Holuhraun eruption about to exceed 1947 eruption

"The lava field that has formed is one of the largest that has appeared in Iceland in a long time," claims Magnús Tumi Guðmundsson geophysicist in an overview statement about the Holuhraun eruption, published last night at the Institute of Earth Sciences homepage. The eruption is now into its fourth week of non-stop activity.

"Of all the eruptions in Iceland over the past 150 years, only the lava field from the 1947 eruption in Hekla created a larger lava field, 0.8 cubic kilometers, but that eruption lasted for 13 months. If the Holuhraun eruption continues at its current strength, it will reach the same volume in just two weeks," Magnús continues.

The average lava flow over the past 3 weeks has been measured at 230-350 cubic meters a second, according to the latest readings. For comparison the average water flow of Þjórsá is 350 cubic meters by the Urriðafoss waterfall and around 370 cubic meters when it reaches Selfoss.

A field survey team from the Institute of Earth Sciences went on Friday and Saturday and performed measurements on the thickness of the lava at 12 different points, from the crater right down to where the lava meets the Jökulsá river. The team was assisted by additional survey team members from Landsvirkjun. The edge of the lava measures 8 meters high on average on the north side, but the thickness is most along the center line of the lava field, according to the Institute of Earth Sciences homepage.

If we go along the center line from the crater in a east by southeast direction, towards the Jökulsá river, the thickness of the lava fields is most by the craters themselves, around 30 meters, but around 18-22 meters elsewhere. The average thickness is believed to be around 14 meters.

According to a map that Ingibjörg Jónsdóttir at the Institute of Earth Sciences has compiled with the latest data, the size of the lava field was 37 square kilometers on Saturday. The volume of the lava field is calculated by multiplying the size of the field with its thickness, which gives a result of about 0.5 cubic kilometers, with a margin of error of about 0.1 cubic kilometers.