April 28th, 2014 (InsideCostaRica.com) Costa Rica’s iconic Arenal Volcano, which has been essentially inactive since 2010, could continue its slumber for hundreds of years – or explode in a violent eruption – according to an expert at the Volcanological and Seismological Observatory of Costa Rica.
“The volcano could remain in a dormant state for a long period of time as it has [in the historical record]. It could remain dormant for 600 or 800 years, or it could reactivate in an explosion such as in 1968. It all depends on internal conditions of the volcano that we cannot see,” said volcanologist Javier Pacheco.
Arenal at one point had been believed to be a dormant volcano, prior to a sudden and violent eruption on July 29th, 1968. The eruptions continued unabated for several days, burying over 15 square kilometers with rocks, lava and ash. When over, the eruptions had killed 87 people and buried the villages of Tabacón, Pueblo Nuevo and San Luis. During the most violent explosions, the volcano flung giant rocks weighing several tons more than a kilometer away at a speed of 600 meters per second.
The volcano remained active until 2010, transforming the area into one of the country’s most popular tourist destinations.
Pacheco said Arenal seems to be deepening its sleep the last few years. “For example, there are no carbon dioxide emissions in the amounts seen before, in fact they cannot even be measured as they are below what our measurement devices can detect,” Pacheco said, adding that there is almost no seismic activity at the volcano.
While Pacheco says the volcano could remain dormant for hundreds of years, “This could be reversed at any time by a new magmatic intrusion,” he said.