The Costa Rica News (TCRN) – The outpouring of molten sulphur from the bottom of the lake of Poas Volcano – which floats in the colossus lagoon – is an event rarely recorded at volcanoes around the world, according to volcanologist of the National Seismological Network (RSN), Raul Mora.
Last Sunday, RSN volcanologists visited the crater of the Poas, which recorded an increase of the lake’s temperature by 10 degrees and also a decrease in its level.
“In the bottom of the lake, sulphur pools are formed, which is a fairly rare phenomenon. Sometimes they have a crust that does not allow the sulphur to reach the surface, but with increasing temperature, between 150° and 200°, this crust disappears and sulphur reaches the surface,” said Mora.
According to the volcanologist, the water activity is closely related to the decline of the lake´s level, as these events involve increased temperature, which generates an explosion. The water evaporates and a part of the water will be hurled out of the lake when the explosion occurs.
Regarding the level of the lake, Mora said that the current measurement is the lowest recorded since 1994, when it dried completely – as happened this Sunday, when the lake sank from 50 meters depth to just five.
A technical note given by the RSN on “extraordinary phreatic eruptions rich in sulphur of Poas,” notes that in recent months rainfall was low and formed structures indicating absence of moisture in the atmosphere.
The decline of the hot lagoon’s level until its possible disappearance, depends on the amount of rainfall during the rainy season of 2014, as well as whether Poas maintains its current activity.
The Costa Rica News (TCRN)
San Jose, Costa Rica