Loud explosion noises at the eruption site
Loud bangs are heard regularly at the eruption site at Litli-Hrútur. The reason for the bangs is methane explosions.
The Icelandic Met Office reports this on its Facebook page.
It shows that when lava flows over a vegetated area, methane gas can form when vegetation is not completely burned. The gas then builds up in the gaps and voids in the lava flow.
“It mixes with oxygen and when it is bombarded with a burning ember or flame from the volcanic eruption, an explosion occurs.”
The Icelandic Met Office says there are reasons to avoid this hazard and not to get too close to the edge of the lava.