speculation
Mt. Redoubt in March 2009, prior to erupting
At ~10:30 PM (Alaskan Time) last night, Mt. Redoubt erupted. AVO and the Anchorage VAAC issued a Red Alert for ash as high as 50,000 feet (15,000 meters) around the volcano. Information is scarce about the exact nature of the ash cloud because of the fact that the volcano erupted at night. The eruption has contained at least 5 large explosion and at least one of the seismometers at the volcano has stopped reported (RSO). An ashfall advisory has been issued by the Weather Service, with ash predicted to fall throughout the Susitna Valley (which…
Seismicity has increased dramatically at Redoubt in Alaska over the last 24 hours, so AVO has put the volcano back on Orange/ Watch status. They say the tremors being felt now could be signs to an impending eruption (days to weeks), especially after the other events of the past week. Stay tuned! (Pardon the briefness, I'm posting from my iPod.)
Now that people have been able to get a better look at the are about Hunga Tonga Hunga Ha'apai, we've been able to get a better idea of what sort of eruption occurred. The explosions and ash/tephra from the eruption have all but wiped out life on Hunga Ha'aapai, as the island contains one of the vents, while the other is only 100 meter off shore of the island - although the tephra erupted so far have joined the new vent and the island. You can clearly see ash mixing with the water around the island and the island itself has been blackened by the coating of ash. This is a classic volcanic…
Image from AVO Hut webcam for Redoubt
After an exciting few days ... well, OK ... after an exciting few hours on Sunday, AVO has decided to lower the alert level at Redoubt in Alaska to Yellow/Advisory. The alert level was lowered last week after seismicity at the volcano returned to normal after weeks of rumbling (at Orange/Watch status), but then we are all caught by surprise when a phreatic explosion occurred (and AVO returned the volcano to Orange). However, this didn't lead to a new period of heightened seismicity, so back to Yellow we go (even with elevated gas emissions and a nice…
Now that Redoubt has decided that Yellow/Advisory is not to its likely and has returned to an Orange/Watch status, I'll continue bringing new updates of the volcano has events unfold.
And nothing much has unfolded since the phreatic explosion that occurred on Sunday. The current state of the volcano, according to AVO, is minor seismic unrest and that is about it. They do offer some more details of the events on Sunday:
An AVO overflight Sunday witnessed activity from 11:30 AM until about 3:00 PM and was able to document ash emission from a new vent, just south of the 1990 lava dome and west…
Date: February 07, 2009 Image Creator: Bleick, Heather Image courtesy of AVO/USGS.
So much for my oh-so-eloquent eulogy for early 2009 activity at Redoubt.
AVO reports that it appears that the volcano has potentially erupted - or at least released a lot of steam and (possibly) ash.
Seismic activity at Redoubt has increased since about 13:00 AKDT and is continuing. An AVO observation flight reported that a steam and ash plume rose as high as 15,000 ft above sea level and produced minor ash fall on the upper south flank of Redoubt. Last reports are that the plume is now mainly steam.
Doesn't…
Two tidbits from New Zealand:
- A recent survey of volcanoes in the Kermadec Arc north of New Zealand suggest that there is abundant - and recent - undersea volcanism. Scientists from University of Washington (one of my former homes) and Southhampton University (UK) explored a number of submarines volcanoes including Rumble II West, Rumble III and Brothers, which are all located along the same arc of volcanoes as New Zealand's own White Island and Mt. Edgecumbe. What they found was a change in the shape of Rumble III (1.4 km below the sea surface) since the last survey in 2007 - the summit…
Folks have been suggesting that life on Earth started near volcanic vents for a long time now (and of course, some people don't buy it). Whether or not life sprung forth near hydrothermal vents, undersea black smokers or from the head of Zeus, it doesn't really change the fact that we find organisms living in these places today, expanding what we might consider "habitable" by leaps and bounds. Case and point, researchers from CU-Boulder have recently found a community of micro-organisms happily living near the summit of Volcán Socompa (above) in Chile in the hydrothermal vents. Now, having…
Count this as your mini-update for Redoubt, with the news being no news. Even AVO seems a little bored with Redoubt lately (not to say they aren't watching it as vigilantly as ever) as their last three updates have been exactly the same:
Redoubt volcano has not erupted. Seismicity is low, but above background levels and consists mainly of small discrete earthquakes. Night has fallen and no image is visible in the webcam.
However, down the road (arc-wise) in the Aleutians, AVO has raised the alert level at Okmok Caldera. New volcanic tremors were felt yesterday at Okmok, averaging about one…
The Redoubt watch is now been going for well over a month and this is how quickly things can change when monitoring volcanoes. The headline in my volcano RSS, when I saw it said:
"Redoubt quiets after weeks of activity, though eruption still possible"
By the time I clicked on the link, the headline for the KTUU TV article became:
"Redoubt steaming at strongest level, seismic activity calms"
The seismic event refered to happened yesterday afternoon (Alaska time) and the volcano rumbled for about an hour, getting picked up by seismometers all around the Cook Inlet. They also mention that steam…
The people who remain in Chaiten face the potential for a devasting pyroclastic flow, so says Jorge Muñoz of the SERNAGEOMIN in Chile. The volcano is still producing large ash columns on Tuesday and a flyover of the dome forming inside the caldera has lead to the concern that a collapse on a larger scale than those seen last week could wipe out the town for good.
The government hopes news like this from volcanologists might convince the last remaining residents of Chaiten to leave, but no indication of this has come to pass. In fact, things sound like they're getting heated in the fight…
Jonathan Castro has reminded me that I need a refresher on the proper terminology for ash columns related to volcanic eruptions. It is very easy to start mincing words and using them inappropriately - and that is the sort of sloppy reporting and discussion I am trying to avoid.
So, to refresh my (and our) memory on ash clouds and how to classify them, we can go back to one of the indispensable textbooks on volcanology, Cas and Wright's Volcanic Successions. The classification scheme they provide is summarized in the figure above. It shows the heights of various eruption columns and the…
UPDATE 2/19/2009 9:45 AM: Well, it seems that my hunch was at least partially right. Reuters (and Paula Narvaez, special envoy to the Chilean president) is calling the eruption as result of "what appeared to be a partial collapse of its cone."Â So, we might have seen the oversteepening of the dome growing in the Chaiten caldera that lead to a collapse, producing (likely) a pyroclastic flow and either an accompanying plinian eruption as the pressure was released or an ash column associated with the pyroclastic flow itself. Now, I might not take Reuters word for it, but it makes sense…
We've now had three weeks of waiting for Redoubt, and all we have to show for it is steam, seismicity and lots and lots of press. As of today, Redoubt continues with the same: elevated seismicity, constant monitoring, think it will erupt.
Current status from AVO:
Redoubt Volcano has not erupted. Elevated seismicity is continuing, dominated by ongoing volcanic tremor and occasional small earthquakes. A storm system is moving across the Redoubt area at present, which will make for poor viewing conditions today. Associated winds are causing a small increase in seismic amplitudes on some seismic…
Is the volcano just toying with us?
After yesterday's steam plume (woo.), Redoubt was relatively normal today, albeit still at the heightened state of readiness. However, the steam plume has waned today compared to yesterday.
Now, whether this is actually a signal that the magma is not rising up into the volcano as rapidly as before or this is just the quiet before the storm is anyone's guess. This very well could be like the 2004-08 Saint Helens episode that ended up being fairly benign with only passive eruption (if there is such a thing) of dome material (hat tip to Boris for bringing up…
Guess what?
Still rumbling, still steaming, but still no eruption.
I'll put money on the idea that Redoubt will erupt tomorrow, when I have jury duty.
Just to keep us appraised of the situation at ever-steaming-and-shaking Redoubt:
From AVO (2/6/2009 11:05 AM)
Unrest at Redoubt Volcano continues.Â
After the tremor episodes of yesterday, seismic activity has remained slightly elevated relative to the last few days.Â
The volcano has not erupted.
That is about it. A few quick hits about Redoubt (as the world waits) include an article on potential redirected air traffic if the volcano erupts, an update mentioning that if the snow is falling during an eruption, radar won't pick up the ash until its at 15-20,ooo feet , how British Columbia is…
Bored with waiting for Redoubt to erupt? Well, Nevado del Huila in Colombia looks like it is also on the eruption watch list. A fly-over of Huila performed by Colombian officials (unclear from the article if it was done by National Emergency Management or INGEOMINAS) revealed a large lava dome growing in the crater, suggesting that an eruption might follow considering all the lava being extruded. This eruption might come in the form of an explosion caused by the collapse of this lava done - the collapse itself could generate a pyroclastic flow and the release of pressure on the underlying…
UPDATE 2/1/09 5:02 PM Pacific: Indeed, Asama did erupt today. The eruption was relatively small, throwing ballistic clasts up to 1 kilometer from the vent and ash into the outskirts of Tokyo.
Redoubt in Alaska has dominated the volcano news as of late, but it is clearly not the only volcano on Earth that is showing signs of eruption right now. The Meteorological Agency in Japan has just raises the alert level at Mt. Asama and warn that the volcano could erupt in the next "two days". Asama is ~150 kilometers from Tokyo and is very active (see above), having last erupted in September 2008. The…
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 (…