Sinabung roars – largest pyroclastic flows, thick ash layer, major hazard from lahars

The eruption of Indonesian Sinabung volcano intensified again today and produced pyroclastic flows reaching more than 5 – 6 km in length, the largest so far. Associated ash plumes rose to approximate altitude of 8 km (25 000 ft).

Yesterday, the official number of refugees was 25 810, from a total of 8 040 households. 

Volcano Discovery reported today that it seems the previous dome which grew at the summit of Sinabung, collapsed a few days ago, leaving a large crater breached on the side where the earlier pyroclastic flows had gone down. "The temporary absence of a lava dome in the past days led to the cessation of pyroclastic flows. Now, the new dome has again surpassed the boundary of the breach and sheds pyroclastic flows into the deep ravine below (Thanks to B. Behncke for the comment).

On the other hand, a strong increase in SO2 emissions and hybrid earthquakes indicate that a larger new batch of new magma has risen, which also explains the new more vigorous activity."

Mount Sinabung on January 14, 2013. Video courtesy: Volcano Discovery

With the likely heavy rains in the weeks ahead, another major hazard will come from lahars – mud flows of remobilized loose ash. Lahars can be extremely destructive.

In addition, 8 – 10 cm thick ash layer covering the vast area around the volcano is causing major damage and logistic difficulties (muddy and impassable roads).

Featured image: CCTV / Volcano Discovery