Vulkaanuitbarsting bedreigt grootste stad Alaska


Sarah Palin heeft als gouverneur van Alaska even andere zorgen aan haar hoofd dan de Amerikaanse Republikeinen uit de crisis te halen. Anchorage, de grootste stad van Alaska met zo'n 280.000 inwoners, wordt bedreigd door de uitbarsting van de vulkaan Mount Redoubt. Volgens geologen is er zoveel activiteit in de berg dat een uitbarsting de komende dagen mogelijk is. De vorige uitbarsting van Mount Redoubt dateert al van 19 jaar geleden.

Explosief
Het typische aan deze vulkaan is dat hij heel explosief kan uitbarsten en as tot 130 km hoog in de lucht kan spuwen. Bij andere vulkanen gaat de uitbarsting gepaard met een langzame lavastroom op de flank van de berg. Omdat gas probeert te ontsnappen maar geblokkeerd zit in Mount Redoubt, komt er een immense druk in de vulkaan.

Tips
Als de wind ongunstig staat bij een uitbarsting kan Anchorage een enorme aswolk over zich heen krijgen. Nu al krijgen de inwoners enkele tips: ze moeten bij een uitbarsting binnen blijven als dat enigszins mogelijk is. Als ze toch naar buiten gaan, moeten ze hun mond en gezicht beschermen. In de vulkanische as zitten kleine stukjes rots en glas.

1989
In december 1989 begon een liefst vijf maanden durende uitbarsting van deze berg van 3.048m. Internationale vluchten werden verstoord en de hele streek werd bedekt met een dikke aslaag. Hoewel Mount Doubt zo'n 160 km ten zuidwesten van Anchorage ligt, nemen de autoriteiten nu al heel wat voorzorgsmaatregelen.

_©Hln | Gewijzigd: 21 april 2017, 17:33 uur, door Joyce.s

Redoubt Volcano Latest Observations

Seismic unrest continues at Redoubt. Though seismic activity has diminished over the last few hours, it is still well above normal background levels. AVO continues to observe potential activity with seismic, satellite and radar data. The volcano has not erupted.

An AVO observation flight this afternoon reported no sign of ash emission, but observed significant steaming from a new melt depression at the mouth of the summit crater near the vent area of the 1989-90 eruption.

The Aviation Color Code remains at ORANGE and the Volcano Alert Level remains at WATCH.
Seismograaf:


_{Bron: AVO}

Will volcano blow? Expert waits, watches, ready to warn

It's 3 degrees and snowing outside the Alaska Volcano Observatory in Anchorage, but inside the operations center, things are heating up.

This is kind of the nerve center, if you will, says geologist Michelle Coombs, who is at the helm of a bank of video monitors showing readouts from sensors on Mount Redoubt, a volcano about 100 miles southwest of Anchorage. The sensors measure seismic activity on the volcano's summit. Scientists at the observatory combine that information with data gathered from daily airplane flights to the volcano to measure gases and try to figure out if and when Redoubt is going to blow.



We're seeing lots of little earthquakes right now, says Coombs. As that magma rises, it breaks rock as it gets to the surface, and it also it gives off gases, and that leads to the seismic activities were seeing now. When the magma, or molten rock, makes it to the surface, the volcano will erupt. A siren goes off, and one of the video monitors goes haywire. Is the mountain erupting? Learn more about Mount Redoubt?

"That's just a little alarm. There was just a little bit of increased seismic activity," Coombs says reassuringly. "It's a special kind of earthquake particular to volcanoes called a long-period earthquake. It has more to do with fluid and gases than with breaking rock."More...

_©CNN | Gewijzigd: 21 april 2017, 17:33 uur, door Joyce.s

Alaska's Mount Redoubt erupts

Mount Redoubt, a volcano in southern Alaska, began erupting late Sunday, according to the U.S. Geological Survey. The eruption, starting about 11:38 p.m. Sunday local time (2:38 a.m. Monday EDT), was obscured by darkness and snow. But the initial height of the eruption cloud was estimated at less than 20,000 feet above sea level, the USGS said.



With the eruption, mudflows were possible on the Drift and Crescent Rivers, and ashfall was likely near and downwind from the volcano, the USGS said. Earlier Sunday in Alaska, researchers had raised the monitoring status for the volcano, which was showing increased seismic activity.

"It is possible for unrest at the volcano to change rapidly, and seismic activity or other signs of unrest could escalate culminating in an eruption within days to weeks," a statement said at the time. Bill Burton, a geologist with the U.S. Geological Survey, said that, since January, there have been increases in seismic activity at Mount Redoubt followed by periods of quiet.

The 10,197-foot peak is about 100 miles southwest of Anchorage, the most populous city in Alaska.

_©CNN

Beruchte vulkaan in Alaska barst vier keer uit


In Alaska is de vulkaan Mt. Redoubt in vier explosies uitgebarsten. De berg spuwde een rookpluim ongeveer 1.500 meter hoog de lucht in. De vulkaan ligt dichtbij enkele belangrijke steden en volgens geologen was dit een vrij zware uitbarsting. In de steden is er voorlopig nog geen sprake van asneerslag. Gevaar is er niet, maar de geologen benadrukken dat het nog vroeg is.

Verse magma?
Sinds eind januari wordt Mt. Redoubt nauwkeurig in het oog gehouden uit vrees voor een nakende uitbarsting. Vorige week werd het alarmpeil voor het eerst verminderd. Geologen zullen nu onderzoeken of de stoom van deze uitbarsting wijst op verse magma of slechts de restanten van vorige uitbarstingen bevat.

KLM in problemen
Op 15 december 1989 veroorzaakte Mt. Redoubt bijna een ramp. De vulkaan stuurde toen een rookpluim ongeveer 2400 meter hoog de lucht in. Een vliegtuig van KLM raakte in de problemen toen de motoren uitvielen. Het toestel daalde drie kilometer vooraleer de bemanning de motoren weer aan de praat kreeg.

_©Hln | Gewijzigd: 21 april 2017, 17:34 uur, door Joyce.s

Alaska's Redoubt volcano erupts, more may follow

Alaska's Mount Redoubt volcano erupted with a burst of ash that rose more than 9 miles , and more eruptions are expected. The first blast occurred at 10:38 p.m. Pacific time on Sunday (0538 GMT Monday), the Alaska Volcano Observatory said, followed by four smaller eruptions.

The 10,197-foot (3,108-meter) volcano, located 106 miles southwest of Anchorage, Alaska's largest city, had been showing signs of a possible eruption for about two months. So far Anchorage has been untouched by harmful volcanic ash. There were five explosive events, said Tina Neal, a geologist at the Alaska Volcano Observatory, from around 10:30 p.m. on Sunday to 4:31 a.m. (0831 GMT) on Monday. Each lasted about 10 to 20 minutes.

Each event sent up an ash cloud as high as 50,000 and possibly 60,000 feet, Neal said. The observatory warned airlines to steer planes clear of the area. Alaska Air Group Inc, the state's leading carrier, said it had canceled 16 flights in and out of Anchorage by Monday morning. The bulk of the ash was blown at the 30,000-foot (9,150-meter) level, and is not reaching significantly populated areas, Neal said. It was blowing north-northeast and had been reported in the tiny community of Skwentna and possibly in Talkeetna.

The volcano is still restless, she said. We'll be watching it very closely. It is highly unstable still and further eruptions are likely. The latest round of seismic activity at Redoubt started in January, prompting the observatory to put it on an alert status and, at times, have staff on duty 24 hours a day. Residents of Anchorage and other communities in the region had prepared for an eruption by buying breathing masks for possible ash contamination and stocking up on food and water.

_©Reuters

Alaskans Brace for More Ash as Volcano Keeps Erupting

Rita Jackson said she was taking a sip of coffee when she tasted something funny on her lips ash. Alaska's Mount Redoubt's first cluster of eruptions in nearly 20 years a total of six were detected between Sunday night and Monday night sent a volcanic ash plume more than 9 miles into the air and down into nooks and crannies. Ash missed the state's largest city, but dusted small communities north of Anchorage. The National Weather Service had an ash advisory in effect until 5 a.m. Tuesday for the Susitna Valley. There were no reported injuries.



The wind took ash away from Anchorage, toward Willow and Talkeetna, near Mount McKinley, North America's largest mountain. Jackson, in Willow, was experiencing other effects, in addition to ruined coffee. My eyes are itching really bad, she said as she hurried to get out of a grocery store to drape protective blue tarps over a motorcycle, snowmobile and vehicles. The Alaska Volcano Observatory reports that the sixth eruption came at 7:41 p.m. Monday. The five earlier eruptions came late Sunday night into Monday morning.


_{National Weather Service doppler radar shows a large plume of ash during an eruption at Mt. Redoubt.}

Based on Mount Redoubt's historical patterns, this activity could continue for weeks or months, Interior Secretary Ken Salazar said during a teleconference Monday.More...

_©Foxnews | Gewijzigd: 21 april 2017, 17:35 uur, door Joyce.s

Nieuwe vulkaanuitbarsting in Alaska


De vulkaan Mount Redoubt in de Amerikaanse staat Alaska komt maar niet tot rust. Na een nieuwe eruptie werd een aswolk tot 20.000 meter hoog de lucht in geslingerd, meldt het vulkaanobservatorium in Alaska.

Luchthaven gesloten
Wegens het gevaar voor het luchtverkeer werd de luchthaven in Anchorage voorlopig gesloten. De exploitant hoopt dat vrijdag het verkeer weer kan hernemen.

Modderlawine
De eruptie heeft ook een modderlawine teweeggebracht, die in een rivier aan de voet van de vulkaan stroomde. De weerdienst riep de bevolking in de omgeving op wegens de asregen deuren en vensters gesloten te houden.

Kleine aardbevingen
Bij de uitbarsting van de vulkaan vorige zondag was de aswolk al eens 15.000 meter boven de zeespiegel uitgestegen. Amerikaanse geologen hadden sinds januari verschillende kleinere aardbevingen in de regio geregistreerd en met een uitbarsting rekening gehouden. De 3.100 meter hoge vulkaan ligt 160 kilometer ten zuidwesten van Anchorage, de grootste stad van Alaska, en had de afgelopen weken steeds weer as en rook gespuwd. In 1989 was de vulkaan vijf maanden actief.

_©Hln | Gewijzigd: 21 april 2017, 17:36 uur, door Joyce.s

Alaska Volcano Shoots Ash 25,000 Feet High

Alaska Observatory officials say Alaska's Mount Redoubt has spewed steam and ash up to 25,000 feet high. Alaska Volcano Observatory geophysicist John Power says the volcano had been spewing ash about 15,000 feet into the air before it erupted Tuesday afternoon. A broad layer of haze that could contain ash has extended from the Matanuska-Susitna Valley north of Anchorage to the Kenai Peninsula.



The eruption prompted Alaska Airlines to cancel 18 flights in and out of Anchorage, which is roughly 100 miles northeast of the volcano. The volcano has been active since March 23. The last time it erupted was during a four-month period in 1989-90.

_©Foxnews | Gewijzigd: 21 april 2017, 17:36 uur, door Joyce.s

Alaska's Mount Redoubt erupts again


The Mount Redoubt volcano in Alaska has had another large eruption after being relatively quiet for nearly a week. The Alaska Volcano Observatory in Anchorage says the volcano about 100 miles southwest of the city erupted early Saturday. The National Weather Service said radar indicated a plume of volcanic ash rose 50,000 feet into the sky, making this one of the largest eruptions since the volcano became active on March 22.

The ash cloud was drifting toward the southeast and there were reports of the fine, gritty ash falling in towns on the Kenai Peninsula.

_©MSNBC | Gewijzigd: 21 april 2017, 17:37 uur, door Joyce.s