Irazú Volcano could change soon and stop showing the emerald lagoon that causes so much attraction in its main crater, according to the Vulcanological and Seismological Observatory of Costa Rica (OVSICORI).

The phenomenon is due to three basic factors, explained expert Eliécer Duarte. The first one has to do with the falling materials from the walls of the crater, the second could be due to the wear suffered by the volcano since it is a very old formation, and the third one is the infiltration of water within the cone due to cracking.

Moreover, the water level is declining due to the lack of rain, since its primary source is of pluvial origin and the rainy season has been relatively dry during this period, due in part to the effects of El Niño phenomenon.
Duarte said that given these causes, none is related to a possible volcanic activity beyond what is normally presented by the colossus. The last eruption occurred in 1963, an activity that continued until 1965 and caused heavy economic losses and health effects to Central Valley residents, because of the huge volumes of ash released.

According to measurements made by the OVSICORI, Irazú lagoon, which temperature varies between 17 º and 19 º C, has had a stable deepness for many years but in 2001 reached 19 meters, and  in June this year it declined more than 10 meters. Currently it is estimated that its depth is less than 5 meters.

The Irazú is an active volcano with a long history of eruptions and eruptive cycles. It is an area of great hydrological importance since several rivers born there feed the river basins of the Chirripó, Reventazón, Sarapiquí and Great Tárcoles.

It has two craters, the “Principal” (Main), which is nearly circular and with highly inclined walls, measuring 1,050 meters in diameter and with 300 mts deepness; and the “Diego de la Haya” Crater, 600 meters in diameter and 100 meters deep. It has other smaller ones and an area of fumaroles.

Irazú Volcano is the highest in the country, with a height of 3,432 meters above sea level and it´s remarkable that on a clear day you can see from the top both the Pacific Ocean and the Caribbean sea, a great part of the Central Valley and even, with telescope, Nicaragua’s lake.