The total amount of lava from the Holuhraun eruption is now larger than all the buildings in Iceland - combined.
The size of the lava flow is now estimated to be between 25-30 square kilometers, which makes it one of the largest eruptions in Iceland since the 19th century, especially considering the short time the eruption has lasted. By comparison the lava flow from the Krafla volcanic episode from 1975-1984 was 60 square kilometers, and estimated to have been around 250 million cubic meters. But square kilometers only tell half the story.
Ármann Höskuldsson, volcanologist at the University of Iceland, says that it's reasonable to estimate that the eruption has passed 200 million cubic meters, with 250 million cubic meters as the maximum estimate. "It's already bigger than the entire Krafla episode. In many ways this eruption is comparable to the Krafla episode with the biggest difference being that this is closer to the hot spot."
It's when people look at the lava flow in cubic meters that people start to realize the magnitude of the eruption north of the Dyngjujökull glacier. Using only the lowest estimate, all that lava could fill up the Hallgrímskirkja church 8300 times. If the highest estimate is used, it could be filled 10.400 times.
According to data from the Icelandic National Registry, the total space used by all buildings in Iceland amounts to 148 million cubic meters. So not only has the eruption already surpassed that, but is rapidly approaching double that volume.
Author and geophysicist Ari Trausti Guðmundsson is well familiar with the history of volcanic eruptions in Iceland, as he has written several books on the subject. He explains that the volume of the new lava field is, on one hand, based on carefully calculated square meters, and then the estimated thickness of the lava. The cubic volume is when those two numbers are multiplied together.
"For comparison I can name that the Heimaey eruption in 1973 reaches 200 million cubic meters. It's very thick but it's only 3,4 square kilometers. The Hekla eruption in 1947 took 13 months and ended at 800-900 million cubic meters, and the Laki eruption in 1783 took only 8 months and is estimated to have ended in 14 billion cubic meters," says Ari Trausti.