The Rincón de la Vieja Volcano in Guanacaste registered unexpected activity this Tuesday at 10:20 a.m. with a phreatic eruption (steam and water) that elevated 400 meters over the crater, reported the National University’s Volcanology and Seismology Research Institute.

The short eruption lasted under two minutes, but neighbors mentioned hearing a sound similar to a jet’s engine; material (mud, water and rocks) sled down the north slope of the volcano from the hyper-acid crater lake for approximately 15 minutes, there are no reports of any damages in the neighboring sites, though the Pénjamo and Azufrado rivers increased their water level and turned grey colored as a result of the material that fell into the water.

Rincón de la Vieja is one of Costa Rica’s active volcanoes, and although it goes through dormant periods, the phreatic activity has been increasing since 2015. One of the most recent eruptions this volcano registered was back in March of 2016 when the column of gas and vapor reached 700 meters above the crater.

Rincón de la Vieja, joins Poás and Turrialba in the list of volcanoes that have shown strong activity in the last few months. Experts are keeping their eyes in each of these, but they are quick to mention that even though it is unusual to have three volcanoes erupting the behavior of the volcanoes is normal and currently does not represent any danger to the population.