More than six years after its eruptive period, the Turrialba volcano seems unwilling to stop. Last week, a new eruptive cycle began with the emission of ash and an increased seismic activity.
This is indicated by volcanologists, Dr. Mauricio Mora Fernandez and Dr. Guillermo Alvarado Induni, from the National Seismological Network (RSN), formed by the University of Costa Rica (UCR) and the Costa Rican Electricity Institute (ICE) .
According to experts, between November 2015 and early January 2016, the Turrialba volcanoes presented eruptions isolated, in a context of low seismicity. From January 10 until mid-March there has been an increase in seismic activity (such as tremor and volcanic earthquakes). After this period, the level of tremor decreased and we began recording sismo -volcanics events.
In April not less than three swarms of volcano-tectonic earthquakes between Turrialba and Irazu volcano took place. On April 29 from 16.00 has initiated another tremor, which gradually increased in magnitude until about 3:00 Saturday, April 30, and began issuing ashes, which persisted for most of the day.
This process marked the beginning of a new eruptive cycle with about three eruptions per hour, which fell during the day on 3 May.
The eruptions were moderate to low, with ash columns up to about 500 to 1000 meters above the crater, with expulsion of block limited to the area of the active crater and pyroclastic clouds (burning) under 200 meters long.
During the days of Sunday 1 and Monday 2 May the ashes were moved to the south by the prevailing winds, and were diluted in the Central Valley, which generated a strong smell of “sulfur” (H2S) in the cities of Tres Ríos and Curridabat. Even the smell was detected in several international flights at 6 Kilometres nearest. During May 3, the wind direction was to the Caribbean.
During that year, minor ash emissions occurred on 3, 6, 7, 8 and 30 January and 2, 6, 7 and 8 February.
After 79 day of break in the ash emissions, this eruptive activity began on April 30, being similar to those of January 2010 and the end of October / early November 2015.
However, this activity differs in the type of seismic signals and the speed of their energy processes, which disappeared suddenly at the end of April and the level of the recorded seismic activity that has developed.
” The volume of the material ejected does not match the injection accumulated in the deep, showing that the Turrialba still has potential to continue its activity and even generate much more explosive eruptions,” concluded volcanologists.
May 04 , 2016.Turrialba , Costa Rica ,
Source : ucr.ac.cr
Photo : Ovsicori