The molten rock that has built up under southwest Iceland has erupted in spectacular fountains of lava.
A gash two miles long has opened up on the Reykjanes Peninsula, spewing between 100 and 200 cubic meters of lava every second. This is far more than in other recent outbreaks in the area.
There had been a longer pause in the volcanic rumbles.
It’s been five weeks 4,000 people were evacuated from the nearby fishing town of Grindavik in the middle of the night after an intense swarm of earthquakes.
But seismic activity died down in the following days, and scientists began to wonder if the magma would solidify and never reach the surface.
But on Monday night there was another swarm of earthquakes, and the surface cracked soon after.
The lava is currently flowing about half a mile per hour north and west, away from the town, which is a little more than a mile from the south end of the eruption.
But the rift in the Earth has widened, and if it reaches a south-facing slope, the city could be in danger.
The Svartsengi power plant, which supplies electricity to thousands of homes, also appears to be safe for now. The authorities have built a wall of stone and earth to protect the facility from any lava flow.
According to the Icelandic Met Office, the seismic and GPS data suggest that the eruption has subsided as the night has progressed. But that doesn’t mean it will be a short burst of volcanic activity.
It is likely that the enormous pressure that pushed the magma towards the surface has been reduced.
Scientists want to take a closer look at the eruption area in daylight to get a better idea of what’s going on.
Authorities had plenty of warnings that this could happen, and people have been moved out of harm’s way.
Now it’s just about letting nature take its course.