On April the 23rd, the Poás Volcano eruption spat out incandescent rocks for the first time in decades; it has also registered some smaller eruptions throughout the whole week
Volcán Poás. 19 de abril 2017. Videos por Carlos Sánchez y Geoffroy Avard. OVSICORI
Posted by OVSICORI-UNA on Wednesday, April 19, 2017
Specialists have been studying the recent activity of the Volcano, where they can confirm the existence of magma in 5% of the materials that were erupted, which is a sign that the recent activity is just the start of a longer active phase, which may lead to more violent eruptions that the ones registered so far. The particles expelled by the volcano are, as per the volcanologists, mostly secondary minerals, preexistent rocks and juvenile material.
Volcanologist of Volcanes sin Fronteras, Gino González, explained that the small quantities of magma which are making their way inside the volcano, making the volcano more “explosive.”This magma has been combined with the water of the lake, and it has been causing the eruptions of the last few days. These types of activities are referred to as phreatomagmatic eruptions or magmatic.”
The report, provided by Volcanes sin Fronteras, shows that these types of eruptions have not happened since 1955, and the violent eruptions generated by the magma may get to an altitude of 5 kilometers. ¨It´s like having a pan with hot oil and adding some drops of water to it¨ as said by González in an interview with local news site CRHOY.
The volcanologists cannot predict how long this activity period will be; this may last for weeks’ or maybe months. And the National University Volcanology and Seismology Research Institute (OVSICORI) answered some of the most common questions regarding this situation;
Q/ Could Poás Volcano eruption have lava eruptions and if so which areas could be affected?
A/ The main dangers associated with an active volcano refer to lahars (a type of mudflow, see video below) and pyroclastic flow (a fast-moving current of hot gas above 100°C and volcanic matter) which would be limited to the areas very close to the crater and of slow advance. This is why strict vigilance is kept over the rivers
Q/ Could this cause earthquake?
A/ The seismic signals that originate in volcanic areas are particular of each volcano; the activity usually presents very small earthquakes produced by the movement of magma and the gas pressure inside the volcano. These earthquakes are very small and local.
Q/ Will the activity at Poás Volcano affect San José?
A/ The Poas Volcano eruption practically will not affect the metropolitan area, in the event of ash-fall this is distributed by the wind and the direction of the winds will take it to the areas of Naranjo, Sarchí, and Grecia. (Check map above)
News.co.cr. (2017, 19 April 2017). What You Need to Know About Poas Volcano Eruption – Costa Rica – Costa Rica Star News. [Weblog]. Retrieved 24 April 2017, from https://news.co.cr/what-you-need-to-know-about-poas-volcano-eruptions-costa-rica/59625/