“Even a small shift under one of these giants could cause an eruption,” says the Costa Rica Times.
At least four of the seven active volcanoes in Costa Rica are in the crosshairs of scientists after the earthquake of 7.6 magnitude on Wednesday. These are Arenal (Alajuela), Rincon de la Vieja (Guanacaste), Turrialba (Cartago) and Poás (Alajuela).
According to specialists at the Volcanological and Seismological Observatory of Costa Rica (OVSICORI-A) and the National Seismological Network (RSN: ICE-UCR), due to the size of the earthquake, volcanic structures can be affected. There is a rearrangement of material and even chemical changes.
At the Arenal, locals reported a noise characteristic of rolling boulders.” We know there is a cave in the north, in the direction of the community of La Palma,” said Maria Martinez geochemistry, OVSICORI. A team from this institution has visited the site and will release more information today.
“The most noticeable changes have been in its lagoon,” says Raul Mora, the RSN. “It looks much sulfur yellow spots on the lake, which is average at Poás before the earthquake but were not.”
The Turrialba volcano has reported a slight collapse, but “the bottom” of the colossus, rather than volcanic structure.” (However), the emission level is similar to what was observed previously,” said the expert OVSICORI. The RSN yesterday decided to install a seismological station between between that and the Irazu volcano.
Scientists have not yet visited the Rincon de la Vieja, but have received reports from neighbors about 17 miles west of the volcano, who claim that the normally crystalline water has a milky consistency apparently mixed with sulfur.
The neighbor also mentioned alleged cracks opened in the north, but that has not been confirmed. “We also know that, from time to time, there looms a steam plume. That happens from days before the earthquake,” explained Martinez.
“We know from experience in other countries that movements after more than 7 degrees of intensity there is the possibility that changes occur in the activity of volcanoes,” said Mora. “We’re not saying there’s a risk. What we say is that it is best to take the pulse investigate.”
Thanks to Wanda and John Reno for this link