Scientists have several ways of forecasting when the Eyjafjallajökull eruption will stop. But their data – and history – suggest the Iceland volcano's ash cloud could persist for some time.
The most pressing question for European travelers is the one that is nearly impossible to answer.
For scientists watching every burp and hiccup from Iceland's volcano, the best they can do is essentially hold an ear to the subterranean railroad track beneath Eyjafjallajökull (pronounced: AY-ya-FYAT-la-yur-kutt).
The rumblings of small earthquakes can suggest that magma is still welling up from the bowels of the earth, feeding the eruption. The distension of the mountain itself – measured through global positioning system devices – can also provide hints as to whether the volcano is swelling or deflating.
As of last week, scientists were still measuring dozens of small earthquakes beneath the volcano, suggesting that no end was in sight.
All of which leaves European air travelers worrying about Icelandic tephra as much as whether they can stow their carry-on in the overhead compartment.
If history offers any guide, Eyjafjallajökull won’t cease to become Europe’s longest four-letter word until May 2011. The last time Eyjafjallajökull erupted, in December 1821, it did not stop until January 1823 – about 14 months.