Alaska volcano emits plume of ash
Friday 30 December 2011
A volcano on Alaska's Aleutian Islands sent up an ash cloud today which prompted scientists to increase the alert level for commercial air traffic.
The Alaska Volcano Observatory said satellite images showed the Cleveland Volcano had spewed ash 4,572m into the air in a cloud which moved east-southeast. US Geological Survey scientist-in-charge John Power called it a small explosion.
"It's not expected to cause a disruption to big international air carriers," he said.
But the event drew strong interest from airlines.
"Any time you put an ash cloud up into the atmosphere, the airlines, the air carriers, air freight companies - it's a major concern," Mr Power said.
The ash cloud was significant enough to raise the alert level from yellow, representing elevated unrest, to orange, representing an increased potential of eruption, or an eruption under way with minor ash emissions or no emissions.
Cleveland Mountain is a 1,729m peak on uninhabited Chuginadak Island about 940 miles south-west of Anchorage.
Scientists in July noted increased activity in the crater at the summit of the volcano. Satellite images showed lava building and forming a dome-shaped accumulation.
Chris Waythomas, of the USGS, said in September that lava domes form a lid on a volcano's "plumbing", including the chamber holding the magma. When they grow big enough, lava domes can become unstable and will sometimes collapse. When the magma chamber decompresses it can lead to an explosion as the conduit inside the volcano suddenly becomes unsealed and gases escape.
Radar images earlier this month showed the dome had cracked and subsided, Mr Power said.
The Federal Aviation Administration and the airline industry get concerned for trans-Pacific flights when an ash cloud has the potential to exceed the 20,000ft (6,096m) threshold, as Cleveland Volcano has done in the past.
Cleveland Volcano's last major eruption was in 2001. It has had bursts of activity nearly every year since then, and the ash cloud today was not out of character.
"It's not unexpected for a volcano like Cleveland to do things like this," Mr Power said. "Unfortunately, Cleveland is one of those that is so remote, we have no on-ground monitoring or instrumentation there, so it's hard for us to pinpoint things any more accurately than we can do with satellite imagery."
The observatory had no satellite images of the crater after today's eruption.
New UK station Russia Today gives a very bizarre view of Britain
By performing as African Americans or Indians, white people get to play act a kind of 'imaginary liberation', writes Michael Mark Cohen
New essay by JK Rowling went live on Pottermore site this morning
Top Gear presenter is no stranger to foot-in-mouth controversy
- 1 Canadian actor punched in face after 'Islamophobia' experiment goes wrong in wake of Ottawa shooting
- 2 Topshop at centre of row over body image as 'shocking' skinny mannequin photo goes viral
- 3 Top Gear presenter Jeremy Clarkson criticised for beer tweet
- 4 The bubble bursts for Sodastream
- 5 If you think Russell Brand’s new book is confused, you should read what his critics have to say about it
'Nasa Confirms Six Days of Darkness in December': No, they don't - it's a hoax
Top Gear presenter Jeremy Clarkson criticised for beer tweet
The bubble bursts for Sodastream
Russian politician says Apple CEO Tim Cook should be 'banned' from country after coming out as gay
'Santa Claus' dead: John Moore starred in Coca Cola and Morrisons adverts
Pope Francis declares evolution and Big Bang theory are real and God is not 'a magician with a magic wand'
Huge surge in Ukip support after EU funding row, according to new poll
Ukip ‘exploiting grooming scandal’ to secure party’s first police chief
Nigel Farage: 'There’s nothing wrong with white people blacking up'
Maureen Lipman says 'she can't vote Labour while Ed Miliband is leader'
Muslims, immigration and teenage pregnancy: British people are ignorant about almost everything
£40000 - £65000 per annum + bonus + benefits + OT: Ampersand Consulting LLP: M...
£22800 - £33600 per annum: Randstad Education Manchester Secondary: The JobAt ...
£22800 - £33600 per annum: Randstad Education Manchester Secondary: Calling al...
£100 - £125 per day: Randstad Education Chelmsford: EYFS Teachers - East Essex...