Aleutians is now listed in "Red Alert" as it is erupting (see image above). Not many details beyond the typical description of ash columns, in this case reaching 45,000 feet, which is a pretty decent height. The Coast Guard warns of pumice rafts from the eruption, but it is hard to tell if it because they exist, or that it is just the generic warning for any eruption at sea. The two USFS biologists were evacuated before the eruption.
Edit 8/8/08: I'll add a link to the official USGS Press Release on…
eklemetti | August 7, 2008
The Okmok Caldera eruption is still going on, almost a month after it started. The latest USGS/SI Weekly Report states:Â
Â
Strong volcanic tremor on 2 August prompted AVO  to raise the Volcano Alert Level to Warning and the Aviation Color Code to Red. Cloudy conditions prevented satellite observations. Later that day, AVO geologists in the area reported that ash-and-steam plumes rose to minimum altitude of 6.1 km (20,000 ft) a.s.l. The seismicity decreased and the Volcano Alert Level was lowered to Watch and the Aviation Color Code was lowered to Orange. Observers in Ft. Glenn on Umnak…
eklemetti | August 7, 2008
Finally, in a very slow week for volcano news, we find a report from the Alaska Volcano Observatory about concerns of another eruption in the state. Currently, both Okmok and Cleveland are erupting, and now AVO has issued a warning about Kasatochi Volcano on the island of the same name (~100 kilometers east of Adak, roughly near 175W on the map above). The volcano is the island - more or less - and any people on the small island are being evacuated due to increased seismic activity underneath the volcano/island.
Not much is known about the eruptive activity at Kasatochi. The volcano does…
eklemetti | August 5, 2008Â
Not much news in the world of volcanoes this week so far. Must be the mid-summer lull in activity as the northern hemisphere heats up (just kidding!) Anyway, I thought I would post a picture of a recently erupting volcano that a friend of mine shared with me. This shot (above, picture by Arkadiy Groshev) was taken on July 25 of this year as Karymsky volcano in Kamchatka was erupting. The volcano emitted ash for ~1 hour that day and it almost seems like a volcano-as-tourist-attraction type of eruption! The group in the picture is the PIRE (Partnership for Volcanological Research and…