The eruption began on the 20th of March 2010 after this eruptive phase however there was a brief pause before the volcano began to erupt again in April; this first minor eruption was the first cause of airport closure.
14 April - The start of the explosive phase occurred as the main eruption site is under the centre of the glacier. Sudden melt waters caused flooding nearby as it travelled down either side of the volcano forcing 800 people to evacuate.
15 April - The unusually stable jet stream caused the cloud to move over mainland Europe, closing airports in UK, Scandinavia and Northern Europe
16 April - An eruptive column reached 26,000 ft with lightning frequently seen within the plume.
17 April – Less explosively the eruption continued, with the plume rising 16,000 ft, not as high as before as it was not high enough to travel across Europe again; however the plume was still crossing over Northern Europe.
18 April - The Icelandic Meteorological Office (IMO) detected through radar that the plume is beneath 10,000 ft. No ash fall or floods we reported despite continuation of strong seismic activity.
19 April- IMO says that plume reached a height of 16,000 ft, up to 5-6km south of the eruption site. IMO state that the ash producing stage is giving way to lava flow.
20 April- The volcano was spewing heavy ash and lava after calming through the past 24 hours.
21 April- IMO reported a decrease in seismic activity also a decrease of ash ejection and increase in lava flow.
22 April- A nearby volcano, Katla, is known to have previously erupted after eruptions from Eyjafjallajokull, High seismic activity was recorded and scientists disregard any imminent threat of the volcano erupting.
24 April - 11 days since the second eruption phase, the plume reached 13,000 ft while mildly explosive.
28 April - Continued disruption to flights including some airports closing.
29 April- With less intensity at the peak, plume elevations, magma discharge and tremors continued similar to the previous week. This eruption phase has reached equilibrium as the rate of lava flow into the magma chamber is the same as the ejection of tephra (debris) out of the volcano; however it is not known how long this sate of equilibrium will last. The lava flow, which commenced on 21 April, has been melting the glacier ice and generating large amounts of steam where the lava met the ice.
2 May - The lava producing phase became larger than the explosive phase. The plume darkened, thickened and widened. The amount of tephra increased and the lava flow moved 3km north of the eruption site advancing further over the glacial edge. Glacier melt water and lava production increased as well as tremor levels intensifying. The plume extends to 13,000-17,700 ft in height and is visible 200km away.
3 May - The plume grew to between 16,000-18,000 ft. Due to wind conditions and new ash; airspaces were closed over the Outer Hebrides cancelling flights at Stornoway, Barra and Benbecula.
4 May - The plume reached 19,000-20,000 ft in height heading south-east visible 300-400km away. Tremor levels decreased whilst earthquakes were located beneath Eyjafjallajokull. Explosive activity and ash production was higher than the day before and airspace disruption continued in Ireland, United Kingdom and Scotland.
5 and 6 May - The volcano entered new phase and shift back from lava to ash production according IMO including a considerable increase in explosive activity and ash fall. The plume was recorded as 18,000-21,000 ft on 5 May, and 30,000 ft on 6 May. The cloud moved in a south-westerly direction allowing UK airspaces to open again.
7 and 8 May - Heavy ash fall resulted in the closing of school in southern Ireland. Air pollution is higher than measured before in Iceland and above the health limit. People were advised to stay inside their houses in the areas subjected to the ash fall.
9 May- The ash cloud caused disruption to transatlantic flights as it moved towards Spain. Flights were rerouted to Greenland and south Spain to avoid the cloud. Between the 8th and 9th of May air traffic faced disturbances in countries including Ireland, France, Spain and Portugal. After opening 19 airports on the 8th May, air traffic was forced to close 7 on the 9th.
10 May -Most of the effected airports reopened excluding some in Portuguese airspace and some in Iceland.
11 May - The radar measurements record the ash cloud reaching 16,000-20,000 ft
12 May - The average height of the cloud was between 13,000-16,000 ft and it peaked at 20,000 ft. Winds moved the cloud to head in a south easterly direction.
13 May - The ash plume rose to approx. 20,000 ft with some parts rising to 30,000 ft. Later that day 4 minor earthquakes occurred beneath Eyjafjallajokull. There is no indication of the eruptions stopping.
14 May - No major changes to explosive activity or size of plume.
15 May - Ash cloud rose 20,000-26,000 ft. Explosive activity is much the same as the days prior.
16 May - The ash cloud rose to 23,000-30,000 ft due to calm weather. An unusual amount of lightning strikes were recorded in the ash cloud in the past 24 hrs.
17 May- From 01:00 BST to 07:00, due to the ash cloud, CAA imposed a no-fly zone policy on the following airports: London Heathrow, Gatwick, Farnborough, London City, Shoreham, Biggin Hill, all airfields in Northern Ireland, Scottish Western Isles, Oban, Campbeltown, Caernarfon and Aberdeen. In Cardiff, operations are limited due to the closeness of the no-fly zone but the airport is still open. From 07:00 to 13:00, the following airports are still within the no-fly zone: Ronaldsway, Edinburgh, Aberdeen, Inverness and Northern Scotland; Cardiff, Swansea, Bristol and Farnborough. The airports Schiphol and Rotterdam in the Netherlands are closed until at least 2pm. The ash cloud reached a height of 20,000–23,000 ft occasionally reaching 30,000 ft. The wind around the volcano increased, reducing the height of the plume which is now drifting east. ATDN​et reports regular lightning activity up to 10 flashes per hour. The volcano is still explosive, but its output lessened somewhat since the 13 May. Large ash quantities have fallen on neighbouring communities and is expected to persist.
18 May - The plume stayed at an average of 23,000 ft. The wind was in a southerly direction at the top of the plume but a general east direction on the surface of the volcano. The ash cloud is moving in a north-easterly direction. ATDNet reported 70 lightning strikes between midnight and midday, up to 10 flashes per hour until 12:00 but decreased in the afternoon. The eruptive phase is ongoing and the ash cloud height suggest tephra ejection rate of 200 tonnes per second.
19 May - The ash cloud was lower than the previous day at 16,000-20,000 ft. Early in the morning the wind moved the cloud a north-westerly direction but later changing to north-easterly. ATDNet reported 20 lightning strikes between midnight and midday, considerably less the previous days. Due to heavy rainfall around the volcano and the fallen ash, heavy mudslides occurred in Svaðbæli River.
20 May - Due to weather the volcano has not been visible for two days, the radar shows no change in the ice cauldrons where the cinder cone is forming. The eruption is mostly explosive, no lava output. The ash cloud rose to 16,000 ft, the ash could was heading north but turned over the highlands in a north-east direction. Water discharge has decreased after an increase caused by rainfall the previous day. The height of the ash cloud decreased over the previous few days suggesting a decrease in magma flow. Fluctuations in ash fall and magma flow can be expected.
21 May - Water gauges were installed to monitor the potential for mudslides like the one occurring on 19 May. The plume is at a height of 9,800-11,500 ft first heading north-east but moved north-west by wind currents. No lightning strikes were detected that day. Many people who lived on the hillsides noticed bluish gas clouds which caused headaches. The plume decreased again to 4,900-6,600 ft due to the slow rate of explosive activity and magma flow.
22 May - The ash cloud was estimated at 13,000 ft according to the reconnaissance flight. Due to clouds no observations of lava flow were taken.
23 May - From pilot observations the ash cloud is estimated at 9,800 ft, the plume was entirely white meaning it was completely water vapour. Evidence from limited observations of the magma chamber and the amount f steam being generated, the explosion appears to be dormant.