New 2011 volcano "Grimsvotn". The volcano, which lies under the Vatnajokull glacier in south-east Iceland, last erupted in 2004.
In 2010, plumes of ash from Iceland's Eyjafjallajokull volcano caused weeks of air travel chaos across Europe.
Officials say the latest eruption is unlikely to cause similar problems, although a flight ban has been imposed around the area.
Volcanic eruptions are common in Iceland, which lies along the Mid-Atlantic Ridge that divides the Eurasian and North American continental plates.
Icelandic Meteorological Office geologist Hjorleifur Sveinbjornsson told Reuters that Grimsvotn had thrown a plume of white smoke about 15km (nine miles) into the air.
"It can be a big eruption, but it is unlikely to be like last year," he added.
Iceland's Isavia airport authority said a flight ban of 120 nautical miles had been imposed around the area.
New Volcanic Ash from the Grimsvotn Glacier Eruption – own a piece of modern history!
The grey ash originates from a depth of 7km and is more than 1100 degrees in Celsius (or 2000 in Fahrenheit) when it emerges to the surface and comes into contact with the glacial ice, which lays 300 metres thick above.
When the hot lava comes into contact with the ice, it causes enormous steam explosions, resulting in millions of tons of new solid lava being thrown into the atmosphere as tiny light weight particles, i.e. volcanic ash.
This air travel disruption is the most extensive one in history and now you can own a piece of history – a sample of this very volcanic ash.
Nammi.is now offers ash samples from the eruption, which are sent out in a glass jar (160 grams) and shipped to customers in a thick cardboard paperbox.
All profits from the sale of the ash will be donated to ICESAR (www.icesar.com) association that have been helping with the safety in the area.
