Four volcanoes were closely being monitored by officials today following the 7.6 earthquake in Costa Rica this past week. Now Reuters is reporting that Nicaragua’s tallest volcano discharged an ash cloud nearly a mile into the atmosphere on Saturday, prompting the evacuation of thousands of nearby residents who heard explosions emanating from its crater.
There were no immediate reports of injuries or damage, authorities said.
The 5,725-foot (1,745-meter) San Cristobal volcano, located about 95 miles (150 km) north of the capital Managua in the country’s volcano-dotted northwest, has been active in recent years, and stirred in mid-2008, when it expelled gas and rumbled with a series of small eruptions.
The government expects to evacuate about 3,000 people from around San Cristobal, though numerous families already have done so on their own, said Guillermo Gonzalez, who heads Sinapred, a government emergency and disaster relief agency.
“We already have nearly the entire apparatus underway,” Gonzalez said. “A response plan exists for volcano eruptions and every community has clearly defined places for people to go to once they are evacuated,” he said.
A gas and ash plume stretched between 2 and 2 1/2 miles (3.5 and 4 km) into the atmosphere, Gonzalez said. The Nicaraguan Institute of Territorial Studies, which monitors the country’s volcanoes, said in a preliminary report that “more gas emissions and sporadic explosions” could be expected from San Cristobal.
The volcano is one of the most active along Nicaragua’s Pacific coast, according to the institute, and often averages nearly 100 daily seismic movements.
Government spokeswoman Rosario Murillo earlier said authorities were still assessing the strength of the volcanic activity. As many as 20,000 people could ultimately be affected, she said.
When seeing the after effects of the earthquake in Costa Rica this past week, one thing that officials were closely watching were the active volcanoes within the country. Even a small shift under one of these giants could cause an eruption. At least four of the seven active volcanoes in the country are in the crosshairs of scientists after the earthquake of 7.6magnitude occurred on Wednesday in Costa Rica. These are Arenal (Alajuela), Rincon de la Vieja (Guanacaste), Turrialba (Cartago) and Poás (Alajuela).
According to specialists from 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, it is normal that volcanic structures, especially those already vulnerable, are affected. There is a rearrangement of material and even chemical changes.
The clearest example is the Arenal, where 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 of this institution made field visit to the site and will release more information today.
“In the Poas, how little we could see, the rangers (by weather), report no noticeable landslides and cracks,” he added. However, Raul Mora, the RSN, ensures that the most noticeable changes have been in its lagoon. There are many more yellow sulfur spots on the lake now at Poás than were there before the earthquake.
The Turrialba volcano has reported a slight collapse, but “the bottom” of the colossus, rather than volcanic structure. The emission level is similar to what was observed previously,” said the expert OVSICORI.
Because there have been earthquakes there, the RSN yesterday decided to install a seismological station between that and the Irazu volcano. This is done because in the medium term, it is uncertain whether the earthquakes that occur there (as replicas) are the result of a tectonic event or a volcano itself.
Scientists have not yet visited the Rincon de la Vieja, but have received reports from neighbors (who live about 17 miles west of the volcano), who claim that the crystalline water normally received from a nascent nearby nature has a milky consistency apparently mixed with sulfur. “He also mentioned alleged cracks opened in the north, but we have not confirmed. We also know that, from time to time, there looms a steam plume. That happens from days before the earthquake,” explained Martinez.
The potential of the San Cristobal volcano erupting has come as a surprise to specialists simply because of its proximity to the earthquakes epicenter.
Contributor D. Chandler