volcano monitoring
eklemetti | March 25, 2009Image courtesy of AVO/USGS. Taken by Cyrus Read
Based on the current levels of seismicity over the past 36 hours, AVO has returned Redoubt to Orange/Watch status from Red/Warning. This doesn't mean that the eruption is over, just that things have settled down a bit. Flights to and from Anchorage have resumed as well. You can read the full statement here, but the take-home messages are:
AVO expects this to be like the 1989-1990 dome-building eruptions, although no new dome magma has been seen yet (mostly thanks to poor weather).
Dome collapse will likely generate pyroclastic flows with little…
eklemetti | March 25, 2009Its been a busy week for volcanoes between the headline capturing Tongan and Alaska eruptions. Catch up on what you might have missed with the latest SI/USGS Weekly Volcano Report (for 3/18-3/24). Highlights (beyond Hunga Tonga Hunga Ha'apai and Redoubt) include:
Galeras, Colombia has settled down a bit
More block-and-ash flows from the two dome complexes growing at Chaiten, Chile
Strombolian eruptions at Mt. Etna, Italy
Plumes of steam and minor ash were reported from Popocatépetl, Mexico
A small lahar was seen at Tungurahua, Ecuador
Ash plumes and incandescent tephra explosions were…
eklemetti | March 25, 2009Redoubt seems to be setting its pattern for this part of the new eruptive period. There was another small explosion this morning that produced at 15,000 foot / 5,000 meter ash column that moved to the NNW. The seismicity has settled down since the early morning eruption today (3/25) as well.
These types of explosions producing plinian and subplinian eruption clouds that will likely lead to dome building - the same pattern seen at Mt. Saint Helens in 2004-2008 and the previous Redoubt eruptions in 1989-1990. These explosions, producing ash columns that reach tens of thousands feet, will likely…
eklemetti | March 24, 2009Mauna Loa fire fountains in 1984
For those of you looking for some non-Redoubt-related volcano news, you can take a look at the 25th anniversary of the last eruption at Mauna Loa (there is some nice video footage provided by KHNL if you follow the link). By no means is this volcano "dormant", but rather this is a typical lull in activity at the Hawaiian shield volcano. Its neighbor, Kilauea, has been erupting for decades, but the last major eruption at Mauna Loa was in 1984, when the volcano sent lava downslope with 3,000 feet of Hilo, moving 15 miles in a few days. Monitoring at Mauna Loa…
eklemetti | March 24, 2009Image by AVO/USGS/Game McGimsey, March 23, 2009
Redoubt has simmered down some today with no new eruptions since yesterday evening. AVO's field crew not only fixed the Hut webcam, but also spotted massive lahar deposits (see above) in the Drift River valley that traveled 35 kilometers downstream and have officials on local and national levels worried about the Drift River Oil Terminal. Funny, it sounds so familiar somehow? As usual, an ounce of planning and thought about locating an oil terminal at the foot of an active volcano would have prevented about 10 tons of problems now.
AVO will be…
eklemetti | March 24, 2009Image courtesy of AVO/USGS
AVO has posted a series of images taken around Redoubt and around the Cook Inlet since the new eruptions started the night of March 22nd. You can begin to see the extent of the ash fall, what the explosions have done to the Drift Glacier and the new deposits in the Drift River valley. Most of the images show a lot of meltwater mudflows and tephra deposits on the slopes of the volcano. They've also added images from satellite and radar sources that show the initial dispersal of ash from the eruptions throughout the area north of Redoubt.
Eruptions reader Akira…
eklemetti | March 23, 2009The Hut webcam at Redoubt that has a great view of the hydrothermal vents near the 1989-90 domes - and the area where the current eruption is likely to be sourced - is back online. So far, we can see what looks like lahar deposits on the lower left-hand flanks of the volcano in the stream channels (likely formed by the melting of the Drift Glacier) and ash deposits all over the snow. Also, depending on the light and clouds, you can definitely see an ash column coming from the volcano.
Also, AVO is reporting that at 7:41 PM (Alaska time), a new ash column was spotted on radar reaching 60,000…
eklemetti | March 23, 2009
The Anchorage Daily News has a report that 16 Alaskan representatives got stuck in Anchorage after the eruption started. They were headed to Juneau to vote on Alaska accepting stimulus money ("volcano monitoring" anyone?), but they were on one of the many flights canceled by Alaska Airlines today due to the ash. ADN also have reports of an "ash out" in the coastal town of Skwentna.
AVO is currently reporting that ash doesn't appear on the current radar maps in the Cook Inlet and there are no reports of new ash fall. This suggests that the ash is either staying below 13,000 feet / 4,000…
eklemetti | March 23, 2009
Redoubt on 3/15/2009, from Eagle River overlooking Anchorage. Photo courtesy of Calvin Hall
I'm breaking this out of the comments of the "Redoubt Erupts!" post just to keep things up-to-date.
As of now, we know:
At least 5 explosions have occurred as part of the eruption
Ash has drifted to the NNE and W - both as seen on radar and as reports of ash falling in Skwentna and the Chuitna area - and so far missing populated areas (see above)
The ash cloud is believe to have reached as high as 50,000 feet/15,000 meters - prompting an aviation warning/restrictions and cancellation of flights out…
eklemetti | March 23, 2009Mt. 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…
eklemetti | March 22, 2009Seismicity 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.)
eklemetti | March 20, 2009
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…
eklemetti | March 19, 2009Mixing volcanoes and oceans seem to always produce exciting results. Whether it is something as simple as the ocean entry of a lava to something as impressive as a new island emerging, formed by volcanic eruption. Back in the 1960s, a previous unknown undersea volcano off the coast of Iceland erupted to form the island of Surtsey. The signs of the impending eruption were captured from start to finish, with Icelandic fisherman noticing "boiling seas", then steam explosions, then ash eruptions and finally volcanic tephra that formed the island itself. This was followed by lava flows and…
sheril | March 19, 2009..about the undersea volcano that's been erupting over the last four days in the South Pacific!
What you see is smoke, steam, and ash shooting up thousands of feet near Tonga. And while this activity poses little threat to islanders right now, the image reminds me why I'm in favor of "something called 'volcano monitoring'," even if the Louisiana governor disagrees.
eklemetti | March 18, 2009Image 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…
eklemetti | March 18, 2009I probably won't comment too much on these, but if you need a rundown on every volcanic rumbling on the planet in a given week, nothing is better that the weekly reports compiled by the USGS/Smithsonian Global Volcanism Program. You can check them out both through the GVP website and as a convenient RSS feed.
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 16, 2009Oldonyo L'engai, Tanzania
As with most disasters, the best way to prevent a Katrina-like catastrophe is preparedness. The best successes in volcanic mitigation have been in places where the combination of monitoring, communications and practice fit together like so many legos in a set, allowing for a calm and orderly evacuation when the eruption, or signs of eruption, began (e.g., Rabaul in 1994). This is why it is always heartening to me to see articles about places trying to implement hazard mitigation plans for their volcanoes. Two examples are in the news today:
(1) Officials in…
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…