Using a drone a group of volcanologists calling themselves Volcanes sin Fronteras (Volcanos Without Borders) were able to give us impressive photos and video of the Turrialba volcano.
The photos were taken in December 2017 and first two weeks of January 2018, during several inspections of the Colossus.
The volcanologists said they were there to work on the newly ejected ash samples, as well as to perform measurements of the activity of the active crater.
On their Facebook page, they posted: “The activity is dominated by intense degassing in the active crater, with sporadic explosions every 30 minutes to an hour. During these (eruptions) fumes and particles of ash are released which reach heights above 300 meters above the crater. In the field, a series of volcanic deposits, Phreatomagmatic-Estrombolianos, generated from October 2014 to date, is clearly observed. In our visits, we saw several explosions of surface origin, with a camera installed in an unmanned aerial vehicle (drone)”.
Using the drone, the volcanologists said they were able to observe at a depth close to 250 meters from the southeast edge of the active crater. There they were able to determine that the inner walls of the southwest crater exhibit slopes that surpass an inclination of 55 degrees and that gives the mouth of the volcano a depth of 126 meters, that is, it is 1.5 times the height of the Banco Nacional building in San Jose, which measures 82 meters high.
The crater measures 69,000 square meters, that is, it covers an area a little larger than the Estadio Nacional (National Stadium) in La Sabana, and that in the background there is an internal crater that measures 189 meters wide from where volcanic materials are emitted such as ash, pyroclastics (fragments of magma) and gases.
“In terms of volcanology, it can be said that the (Turrialba) volcano is an open vent system or open system, where the activity is dominated by the system. In addition, the heat and pressure source is close to the surface, this could generate larger eruptions in a short term. We consider the second hypothesis to be the strongest,” said Volcanes Sin Fronteras.
Through a series of photographs posted on Facebook on Thursday, it is possible to observe the reflection of the filament in the gases released in the upper part of the crater. This type of phenomenon is known in Japan as Gojinka (Japanese Fire God).
“That means that the source of heat and pressure is close to the surface and this could generate larger eruptions in a short time,” said one of the volcanologists of the organization, Gino González Ilama.
The Turrialba volcano, which remained at dormant for years, began in 1996 to show signs of greater activity, but it was not until 2007 that it began to become intense.
After 146 years of calm, it made its first major eruption on January 5, 2010, and then, by an internal force, two new conduits were opened on the southwest wall. Subsequently, the Turrialba continued with cycles of annual eruptions in 2011, 2012 and 2013.
For the experts, October 29, 2014, marked the start of a much more constant activity of the volcano. That day there was an eruption that lasted 13 hours and ended with a very strong emanation of 25 minutes. From that moment, the annual eruptions went through cycles with intervals of 2 or 3 months of relative calm, a situation that has remained until today.
Not to let us forget about it, last Monday, January 15, at dawn, the Turrialba erupted strongly, confirmed by the Observatorio Vulcanológico y Sismológico Nacional (Ovsicori) and the Red Sismológica Nacional (RSN). The emanation reached a distance of 12 kilometers from the crater, which makes it presume that the column could have reached a height of a kilometer and a half to two kilometers. Due to the bad weather prevailing in the country on Monday, that eruption could not be appreciated.
