The ash plume created by the eruption of Iceland’s Grímsvötn volcano will reach Canada by Thursday 26th May 2011. The ash cloud has now reached much of Western Europe and will soon reach parts of North America. The aviation colour code is red and the current height of the ash cloud is 5km.
Flights have been cancelled in the UK, though Ryanair is contesting the classification of the red zone. The flight operator has contested the measurement of ash particles by the UK Civil Aviation Authority:
“Earlier today Ryanair confirmed that it operated a one hour verification flight up to 41,000 feet in Scottish airspace this morning (24th May). The aircraft took off from Glasgow Prestwick, flew to Inverness, on to Aberdeen and down to Edinburgh – all of which according to the UK Met Office charts were in the “red zone” of “high ash concentration”.
“During the flight there was no visible volcanic ash cloud or any other presence of volcanic ash and the post flight inspection revealed no evidence of volcanic ash on the airframe, wings or engines. The absence of any volcanic ash in the atmosphere supports Ryanair’s stated view that there is no safety threat to aircraft in this mythical “red zone” which is another misguided invention by the UK Met. Office and the Civil Aviation Authority (CAA).
“Ryanair has also received written confirmation from both its airframe and engine manufacturers that it is safe to operate in these so called “red zones” and, in any event, Ryanair’s verification flight this morning confirms that the “red zone” over Scotland is non-existent.
“Ryanair has renewed its calls on both the UK CAA and the IAA to reopen the airspace over Scotland and allow airlines to operate flights safely following the verification flight.”
Icelandic Meteorological Office and Institute of Earth Sciences, University of Iceland compiled an update on the eruption, which included an analysis of an ash sample from the village of Kirkjubæjarklaustur:
“The grains are glassy with micro crystals of plagioclase. Samples well sorted.
Whole rock analysis: Basalt, with 50-51 Wt% SiO2
Leachate results: 5-10 mg/kg of water dissolvable flour
Grain size distribution: about 10% of the volume of the analysed sample is finer than 10 micrometers”
Around 300 lightning strikes were reported within an hour on the 22nd May 2011. The eruption site itself is reported to be experiencing violent interaction between magma and water:
“The eruption site is in the South West corner of the Grímsvötn caldera, in the same site as the 2004 eruption. The basaltic magma is fragmented into tephra in violent magma-water interaction. Very powerful explosions occur at the eruption site.”
The eruption site has also experienced substantial subsidence, with a CGPS station 5km from the erupting volcano moving 50cm in two days and subsiding by 25cm.