Subgacial Eruption in Vatnajökull
Iceland -- 1996

On September 29, 1996 at 10:48 an earthquake of magnitude 5 on the Richter scale was detected within the Vatnajökull icecap in SE Iceland. This event was followed by an intense earthquake swarm with a large number of small events with intermittent larger quakes of magnitude 3-4 on the Richter scale. The activity continued at similar level until shortly before midnight on September 30th when volcanic tremor was recorded and earthquake shocks became less frequent. In the afternoon of September 29 a warning was issued to national and international aviation authorities that an explosive (phreatic) eruption might be expected within the near future and an ash cloud might interfere with the dense air traffic across the Atlantic.

In the morning of October 1st an over flight discovered a subsidence bowl in the glacier surface at a location where an eruption had occurred in 1938. More or less continuous over flights during the day observed continuous increase in the size and depth of the initial subsidence bowl as three additional bowls formed on a line N30E indicating intensive melting at the base of the glacier along a fissure 5-6 km long.

Simultaneously the ice cover on the 10 km diameter Grímsvotn caldera some 15 km to the south of the active subglacial fissure started to rise indicating that melt water from the eruption was flowing into the caldera depression and lifting its ice cover.
This text describes the beginning of a violent process of eruptions, leading eventually to a partial meltdown of the glacier.
The above citation is the top part of an introductory file originally to be found at the website of the Volcanological Institute of Iceland. The page has gone from that website, it seems, but it still is available here at the website of the University of Michigan mirror.
A personal account of the eruption is provided by the Glacier Eruption Filming Diary by filmmaker Villi Knudsen -- sadly this page and Knudsen's Volcano Show seem to have vanished from the Web.

 

Images

I have collected a number of images about the eruption from the Internet and I kept them because I like them, and therefore I can also make them available to others, hence this page. To reduce loading time, I've put the images on four pages (each page is of the other of 40 kb); the pictures on this page are just an example. The file size in bytes follows the name of the file. (The images are given in a rather arbitrary order.) I'm afraid that only some of the pictures have a caption; if you want to know more visit the above mentioned sites.

Page 1, example: crater.jpg 17703

Page 2, example: gos12.jpg 72278

Page 3, example: gos9.jpg 56332

Page 4, example: sig2m.jpg 38718

The source of the images is mainly Bardarbunga: Volcanic Eruption under Vatnajökull [page has gone].
Some of image came from the site of the Volcanological Institute of Iceland, the site of an air company [page has gone] and the site of Magnus M. Halldorsson.
These pages provide links to more sites with images and info.

For any questions regarding ownership and rights of these pictures, you have to consult the Web sites listed.

<=== main page of pictures found on Internet

 
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created: 7 November 1996
last modified: 14 June 2011