Spectacular. Incredible. Those were the words of a couple of geologists on their honeymoon early on Thursday morning in Grindavik, watching a curtain of lava bubble in front of them after a volcano erupted near the southwestern Icelandic town.

A large sulfur dioxide gas cloud is blowing toward Keflavík International Airport. Authorities have told people nearby to stay indoors and keep their windows shut as pollution levels rise. Despite this, flights are running normally and the airport remains open.