Increase in eruptive activity.
Sangay volcano, located on the southeast flank of the Cordillera Real, is one of the most active eruptive centers of Ecuador. He recorded a constant activity since 1628 (Hall, 1977). The Geophysical Institute maintains a permanent monitoring of the volcano, to identify periods of crisis presented by the Sangay. In previous periods, by overflights, it was found that during the eruptive phases, its common type of strombolian activity was characterized by the emission of lava flows, pyroclastic flows, lava domes and emissions of gas and ash columns that generally fail to affect populated areas.
Last activity period of the Sangay began in January 2015, which lasted until mid-April 2015. During this period, there were two small lava flows reached several hundred meters below the level of the crater central. There had also been eruptive columns that were recorded with a moderate load of ash, which did not reach inhabited areas.
After this eruptive episode, the internal and surface activity of the volcano area was returned to its base level until March 5, 2016 when he began recording sporadic seismic events.
However, it should be noted that from the 8 and 9 March, the seismicity is much larger, with the presence of long period events (February 31 and March 9), some tectonic volcanic earthquakes and signs of small explosions (11 since March 7), as well as small episodes of tremor.
On the other hand, the NOAA satellite images show a thermal anomaly today, with an emission at 02h05TL, heading south.
With this new anomaly, it is necessary to maintain constant surveillance, especially because of the presence of emission columns that on the one hand can reach populated areas, depending on the wind direction and on other hand can disturb air traffic.
It is important to note that it is not appropriate to get on the volcano during the duration of this abnormality.
March 10, 2016. Sangay, Ecuador :
Source : IGEPN
Ecole nationale polytechnique
Photo : National geographic