By Natalia Rueda 
Colombia’s Nevado del Ruiz volcano has had its alert level downgraded from orange to yellow, following the gradual decrease in several of the parameters, according to the Colombian Geological Service (SGC).
The SGC said the move from orange to yellow indicates “an unstable behavior in which increases in seismic activity and manifestations on the surface are contemplated.” At the same time, they warned that the volcano can quickly destabilize, and urged people to pay close attention to its evolution.
Situated between the border of the departments of Caldas and Tolima, Nevado del Ruiz is a stratovolcano and one of the most dangerous volcanoes in South America due to the population of more than half a million people living nearby.
The level was upgraded to orange in April due to the increase of seismic activity which accompanied the typical tectonic seismicity and internal signals of the volcano. This was followed by the SGC instituting a strict monitoring protocol, which included weekly and monthly reports.
As of Tuesday the alert level has returned to yellow, though the SGC warns that volcanic activity cannot be predicted, and therefore urged caution given the volcano could become unstable once again.