A woman takes a picture with her mobile phone of the Copahue volcano spewing ash on Dec. 22, in Caviahue, Neuquen province, Argentina.

Cattle stand on the bank of Nahuel Huapi Lake, blanketed with ash from Chile's Puyehue-Cordon Caulle volcano, at Villa La Angostura in southern Argentina on June 16.

A cow is covered by ash from Chile's Puyehue-Cordon Caulle volcano in Villa La Angostura in southern Argentina on June 16.

Surfers paddle past icebergs covered in ash from the Grimsvotn volcano eruption, in the glacier lagoon at the base of Vatnajokull, Iceland, May 26. Iceland's Grimsvotn volcano is producing mostly steam rather than ash and should calm down within a few days, national police said on Thursday encouraging hopes there will be no further disruption to flights in northern Europe.

A member of a rescue team checks on a farmer near to Kirkjubaearklaustur, approx. 260 km from Reykjavik, Iceland, Monday, May 23, 2011. A dense cloud of ash from an Icelandic volcano was being blown toward Scotland Monday, forcing two airlines to cancel their flights, U.S. President Barack Obama to cut short his visit to Ireland and carriers across Europe to fear a repeat of the huge disruptions that stranded millions of passengers a year ago.

Picture taken on 23 May 2011 at around 10:00 AM GMT shows a man cleaning his car from volcanic ashes in the village of Kirkjubaejarklaustur, in the south of Iceland. Airspace over Iceland was closed 23 May 2011 after the North Atlantic country?s most-active volcano continued to spew ash. The plume above the Grimsvotn volcano was Monday estimated to be between 8-10 kilometres, the Icelandic Meteorological Office said. The volcano began to erupt 21 May 2011, and the plume was initially more than 20 kilometres high.

Farmers Thormar Eller and Henny Hrund go to check their livestock as an ash cloud is seen in background, near Kirkjubaearklaustur, approx. 260 km from Reykjavik, Iceland, Monday, May 23, 2011. A dense cloud of ash from an Icelandic volcano was being blown toward Scotland Monday, forcing two airlines to cancel their flights, U.S. President Barack Obama to cut short his visit to Ireland and carriers across Europe to fear a repeat of the huge disruptions that stranded millions of passengers a year ago.