Iceland volcanoes chat
2004 Subglacial Eruption
A 5-day long eruption began at Grimsvotn Volcano on 1st November 2004. An intense swarm of volcanic earthquakes began 3 hours before the eruption. The eruption began under 150-200 m of ice and melted its way to the surface in 1 hour. On 2-3 November an eruption plume reached an altitude of 13 km, accompanied by volcanic lightning. The ash plume reached Norway, Finland, and Sweden.The total volume of the jökulhlaup was 0.5 cubic km.
A 10-day eruption began on 18th December 1998 within the caldera of Grímsvötn volcano, at a location 10 km S of the 1996 eruption. Within 10 minutes a plume rose 10 km above the Vatnajökull glacier. The plume was visible from Reykjavik, 200 km W. Eruption vents were located along a 1.3 km long fissure orientated E-W on the S caldera fault.
A 2-week long subglacial eruption began on 30th September 1996, along part of the East Rift Zone that traverses beneath the NW side of Vatnajökull, Europe's largest continental glacier. The eruption was preceded by earthquakes on 29th September at Bardarbunga volcano. The high-frequency tremor resulted from lateral magma
injection from a shallow magma chamber beneath Bardarbunga toward the 1996 eruption site at Gjalp.
Within a day, the earthquake hypocenters migrated 20 km south, where a subglacial eruption started during the evening of 30th September. The eruption caused glacial ice to subside by 50 m in 4 hours, forming a bowl-like depression. On 2nd October the eruption broke through the ice, creating an ash plume 500 m high. By 3rd October the glacier had subsided over an area 8-9 km long and 2-3 km wide. On 4th October, water in the caldera lake reached this highest levels of the 20th century. The eruption occurred within 70 km of the great Laki fissure eruption of 1783-85.
An eruption began at Grimsvotn Volcano on 28 or 29 May 1983. The eruption broke through ice on 29th May and deposited a 5-km long thin layer of ash on the ice cap, south of the vent. Explosions occurred in the lake, and a steam plume rose to a height of 8000 m.
On 28th January 1982 a glacier burst (jökulhlaup) occurred at Grímsvötn caldera in Vatnajökull glacier. The eruption volume was 1.3 cubic km and lowered the ice level in the caldera by 50 m.
A glacial outburst flood occurred at Grimsvotn Volcano in March 1972.
Laki (Skaftar Fires) and Grimsvotn eruptions 1783-1785
The eruption at Laki began on 8th June 1783 with a brief explosive event on a short fissure, and lava rapidly began to flow into the Skaftfi river gorge. Lava reached the lowlands, 35 km away, four days later.
Laki eruption created a 25 km long fracture and basalt lava flows extended 70 km. The lava flow covered 565 square km (14.7 cubic km). Large amounts of gas were produced in the eruption which covered most of Europe in a blue haze.
Fluorine was released by the eruption and cattle died from eating the contaminated grass. Over 200 000 livestock were killed in Iceland and the resulting famine resulted in 10 000 deaths.
More quakes at Vatnajokull....and a mag 3+ quake as well!
Here's the latest view of Eyjaf... No notable increase in water flow or jokull underway, and harmonic tremble seems fairly stable (though unlike the original eruption, that needed to melt away previous eruptive material, any magma left in chambers and sills would still be pretty warm and viscous, perhaps lending to a more rapid rise in magma flow.
Note in the image, is that steam at the crater or a cloud? You decide for yourslef, but for me it's a trick of the light and is a backlit by the setting sun.
In summary, there could be awful lot of coincidence going on here and nothing will come from this. On the other hand we might be seeing the first signs of a new eruption. I'm sure other more knowledgable than me here will choose their own interpretation :)
An earthquake of 4.9 mag has just been reported in the vicinity of Vatnajokull. There is no confirmation of this quake at the moment via USGS, and so the quality and location of this event are currently sketchy...
I see there are reports starting to come out about the larger one having tremors now:
“It is really strange how this news came into existence. I wasn’t even warning of a likely eruption at Bardarbunga [in the interview],” he told IceNews. “The things I emphasised in my interview with RUV’s Bjorn Malmqvist were that the earthquakes at Bardarbunga and Kistufell last week are not unusual, there are often movements there, and sometimes much bigger than this.
With a significant increase in earthquake activity today is the Krísuvík volcano setting up for an eruption?
Edit: These data show the ongoing swarm rather well:
Perhaps it'll settle down again but it might be worth keeping an eye on, just in case.