Iceland has lowered its aviation alert level to orange from red, saying there was no sign of an imminent eruption at the Bardarbunga volcano.
And scientists at the Icelandic Meteorological Office said their announcement on Saturday that the volcano had experienced a subglacial eruption was wrong.
But the office cautioned that seismic activity at the volcano, which has been hit by thousands of earthquakes over the past week, was not slowing and an eruption remained a possibility in coming days.
Two earthquakes measuring over 5 in magnitude – the biggest yet – shook the volcano beneath the vast Vatnajokull glacier early yesterday.
On Saturday Iceland raised the alert for aviation to red, the highest level, warning that an ash-emitting eruption could be imminent. An orange alert indicates “heightened or escalating unrest with increased potential of eruption”.
After the alert was lowered, aviation authorities lifted a no-fly zone that had been imposed for 100 nautical miles by 140 nautical miles around the volcano.
A 2010 eruption of Iceland’s Eyjafjallajokul volcano caused a week of international aviation chaos, with more than 100,000 flights cancelled. Aviation officials closed Europe’s air space for five days out of fear that volcanic ash could harm jet engines.
Any new eruption would be likely to be less disruptive. European aviation authorities have changed their policy, giving airlines detailed information about the location and density of ash clouds but leaving decisions to airlines and national regulators.
The UK’s air traffic control organisation NATS said it was monitoring what it called a “dynamic situation”.