Watch: Costa Rica's Turrialba Volcano Erupts

Costa Rica's Turrialba volcano erupted early on Thursday morning, 30 miles east of the capital, San José, spewing a cloud of ash, gas and rocks. The country's National Seismological Network (RSN) released a video of the explosion taken with an infrared camera and showing the force of the blast.

"It was a single explosion but a really strong one. This means that there was high pressure inside the volcano," Javier Pacheco, a volcanologist with the Volcanological and Seismological Observatory of Costa Rica (OVSICORI), told local newspaper The Tico Times.

"Current wind patterns caused the expelled materials to travel southeast of the volcano," Mauricio Mora, a volcanologist at the RSN, added. Currently, seismic activity at the Turrialba "is relatively low but similar to that registered prior to the explosion," he said.

Tobías Bolaños Airport, in western San José, was briefly shut so staff could clean debris from the landing strip in the aftermath of the eruption, Costa Rica's Civil Aviation Administration reported. It was due to reopen at 11am local time.