The glacier-covered Volcan del Ruiz in Colombia has shown signs of renewed activity in the last several days, following a shallow earthquake of 3.0 on the Richter scale on June 22, associated with fracturing of rock within the volcano. The Colombian Geological Service recognized this fracturing as a sign of possible movements of magma that could lead to an eruption of lava. Tom Pfeiffer, a German volcanologist, suggested that the earthquake was “possibly caused by increased magma pressure inside the volcano’s upper storage system.”
Earlier this week, on June 27, the volcano released an ash cloud, reaching 1,800 meters above the summit. A second emission on June 28 attained a height of 850 meters. Its volume was sufficient to threaten aircraft in the region, which led to the sudden closure of the regional airport in Manizales, 25 kilometers to the northwest.
One local resident released alerts on Twitter, directing people to close windows and to wear face masks as protection against the ash. In a second tweet, included below, she indicated that the warning level had been raised from yellow to orange, “alerta naranja,” though official sources in the Colombian Geological Service and the regional Risk Management Unit wrote to assure the public that the warning level remained at yellow.
Alerta explosion en el volcan arenas nevado del ruiz hace 15 minutos.alerta naranja pic.twitter.com/wofG5FcLBs
— ANGELA (@abeta13) June 28, 2016
On its Facebook page, the regional Volcanic and Seismological Observatory released a video of the most recent eruption, taken on its webcam:
As GlacerHub explained in a recent post, the presence of glaciers on the volcano’s summit creates the risk of destructive debris flows known as lahars. The very rapid melting of ice caused by contact with molten lava can cause floods to rush down the mountain’s slopes, carrying large quantities of ash, rock and soil to populated areas. An eruption of the volcano in 1985 led to over 23,000 deaths.
The Colombian authorities and local citizens are monitoring this situation closely. If an eruption is likely, the municipalities in the region will receive warnings. GlacierHub will report on any significant intensification of the volcano’s activity.