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 the system (i.e., eruption). Anchorage might call this a “near miss,” but Redoubt will erupt again, more likely sooner rather than later. As AVO puts in in their statement today:
It remains possible for unrest at the volcano to change rapidly, advancing from relatively low levels to eruption in time periods as short as 24 hours or less.
And that is why we need volcano monitoring, especially when volcanoes are so complex.
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.
As 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.
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 vents on the volcano were the most vigorous as has been seen so far. John Power from AVO did temper the expectations of activity:
“We do feel that the most likely outcome of the current activity of level will be a eruption at some point, although it is still always a possibility that it could die away…”
Currently, Redoubt seems to have quieted back down according to the latest report from AVO. The watch marches on.
Not 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.
Nothing 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.
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 will watch seismicity for signs of activity, or will this be a dedicated position that coordinates seismic, gas and deformation monitoring? The article doesn’t say much beyond seismographs and (vaguely) GPS. Nor does it mention what the seven new volcanoes are beyond Mt. Shirane and Mt. Norikura. However, I do give Japan credit for having such foresight when it comes to potential volcanic hazards.
One volcano that is already being constantly monitored is Mt. Asama, which has been erupting for over week. However, folks are already wondering when officials will say that Asama is “back to normal”. You can get a good idea of the ash dispersal from Asama with this excellent satellite image (above) from just after the January 21, 2009 eruption.
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 stations. AVO continues to monitor Redoubt 24 hours a day.
So, don’t get too excited about slightly elevated apparent seismicity over the weekend (and note, with the poor visibility, this would be a great weekend for Redoubt to decide to erupt).
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 activity, showing that most of the material is mobilized in that direction. It still amazes me that the oil terminal was ever allowed to be built in that location.
As for the current state of things at Redoubt, AVO reports that the seismicity is still going and things remain much the same as it has been for the past few weeks. Officials on the Kenai Peninsula are assuring residents that they’re ready for an eruption. At this pace, they might have months to prepare!