Thousands of small intense earthquakes are rocking Iceland amid concerns that one of the country's volcanoes may be close to erupting.
Air France, Deutsche Lufthansa, EasyJet and Delta Air Lines are among carriers watching the Bardarbunga volcano. Iceland has raised its aviation alert level for the risk of a possible volcanic eruption to orange - the second-most severe level.
The alert is worrisome because of the chaos that followed the April 2010 eruption of Eyjafjallajokul, when more than 100,000 flights were cancelled.
Eyjafjallajokul caused about US$1.7 billion (NZ$2.02bn) in lost revenue. Ash represents a menace to jetliners because the glass-like particles can stop turbines by melting and congealing.
Airline traffic in Northern Europe would be disrupted "if the winds, as we're seeing them today, continue" in a Bardarbunga eruption, said Melissa Anne Pfeffer, atmospheric volcanologist at the Icelandic Met Office.
Eurocontrol, the region's air traffic manager, said there is currently no impact on aviation from Bardarbunga. The volcano lies beneath Vatnajokull, Europe's largest glacier, and last erupted in 1996.
Some 3000 earthquakes have taken place since Saturday in Bardarbunga - a subglacial stratovolcano located under Iceland's largest glacier. Iceland's Meteorological Office said that no earthquakes above magnitude 3 have been recorded in the last 24 hours.
Seismologists said on Tuesday (local time) magma is moving, but it is travelling horizontally.
A VOLCANO BY ANY OTHER NAME...
With Bardarbunga on the point of eruption, it’s proving to be another Icelandic tongue twister.
It is actually one of the easier Icelandic lava spitters to pronounce and is meant to be said ba-thar-bunga.
People will remember news presenters and reporters trying to rattle off Eyjafjallajokul (pronounced EH-ya-fi-AHT-la-yo-coot), which aused the cancellation of more than 100,000 flights when it started spitting ash in 2010.
Let's just hope that Skjaldbreiur (Sky-ald-bray-the) and Snaefellsjokull (Snay-fetls-yuh-kut) do not go off any time soon.
You can also have a crack at trying to pronounce Theistareykjarbunga. No clear pronunciation could be found for this so you might need to ask an Icelandic friend for help.
Other honourable mentions from around the world include Russia's Kliuchevskoi (klee-u-che-vis-koi), Chile's Aucanquilcha (OW-kahn-KEEL-chuh), Mexico's Popocatepetl (Po-po-ca-te-petal).
- AP, Bloomberg News, Stuff