seismicity
eklemetti | January 31, 2009
The "eruption watch" continues at Redoubt ... Saturday revealed that things are getting hotter at the summit near the 1989/1990 dome (see picture above that made Redoubt famous in 1989). The overflight of the volcano revealed new holes in the summit glacial and a multitude of muddy streams formed from the meltwater. This area of very intense fumarolic activity is just below the 1989/1990 dome (~7,100 feet) and has been growing over the past few days. They also report an area at ~9,000 feet on the volcano that shows signs of ice collapse, indicating heat from underneath the snow and ice (…
eklemetti | January 31, 2009
The Anchorage Daily News has an excellent article today on the Drift River Oil Terminal, a depository for oil collected from the platforms in the Cook Inlet. This oil terminal stores at least 1,000,o00 barrels of oil (see article for why we're not sure) and sits, well, at the base of Redoubt (see map below from Anchorage Daily News) on the floodplain of the Drift River (~25 miles from the vent).Â
Now, this oil terminal was more-or-less destroyed during the last episode of volcanism at Redoubt twenty years ago when the terminal was wiped out by floods resulting from the eruptions. Not only…
eklemetti | January 30, 2009
I am surprised as anyone how the public has become captivated by this geologic drama unfolding at Redoubt. Headlines about the volcano are popping up everywhere from CNN to the MSNBC to Slashdot to Popular Science - yes, even the nerds are enthralled, which might be the reason that the AVO servers are overloaded today (and that Eruptions has set new records in visits each day for the last 4 days). The stories are pretty typical: everyone is preparing/panicking, the volcano might have a giant eruption, and so on. This is rapidly becoming the most eagerly anticipated (is that the right word…
eklemetti | January 25, 2009
Eruptions reader Ross was very right in pointing out that something is up at Redoubt. The Alaska Volcano Observatory has put Redoubt on orange alert for aviation and suggest that an eruption could occur with "hours to days". The most recent update from AVO says that a recent overflight of the volcano done this afternoon shows no evidence that an eruption has started, but steam and sulfur output has increased. Meanwhile, seismicity at the volcano is also well above background. In all, it sounds like the Aleutians might have yet another volcano erupting if these signs continue.
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 | December 9, 2008
The BBC is reporting today on a study published in Earth and Planetary Science Letters that attempts to establish a connection between large earthquakes and subsequent volcanic eruptions. The study is focussed on large Chilean earthquakes over the last 200 years (Chile has had some of the biggest, hitting M9 on the Richter Scale) and then examining the number of volcanic eruptions that followed. They find that activity increased in the year after the earthquakes. This suggests that many volcanoes might be "primed" to erupt and just need a catalyst like a large seismic event to promote…
eklemetti | December 5, 2008
The blasts and pyroclastic flow from earlier this week at Soufriere Hills in Montserrat were not the only show planned for the week, apparently. The volcano continues to erupt, with reports of continued ash and ballistic glowing bombs being erupted. These eruptions are the first major ones at Soufriere Hills in 6 months, but are apparently unique with no real precursors such as seismicity (well, none identified as of yet).
eklemetti | December 3, 2008
Just to keep everyone on their toes, Soufriere Hills on Montserrat in the West Indies erupted today. The eruption produced a number of explosions and a pyroclastic flow that originated from the west side of the lava dome at the summit of the volcano. However, the most interesting bit comes from the Montserrat Volcano Observatory (MVO) report I received this morning:
"The explosion happened without any warning. There was no precursory seismic activity."
Sounds like it could have been a dome collapse caused by a rapid release of gas/steam? The explosion apparently threw blocks as far as a…
eklemetti | November 22, 2008
Eruptions and earthquakes go hand-in-hand a lot of the time. It only makes sense as magma needs to move under the crust, causing movement (i.e., earthquakes). Additionally, any sort of explosions caused by the release of volatiles might cause earthquakes or even the collapse of an edifice (which in turn, shakes the earth).
So, it is not surprising that the current eruption at San Cristobal in Nicaragua has produced earthquakes. The reports are relatively lacking in details, but San Cristobal is a typical Central America stratovolcano that produces frequent Strombolian style eruptions, which…
eklemetti | November 5, 2008
In one of the most oddly worded articles I've seen from the BBC, a lava flow from Erta Ale an unidentified volcano in the Erte Ale range in Ethiopia has erupted a significant amount of lava. The headline states "Ethiopia volcano sets lava record", which is strange on multiple counts, but mostly because I'm not familiar with any "lava records", who might keep track of them and what, exactly, this "lava record" is. In fact, they don't even mention it in the article itself. They do, however, point out that lava from this eruption has covered 300 square kilometers, which is a decent chunk of…
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 | 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 25, 2008
If anyone has been watching the earthquakes worldwide today, you might have noticed that there have been three >M2.5 earthquakes in the Yellowstone Caldera today at depths <10 km. Not to say that it is anything, but just something to note.
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
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 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 14, 2008
This article sums up a lot of the events that led up to the Kasatochi (Alaska) eruption last week from the point of view of the biologists on the island itself right before it erupted. There are some great descriptions of the whole island shaking for 10 minutes, and they also offer some exciting new details such as this:
"Jeff Williams, a biologist for the maritime refuge, sailed by the island on the refuge boat the Tiglax and said the island has a new shape; what were steep cliffs rising from the ocean on the island's east and west sides now appear to be long, gradual slopes."
That would…
eklemetti | August 14, 2008
I'll be brief (as I'm in the middle of moving), but I did see a report that activity at Chaiten is increasing yet again. This seems like the operating mode for this volcano, with a waxing and waning of intensity, since the volcano started erupting on May 2. The latest report indicates renewed ash emissions producing an ash column that reaches ~20,000 feet (4,000 meters), with ash falling on nearby areas. There is also mention of some increased seismic activity at the Chilean caldera. The picture above shows the extent of the mobilized ash and volcanic debris that has wiped out much of the…