seismicity
eklemetti | March 18, 2009
The eruption of Hunga Tonga Hunga Ha'apai volcano in Tonga looks to be a big one. Keleti Mafi, head of the Tongan geological service, calls this "a very significant eruption, on quite a large scale", which is no surprise considering some of the spectacular picture we saw of the eruption yesterday. In fact, the eruption is big enough that it has disrupted air traffic over Tonga, as Air New Zealand has issued a warning about the ash column - an ash column that has reached over 15,000 meters/50,000 feet! Luckily for the residents of Tongatapu, a mere 10 kilometers 50 km to the southwest SSE…
eklemetti | March 17, 2009
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…
eklemetti | March 15, 2009Date: 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…
eklemetti | March 10, 2009
AVO has officially downgraded the status at Redoubt from "Watch" (orange) to "Advisory" (yellow). The seismicity at the volcano has dropped off for the last couple weeks and signs that an eruption was imminent have waned. This, again, shows the difficulty in trying to predict the behavior of a volcano. All the signs were there at Redoubt - increased seismicity, increased heat flow at the summit (seen as melting ice and increased fumarolic output), increased volcanic gases (CO2 and SO2) - but as of right now, it seems like these signs only pointed to magma moving up the system, but not out of…
eklemetti | March 3, 2009
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…
eklemetti | February 28, 2009As there has been a lot of chatter about the goings-on at Redoubt, I thought I'd post the latest AVO update (3:35 PM):
Redoubt volcano has not erupted. Seismicity is dominated by small discrete earthquakes and tremor remains at the diminished levels of the past two days. Webcam images are now clear and show no change in the volcano.
Nothing doing. In fact, seems quieter than it has been in the last few weeks.
eklemetti | February 26, 2009The 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…
eklemetti | February 24, 2009Not much new to report with Redoubt except that folks in Alaska are getting, well, a little punchy.
AVO currently reports (7:12 AM):
Volcanic tremor and occasional discrete earthquakes continue at Redoubt. Since 00:00 local time on 2/24, tremor amplitude at nearby stations has gradually increased, and the number of small earthquakes on nearby stations has increased slightly.
Redoubt isn't exactly making us volcanologists look too good lately. That is the nature of the beast, I suppose.
eklemetti | February 23, 2009Nothing much to report on the Redoubt front except more of the same. The latest report from AVO says (6:44 AM):
Redoubt Volcano has not erupted. Volcanic tremor and intermittent discrete earthquakes continue. Data for the past few hours (since 00:00 AST on 2/23) has consisted almost entirely of low-level tremor, with few discrete earthquakes.
So, it seems that Redoubt continues on its holding pattern. In other fronts, the Anchorage Daily News is running a good synopsis of the monitoring AVO does on volcanoes in the Aleutian chain in Alaska. More updates as seen fit.
eklemetti | February 18, 2009
I found this little press release that doesn't have a huge amount of information, but is interesting nevertheless. The Coordinating Committee for Prediction of Volcanic Eruptions of Japan (nice name) is putting seven volcanoes on "24/7" monitoring. That sounds like we might see a lot of eruptions in Japan soon ... except that their rationale was that these volcanoes "are likely to affect public life by erupting or becoming active in the coming 100 years". That is quite the window of eruptive opportunity! The question is what exactly "24/7" monitoring - does this mean that someone/something…
eklemetti | February 18, 2009Not much to add to the Redoubt Watch this week. The volcano continuing to experience increased seismicity and AVO is watching it closely. Sounds like we'll be doing the same for the time being.
eklemetti | February 13, 2009We'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…
eklemetti | February 11, 2009The NASA Earth Observatory website posted this great image of Redoubt taken from Landsat images in 2000.
You can see a few neat things. The main thing I notice is that the Drift River Oil Terminal is in about the worst place you could put an oil terminal near a volcano like Redoubt. All the material from recent eruptions at Redoubt get focused down into the Drift River, which then heads off into the Cook Inlet via the Drift River flood plain (upper right hand side of the image). When this image was taken, the Drift River is still grey with volcanigenic material even 10 years after the last…
eklemetti | February 9, 2009Jury duty is done, so here is a little update.
Redoubt is puffing away, producing a more prominent steam plume than it has over the last week (but that may be more weather-related than magma-related.) Beyond that, the volcanic gases keep coming and the earthquakes keep coming.
eklemetti | February 6, 2009Just 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…
eklemetti | February 5, 2009For all you Redoubt vigil holders...
According to AVO at ~12:30 (2/5/09):
Starting at 11:18 AKST (20:18 UTC), a burst of more intense seismic tremor occurred. This episode lasted for about 4 minutes and was the most most energetic since January 30. Radar and pilot observations confirm our analysis that no eruption occurred.
eklemetti | February 5, 2009
A week ago, if you asked around, I'm sure most people would have thought Redoubt would have erupted by now considering all the seismicity and melting that was seen at the end of last week. However, volcanology is not an exact science, and here we are continuing to watch Redoubt tease us with signs of pending activity. New holes have appeared in the snow that caps the volcano, the seismicity continues and the volcano is still spewing sulfur dioxide, carbon dioxide and hydrogen sulfide - all signs that magma is intruding the volcanic edifice. However, as on this morning (2/5/2009), the volcano…
eklemetti | February 3, 2009
Redoubt (above) is definitely taking its time. After catching everyone's attention last week with seismic activity, melting of its snow cap and increased gas emissions, the volcano is still, well, doing all those things, but not erupting. AVO's update are beginning to sound like a broken record:
"(2/3/09 04:10) Unrest at Redoubt Volcano is continuing with elevated seismicity well above background levels. The volcano has not erupted. A gas/observation overflight yesterday reported continued changes in the summit glaciers indicative of heating of the summit area. Photos from both the…
eklemetti | February 2, 2009
Mt. Asama near Tokyo did, in fact, erupt within the "two day" window predicted by the Meteorological Agency of Japan. The reports this morning put the ash column at ~2,000 meters (~6-7,000 feet), so relatively small, but big enough to dust parts of Tokyo (~145 km away) with ash. No evacuations are planned for the area around Asama, but people who live within 4 km of the volcano are to "take caution".Â
There are also new reports that Mt. Sakurajima in southern Japan erupted yesterday. Block were thrown up to a few kilometers from the volcano. The article suggests that ash spread as far as…
eklemetti | February 1, 2009
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…