Tourists visiting the Poás Volcano on Sunday afternoon were forced to evacuate the popular national park as a preventive measure due to an increase in the emanation of gases from the crater.
Park administrators ordered the evacuation at 1 p.m. One hour later, the park closed for the day, ahead of its usual 3:30 p.m. quitting time.
The Volcanological and Seismological Observatory (OVSICORI) reported that gases come from a new fumarole that formed in the volcano last week. Abundant water coming from the fumarole formed a small creek, rich in sediments.
“Vapor from the fumarole is also rich in acid gases and registers a temperature of 90 degrees Celsius (194 °F),” OVSICORI reported Monday.
Gases on Sunday reached the parks’ viewpoints area and caused minor respiratory problems for some tourists and park officials, the report added.
Watch the water and vapor coming from the crater:
OVSICORI noted that gas emitted between March 28 and April 4 increased from an average of 19 tons to 180 tons per day.
Most of these emanations — 75 percent — come from the crater’s lake. The other 25 percent come from the lava dome, which is approaching the surface, OVSICORI stated.
Vulcanologist María Martínez said in a written response that in January, scientists detected a volume of fresh magma from deeper levels that are pushing up toward the surface. Martínez said they also found a dense mist, rich in acids of magmatic origin, on the lake’s surface.
“The plume of gas and vapor is heading toward the city of Grecia in the province of Alajuela,” she said.
The agency reported that they recorded an increase in seismic activity and gas emissions starting on March 30. They also recorded a spike in the number of small eruptions in the crater’s lake. OVSICORI’s experts are currently collecting samples from the crater to evaluate the situation and assess the possibilities of lava flows.
The National System of Conservation Areas (SINAC) confirmed to The Tico Times that Poás Volcano National Park is open to the public, but that officials are ready to enforce all necessary measures with visitors according to emergency protocols.
SINAC spokesman Francesco Di Palma said in a written response that park administrators are working closely with experts to implement the appropriate measures for protecting visitors and park staffers.
Starting this week, park officials are restricting the number of tourists entering the park at the same time, and reducing the time they can stay inside. They also advise tourists to leave the viewpoints immediately if they experience any respiratory problems.
“We will evacuate all tourists and we’ll close the park for as long as is deemed necessary to protect visitors,” Di Palma said.
Poás, located in the province of Alajuela, 47 kilometers northwest of San José, is Costa Rica’s second most-visited national park.