Costa Rica’s National Seismological Network has upgraded the color threat level to yellow of Turrialba Volcano, in the province of Cartago east of the capital.
A statement issued by Raúl Mora-Amador, coordinator of Seismology, Volcanology and Geophysical Exploration at the University of Costa Rica, indicates a threat level of yellow means that the National Seismological Network believes an eruption is “probable” in a matter of days, weeks or a few months.
The upgrade in the threat level is due to “important changes in seismic activity of Volcano Turrialba associated with the movement of fluids, gas and magma beneath the surface, different from that observed in past years,” Mora-Amador’s statement says.
Temperatures around some fumaroles on the volcano have risen to as much as 800° Celsius, accompanied by eruptions of ash. High-temperature emissions of volcanic gases including sulfur dioxide have increased, causing incandescence in some of the fumaroles, Mora-Amador said, adding that the internal wall of the active crater is very weak due to hydrothermal changes in the volcano. Mora-Amador indicated this could mean a major eruption could jettison material into the atmosphere.
Turrialba is the only volcano in the country currently with a yellow threat-level indicator. An upgrade to red would mean an eruptions is imminent.
