On September 30th 1996, a
subglacial eruption started between the Grimsvotn caldera and
Bardarbunga (2000m). It melted a 3,5 km (2 miles) long and 500 m
wide area of the 600 m thick ice shield, which was named Gjalp.
The meltwater, 300-400
m│/sec., filled the caldera during the entire eruption
period to the extent of about 3,2 km│ until the
glacier burst started in the beginning of November. The eruption was
declared finished on
flood kept increasing until it peaked on November
22;30. One bridge was swept away completely and
the country's longest bridge was cut at both ends. Prior to this
glacier burst, River Skeidara was flooded in April, so the water volume
of the caldera was minimal. The first damages to
soon after the beginning of the November flood were the
telephone and glass fiber connections across the aluvial
plains, which led to
re-routing via the northern part of the country. The first
illustrated news from the glacier burst appeared in the afternoon of
the first day (5/11). Warnings were issued to the captains of
the fishing fleet off the south coast not to venture to close to the
spillage area because of the strong currents of the flood wave
entering the sea and all the mud and gravel carried with it. Two
days later the caldera was empty again and the destruction was
evaluated. It took about three weeks to build a provisional
bridge and repair the longest bridge. The ring road was opened
scientists estimated, that the enormous blocks of ice, which had been
carried long distances from the edge of the glacier and spread all
over the flooded area, would take at least two years to melt.
They, however, were proved wrong, because the melting was extremely
fast, only a few months.
A small eruption, just south of the southernmost
crater of the previous eruption (Gjalp), took place on
and created a depression in the ice cap. The
next day another long depression was created, when the flood water
tunnel under the ice collapsed from the exit of the caldera and far to
the south. The increased geothermal activity in the wake of the
eruptions continued for years and increased the flow of water into the
caldera, which was not filled up again to cause the regular glacier
bursts like before. Water collection in the caldera did not
commence until the drainage pass had been filled with massive ice.
The enormous fissure created by the 1996 eruption was soon filled with
ice and snow and left behind a dangerously crevassed depression in the
ice landscape. The construction of the new concrete bridge was
finished in 1998
18th) another subglacial eruption
started in the southernmost part of the caldera. It was first
spotted from a plane at 09;32, only 11 minutes after the beginning.
The plume of the eruption reached the altitude of 10 kilometres (6
miles) and most of the ash fell on the ice cap 3-4 miles southeast of
the crater. The following day the eruption started dwindling and
the wind carried the ash to the north. Ten days later, the
eruption was declared finished.
In 2004 (November 1st, 21;50)
a subglacial eruption started under the ice shield of the southwestern
part of the caldera and lasted 4-5 days. The plume reached 13 km
altitude. The eruption soon melted the ice above and continued
in the open until it came to an end during the night of day five.
It co-incided with a normal glacier burst of River Skeidara and added
to its volume, which also affected the discharge of rivers Gigja and
Nupsvotn further west on the outwash plain. The peak of the
flooding reached 4,900 m│/sec.
In 2010 (October 31st
) a glacier burst of river Gigjukvisl started. Sicentists expected it
to follow similiar lines as in 2004, but were surprised by the quicker
increase in volume the next day (>600 m│/sec.).
They do not exclude the possibility of a subglacial eruption with the
decreasing pressure in the emtying caldera 50 kilometres north of the
southern edge, where the flood water appears.
On November 3rd, at ten o'clock a.m., the flood water volume at the bridge
was measured 2600 m│/sec, and a peak of 4.000 m│/sec
was expected in the afternoon. At 02:30 a.m. increased earthquake
activity was observed in the Grimsvotn caldera. It was probably caused
by subglacial water flow changes.
The glacier burst peaked at 3.500 m│/sec, somewhat
less than expected, and the water continued receding until the end was
declared on November 9th without any volcanic activity.
May 21st (19:15).
First film of the eruption.
An ash plume was reported at 19:15, seen from Mt Lomagnupur on the south
coast and village Hella in the southwestern lowlands. At the
meteorological centre in Reykjavik, where volcanoes are monitored
constantly, the scientists observed tremours and earthquakes at 17:30, which
pointed to a pending eruption and alerted the media. They immediately
prepared a flight to the area for further information. The eruption
started just before 19:00 o'clock.
The ash was carried by northwesterly winds to the Glacial Lagoon on the
southeast coast, where it started falling at 22:00. At 22:07 the plume
reached 15 kilometres elevation. At 22:45 the Glacial Lagoon area was
totally darkened, no visibility.
The eruption has been placed in the ice free southwestern part of the
Grimsvotn area and the ashes are also falling on the Skeidararsandur outwash
plain and is very light in colour. Road #1 through that area was
closed because of lack of visibility a few minutes ago.
At 23:16, the plume had reach the hight of 20 kilometres, and scientists
could not predict how the eruption would develope. They said, however,
that it was much more powerful than in 2004. This statement was issued
after the first reconnaissance flight to the volcano this evening, and also,
that a minor glacier burst was probably pending approximately 12 hours after
the beginning of the eruption, if there were sufficient water in the
Fine ashes have already fallen as far east as in fishing village Hofn and as
far west as village Kirkjubaejarklaustur.
May 22nd. International flights were postphoned from Keflavik
airport at 08:00 for the time being and all domistic flights as well. This
morning fine ashes fell in river Tjorsa area in the southwestern lowlands.
The ash cloud was about 3 kilometres high and planes could fly above it
further east. Scientists have declared this eruption of Grimsvotn its
greatest for over a century.
The ring road between Kirkjubaejarklaustur and Freysnes is closed because of
no or very poor visibility.
A renowned geophysicist claims today, after observing the eruption from the
air, that the eruption is gradually subsiding, but could last for a few
days. Many Icelanders fear, that the Metoffice (London VAAC)
in England is going to react equally hysterically as last year and ban
flights all over Europe on usubstantiated grounds or evidence.
The ash plume went down to ten kilometres in the afternoon and stayed
between ten and fifteen in the evening. Very few of the domestic
animals, sheep, horses and cattle, have suffered. A few sheep were
found dead in home fields, where they are grazing during the
The ashes are brown in colour, not gray as during last year's eruption of
Eyjafjallajokull, and most likely contain less fluor.
The ash cloud reached the capital area of Iceland in the evening.
May 24th. Today the eruption has been stable and gradually
subsiding. Eruption tremours, monitored by the Icelandic Metoffice,
remain constant and the plume has been 8 kilometres high the whole day.
The main ash fall sector lies between village Vik in the middle of the south
coast and farm Kvisker, south east of glacier Oraefajokull, the country's
highest mountain. Stormy weather has added to the discomfort of the
people in the south east and made it difficult to stay outdoors.
Schools were cancelled yesterday and today and road #1 between Vik and
Freysnes has been closed.
According to forecast, ash clouds are expected to reach the northern part of
Russia and Ireland and Scotland tomorrow morning.
May 24th. The ash plume reaches three to five kilometres
elevation today. The progress of the eruption is as predicted to the
extent, that it subsides gradually. The tephra emission of the
eruptive fissure is estimatated 100
compared to 2000-3000 m3/sec yesterday.
Ash has fallen in most parts of the country without affecting domestic
flights, which were only cancelled during the second day of the eruption.
International flights were cancelled to and from England, Denmark and
Norway. More people seem to disagree with the conclusions of
London VAAC, and use their own judgement. Ryan Air
cancelled flights to and between Ireland and Scotland after declaring
unchanged flight schedules today. The Norwegians decided to ignore the
VAAC warnings and continued their scheduled flights.
The Icelandic authorities opened the ring road at 19:00 o'clock. A
team of scientists prepared a research expedition to the eruption area.
It headed for the glacier snout Skalafellsjokull, where it continued in its
special vehicles on the ice to the Grimsvotn area. In the evening the
eruption continued dwindling, at 20:00, only 50
and it was highly likely, that the ash production would come to an end soon.
During the 3-4 days of the eruption, much greater volume of ash was emitted
than during the whole Eyjafjalla-eruption (April 14th-May 23rd) last year.
All main airports of the country were closed at 23:00 to 08:00 next morning,
when the decision was to be revised.
May 25th. Keflavik international airport was opened at 8
o'clock this morning. According to people present in the eruption area
this morning, there is no eruptive activity. The crater mostly emits
steam during frequent, but small ash explosions, at least for the time
being. Ash only falls in its immediate neighbourhood. The
eruption might be over or pausing. Some German airports were closed to noon.
Authorities do not expect any further flight interruptions because of this
May 26th. The intermittent and differently powerful explosions
of the eruptive fissure continued. A twenty minutes long series of
explosions sent the ash plume eight kilometres in the air and then lesser
activity prevailed. The eruption is therefore not quite over.
May 28th. A
coast guard plane reported a 1,5 kilometre high plume of steam.
Scientist say, that ash plumes can still be expected.
May 30th. The eruption is officially over.