The Island Mountains’ Glacier or rather its mountain range is among the highest of the country, 5500 feet (1666m).  It derives its name from the Island Archipelago off the south coast, The Vestman Islands.  This mountain massif is actually the result of continuous eruptions during thousands of years and a vast crater on top has probably been active a few times during historic times of this country.  The only documented eruptions took place in 920, 1612, which was seen all the way to the northern part of the country, and during the period 1821-23.  The latter two eruptions caused at least damage to property by glacier bursts (floods) and ash fall.  The latter caused a three hours’ flood, covering the wide valley floor north of the mountain.  Before and around the turn of the last century, an increased earthquake activity and escaping gasses were watched closely.  This volcano, and many others, is within the most active 50 miles wide zone of the country.

On March 20th 2010 (spring equinox), shortly before midnight, a half a kilometre long fissure opened up and an eruption started just to the west of the hiking trail in mountain pass Fimmvorduhals.  Earthquakes and tremours had been monitored since the summer of 2009, and the authorities were well prepared for the measures to be taken in case of an eruption.  People were temporarily evacuated from the area and roads were closed.  They were opened again in the afternoon.  Scientists say, that this erution probably will count among the small ones.  Lava started flowing across the hiking trail, down into the Hrunagil gorge on the 22nd, melting snow and causing temporary swelling of river Krossa.  The trail is thus closed and it depends on the duration of the eruption, when it will be passable again.
On March 31st, a NW-SE eruptive fissure opened up a bit further northwest of the original crater, which remained active.  Molten lava flowed from the new fissure down into the Hvannargil gorge further north and added to the lava volume.  The police and the rescue corps present decided to evacuate the eruption area.  In the evening, it was decided to evacuate the Godaland and Thorsmork areas as well and close access to them for the time being.  The whole mountain was unstable, and noone knew what would and could happen next.    Those who visit the area have to be aware of the risk involved and be prepared for the worst.
April 13th - 14th 2010.  No emission of lava from the fissure of March 31st.  Eruption pause or end.
April 14th 2010.  Shortly after midnight the mountain massif Eyjafjoll's caldera started erupting.  Flood waves rushed in two directions, mainly to the north into river Markarfljot's wide valley, threatening farm communities and communications on rd #1, which was removed partly to save a relatively new bridge.  Approximately 700 people were evacuated from their homes.  The flood wave to the south threatens an inabited area around farm Thorvaldseyri, and will cause damage to rd #1, fields and meadows.  The westerly winds carried ash and tephra eastwards, where large areas were covered.  It is expected that the tephra distribution might disturb air communications to Northern Europe (Scandinavia).
May 3rd 2010.  The last few days, one crater has been active in one of the ice cauldrons.  Lava has been flowing to the north under the glacier tongue Gigjokull and increasing meltwater on the outwash plain.  Today the temperature of the main glacial river, Markarfljot, was measured 11-17°C at the old bridge (1934).
A German research plane flew to the southeast along the ash plume, which is carried at relarively low altitudes (>20 thousand feet), and reported hight density of the ash all the way down to the latitude 60°N, which might cause some disruptions of flights.  Airports in Ireland and Scotland were closed as a result (May 4th and 5th).
According to scientists, the eruption is now more intense than in the beginning, but the ash (tephra) distribution is less likely to cause trouble because of coarser particles.
May 23rd 2010.  The eruption has been dwindling during the week.  A reporter flew over the crater in the afternoon and saw no sign of activity.  The volcano has paused or the eruption is over.

The icecap on top is the sixth largest of the country, and is relatively easily accessible from the mountain saddle Fimmvorduhals, the farms Seljavellir and Mork, and from the north at Stakkolt and Langanes.  Nowadays it is not considered a great deed or too much of an adventure to conquer the glaciers in specially equipped and modified jeeps or other vehicles.  A small Lada has even conquered this one.

Two glacier tongues fall steeply down to the foot of the northern slopes, The Gigjokull and The Steinsholtsjokull.  Both created lagoons, where it usually is possible to see some floating ice.  In 1967 a part of a precipice called Innstihaus, about 15 million cubic metres, broke of and collapsed on top of the glacier and into the lagoon from about 900 feet above.  This catastrophe caused a tremendous flood wave, carrying with it gigantic rocks and boulders all the way down to the main river, Markarfljot, which peaked at 21.000 cubic metres per second.  Right at the beginning of the 2010 eruption (March 20th), the Gigjokull lagoon was filled with alluvium, when meltwater came rushing down to the outwash plains.

Two aircraft have crashed on the icecap.  In 1952 an American rescue plane, with five on board, went down and only one body was found on location.  The other four obviously had survived and walked away, not to be found during the next few years.  Twelve years later, another body was found and a wedding ring of another.  The glacier tongue delivered the remaining three bodies in the summer of 1966.  Scrap and pieces from the plane have been appearing gradually in and by the sides of the glacier.  In 1975, an American couple crashed and lost their lives.