Dr Robin George Andrews AT SquigglyVolcano
The eruption isn't happening within Grindavík, but according to two scientists, this may be a "worst case scenario" as the lava is erupting extremely close to both the town and the nearby geothermal powerplant.
https://www.ruv.is/english/2023-12-18-eruption-on-reykjanes-peninsula-399922
"This is not a tourist eruption"Víðir Reynisson of Civil Defence says that information is awaited from scientists about the exact size and flow of lava.
"We don't have the exact location of it. It appears to be flowing in all directions from the crack, which appears to be quite large. The jets [of lava] are quite high, so it appears to be a powerful eruption at the beginning."
It must be assumed that lava can both flow towards Grindavík and onto the defences [around Svartsengi]. Víðir is asking people to stay home, to give emergency responders time to handle this task. Don't go out on Reykjanesbraut, for example.
"This is not a tourist eruption we are looking at."
and
Geophysicist: "worst case scenario"Benedikt Ófeigsson, a geophysicist at the Icelandic Met Office, says that the eruption is as close to the magma intrusion as can be imagined.
He says everyone had the expected minimum notice of the eruption, which is nonetheless a very short period. He had expected more notice.
He calls this a "worst case scenario".
and
Þorvaldur Þórðarson, a volcanologist, says that at first glance the eruption is in the worst location for both Grindavík and Svartsengi [area of the power station and Blue Lagoon].
Þorvalður reiterates that this is at first glance, but he guesses that the highest eruptive jets are about a hundred meters high, and the eruption is quite powerful.