QCOSTARICA – The analysis carried out by experts from the Volcanological and Seismological Observatory of Costa Rica (Ovsicori) on the materials released by the Rincón de la Vieja volcano, in Guanacaste, on Monday, June 28, reveals that such strong eruptions are not expected soon.
This was detailed by Javier Pacheco, an Ovsicori researcher, who said that the amount of juvenile magma found in the samples was very little, which reveals that the interaction with a recent magmatic body was minimal.
“There was no direct interaction of the magma with the hydrothermal system. It was not a phreatomagmatic eruption, but it was due to the indirect relationship between gases and the volcano’s aquifer,” he explained.
The ash expelled reached some five or six kilometers away, as there were reports from Buenos Aires de Aguas Claras and Gavilán de Dos Ríos, canton of Upala. It is the strongest eruption in Rincón de la Vieja in the last 25 years.
The chemical and petrology analysis of the materials, as well as the deformation of the volcano itself, show that what happened was the rupture of a seal that had been formed in the magmatic chamber and that prevented the exit of gases.
Last year there were more than 1,400 eruptions that kept that seal in the crater semi-open, but when it ceased, in December 2020, fluids began to accumulate in the hydrothermal system and internal pressure increased.
The June 28 eruption cleared the ducts by removing the plug. Now the colossus, which is 1,916 meters (6,286) above sea level, has returned to small eruptions like the three that occurred last weekend.
From now on, gases are expected to escape more easily into the atmosphere, although small accumulations remain, said the Ovsicori scientist.
As magmatic gas reaches temperatures of up to 800 degrees Celsius (1,472 F), when it comes into contact with water, it suddenly turns it into steam and that is what has been seen in recent days.
Most of the damage caused by acid rain to the vegetation occurred within the park itself and some of the neighboring farms in the north and northeast sector, where there is little agriculture. Rather, it was some cattle pastures that were affected.