Scientists from the Volcanological and Seismological Observatory of Costa Rica (OVSICORI), based at the National University (UNA), noticed some changes to the landscape at Turrialba volcano during three recent visits.

Researchers who toured the area during the last two weeks of August reported that “yellow, straw-colored circles” covered approximately four square kilometers of trees. They said other plants appeared to have sustained wind damage.

Investigators also discovered new crevices that are emitting plumes of steam and sulfur. The cracks had expanded up to 12 centimeters in width and gases rose up to 300 meters.

“These observations are more intense than ones we have noticed before, but it's nothing extremely dangerous,” said Juan Segura, a volcanologist at OVSICORI.

Segura said the trees could have been yellowed by the vapor the new crevices are emitting or by this year's dry weather conditions.

He noted that those who want to visit the area should do so on the south and southwest sides to avoid inhaling the toxic gases being released by the mountain.