Tuesday's heavy rain around Mount Kelut brought attention to increasing threat of lahars, destructive mud flows composed of a slurry of pyroclastic material, rocky debris, and water.
Lahars can flow tens of metres per second, be 140 metres (460 ft) deep, and destroy any structures in their path. Notable lahars include those at Nevado del Ruiz and Mount Pinatubo, each of which killed thousands of people.
The first lahars around Mount Kelud have already appeared during the past days, and produced extensive additional damages.
A small bridge and 2 houses were swept away from the river Sambong. A mosque and several other houses were also destroyed in the district of Kediri. A person had to be rescued when trapped on an island surrounded by fresh mud flows. There are no reports of casualties.
VolcanoDiscovery correspondent Aris sent pictures showing the devastation caused by ash deposits and lahars.
"Aris also reports that the eruption did not affect the southern slope of Kelut, where no damage occurred ("nothing happend .. all green"). The worst-hit villages are Puncu (Kediri Regency) to the NW and Pandan Sari to the north (Malang Regency)."
Kali Code in Yogyakarta (200 km west of Mount Kelut), and the nearby homes, during the 2014 eruption of Kelud. February 14, 2014. Author: Crisco 1492
Featured image: Kali Code in Yogyakarta, and the nearby homes, during the 2014 eruption of Kelud. Author: Crisco 1492