Following five months of relative calm, the Turrialba volcano has awakened with an intensity that has not been recorded in more than a century. It all started on Sunday, March 8^th with a phreatic (ground water) eruption that would later include exhalations of gas and ash. Two late-night eruptions on Wednesday resulted in moderate ash columns, but the most spectacular events took place on Thursday.

The first eruption on Thursday lasted about six minutes and left several communities in the Central Valley covered in volcanic ash. The second eruption lasted 23 minutes and produced an ash column that reached 1,000 meters in height, which prompted the Directorate of Civil Aviation to issue a warning with regard to possible flight interference. Yet another ash eruption would take place around 2:50 pm; by this time, the National Commission on Emergencies had issued a yellow alert, which included evacuations of residents, domestic animals and livestock from communities that lie on the skirts of the volcano.

Ten schools located in the vicinity of the Turrialba have been closed until further notice. Costa Rica’s main airport, the Juan Santamaria International Airport (SJO) in Alajuela shut down flight operations until 8:00 am on Friday. A smaller airport, the Tobias Bolaños in Pavas was also shut down.

Officials from the National System of Nature Conservation observed the last two eruptions from about two kilometers away and were completely covered in ash. They reported loud explosion sounds and rocks flying out at great velocity. Volcanologists from the National Seismology Network of the University of Costa Rica detected slight seismicity at the Turrialba with each eruption; however, they have not been able to ascertain the presence of magma.

Geologists monitoring the Turrialba are not certain about the amount of energy that the colossus may store at this time. They are hoping that these recent eruptions result in stability, but they cannot predict if events of greater intensity may occur today or during the weekend. Teams of geologists and volcanologists are preparing to climb to the crater as soon as they deem it is relatively safe to do so.

Emergency officials have warned the population in Costa Rica to protect electronic equipment from the volcanic ash and to keep a face mask handy in case breathing becomes difficult, particularly for those who suffer from asthma.

Source: CRHoy.com