Q COSTA RICA – Some of the ash released by the Poas Volcano in the past week included ‘juvenile magma”. This was confirmed by independent volcanologists Gino Gonzalez and Raul Mora, after analyzing samples of the material in the National Nanotechnology Laboratory (Lanotec), of the National High Technology Center (CeNAT).
The analyzed samples correspond to the eruptions that occurred on Wednesday, April 12 and Friday, April 14.
The experts explained that the volcanic eruptions this past week were generated from the interaction of magma and/or lava with the lagoon water in the active crater.
The interaction of water with juvenile magma is referred to as a Phreatomagmatic eruption, whereas phreatic or steam explosions simply involving hot rocks and water, and although magmatic heat is likely the source of the thermal energy in the reaction, the deposits do not contain juvenile magmatic material.
This analysis of the finding ratifies a presumption by specialists, that a pocket containing lava is pressing the hydrothermal system of the Poas volcano that has been rising towards the surface.
This would not be the first time that the Poas expels magma. The volcano spewed magma during the 1953 and 1955 eruptive period.
Experts at the Red Sismológica Nacional (RSN) and the Observatorio Vulcanológico y Sismológico de Costa Rica (Ovsicori), say they are still analyzing samples collected on Saturday following eruptions on Friday, when the colossus, at 7:57am, registered a major eruption in the last 64 years.
On Sunday, two eruptions did away with the crater’s ‘domo’ (volcanic dome), possibly causing a widening of the active crater’s lagoon, though experts say they have not been able to confirm such given the bad weather (atop the volcano).
Gino Gonzales of the Volcanes Sin Fronteras (Volcanos Without Borders), said that in the coming weeks we can expect similar eruptions like on Friday, when the plume of gas and has reached more than three kilometers above the crater.