For the fourth time in three months, Iceland’s volcano erupted, producing the strongest explosion to date. The explosion started on Saturday just before 8:30 p.m. local time and is still running strong, though scientists think it might be slowly decreasing.

According to national radio RUV, hundreds of guests were evacuated from Iceland’s most popular tourist destination, the Blue Lagoon thermal spa, as a result of the eruption. The eruption site is a few kilometers northeast of the 3,800-person seaside town of Grindavik, which is located roughly 50 kilometers southwest of Iceland’s capital, Reykjavik. Grindavik’s residents were told to leave their houses.

Only 20 kilometers north of the eruption site, Keflavik International Airport is Iceland’s primary international airport and is still open for business, with planes coming and going. Roads surrounding Grindavik remain closed, though.

The eruption, according to Iceland’s Meteorological Office, has opened a crack in the soil between the mountains of Stóra-Skógfell and Hagafell that is around 3 kilometers long. At a pace of roughly one kilometer per hour, lava is moving south and southeast and may eventually reach the ocean. Along the southern coast of the peninsula, defensive walls have been built to keep it from flooding the main road. So far, these walls have proven to be successful.

The village of Grindavik was evacuated in November of last year due to a sequence of earthquakes that caused significant fissures in the ground between the town and the neighboring mountain, Súlingarfell. The Svartsengi volcanic system, located north of Grindavik, had lain inactive for around 780 years prior to these most recent eruptions. Situated to the west of Fagradalsfjall, which erupted in March 2021 after been dormant for 6,000 years, is the location of the most recent eruption.

In November, after many minor earthquakes rocked Iceland’s most populous region, the Reykjanes Peninsula, authorities declared a state of emergency. The head of Iceland’s Civil Protection and Emergency Management, Vidir Reynisson, stressed that it is best to witness the eruption from a safe distance and that it is not a tourist attraction.

Keflavik Airport is still open despite worries about travel disruptions. The European Aviation Safety Agency (EASA) is ready to evaluate any volcanic ash cloud’s potential effects on aviation and provide suggestions in response.

Travelers should avoid Grindavik and observe local laws, according to European foreign offices, which also keep an eye on recommendations from Safe Travel Iceland and the Icelandic Met Office. Traveling to other areas of Iceland remains unaffected, despite the eruption region being closed until further notice.

The Blue Lagoon geothermal spa, which was evacuated after the eruption, is still closed and has had its activities halted indefinitely. Customers are reassured by management that the spa’s infrastructure is protected by barriers, and that changes or cancellations of reservations can be made as needed.