IMO and The Icelandic Civile Protection Agency reassess the status for Öræfajökull
Localized hazards still possible. The volcano poses no imminent hazard to aviation.
It is close to nine months since an unrest in Öræfajökull was detected. The unrest was apparent from elevated seismicity, the development of a depression in the ice-surface (cauldron) within the caldera, and the presence of geothermal gases from a glacial river. At this time, the geothermal activity beneath Öræfajökull was assessed to be high relative to previous decades.
As that behaviour was above known background conditions, it could potentially indicate increased risk of eruptive activity that could affect air traffic. Consequently, the Icelandic Meteorological Office raised the Aviation Color Code for Öræfajökull from Green to Yellow. At the same time, the Icelandic Civil Protection and Emergency Management raised their alert level to Uncertainty phase.
Since the unrest in September 2017, the level of monitoring around the volcano has increased significantly by the addition of new monitoring equipment. This increased capability means that any future unrest can be followed more closely, hopefully leading to an early warning of a potential eruption.
The level of earthquake activity at Öræfajökull has been stable for the last months, with signs that the earthquakes are becoming smaller with time. Hydrological and geochemical measurements show stable values. Measurements in late March indicate that the geothermal heat output beneath the cauldron has diminished significantly from what is was when the cauldron formed. There is a possible small, ongoing inflation signal in Öræfajökull, however there are no signs of an imminent eruption.
The uncertainty phase declared by the Icelandic Civil Protection and Emergency Management remains in force
Considering the information above, it is assessed that Öræfajökull volcano is currently not posing an imminent hazard to aviation. Hence, the Aviation Color Code is downgraded from Yellow to Green.
However, given the recent unrest at Öræfajökull, visitors to the area should be aware that localized hazards are still possible. These hazards include unexpected glacial flooding, gas pollution and landslides that could occur without warning. Note that the uncertainty phase declared by the Icelandic Civil Protection and Emergency Management remains in force.
The Icelandic Meteorological Office monitors Öræfajökull, and all other active volcanoes in the country, 24 hours a day. Any changes will be communicated immediately via standard channels.
