Iceland’s meteorological office (IMO) lowered the risk level for an eruption at the Bardarbunga volcano to orange from red on August 24, but warned that there are “no indications that seismic activity is slowing down.” A day earlier, scientists had raised the threat warning to red.

Volcanic ash clouds significantly disrupted air traffic in western Europe in 2010, but Eurocontrol has said it is now better prepared to deal with another event.

Icelandic authorities said the intense seismic activity that began August 16 has already caused more than 2,600 earthquakes of varying intensity. Scientists detected very strong indications of ongoing magma movement at Bardarbunga volcano, which is buried beneath a glacier, corroborated by GPS measurements in the north and east of the volcano, although no lava has broken through to the surface so far.

“At present there are no signs of eruption, but it cannot be excluded that the current activity will result in an explosive sub-glacial eruption, leading to an outburst and ash emission,” the IMO said on August 24. The agency will release online updates of any significant intensity changes, either up or down, as they become known.