The flowing slurry may consume additional water through melting of snow and ice or by engulfing river or lake water. ... Voluminous lahars commonly grow to more than 10 times their initial size as they move downslope.

How far can a lahar travel?

On steep slopes, lahar speeds can exceed 200 kilometres per hour (120 mph). With the potential to flow distances of more than 300 kilometres (190 mi), a lahar can cause catastrophic destruction in its path.

Can you outrun a lahar?

A lahar moving down a channel near Santiaguito in Guatemala in 1989. ... They are thick like concrete but can move in a channel at speeds up to 30 mph (67 km/hr) depending on the steepness of the slopes, so you aren't outrunning or even outsprinting a lahar.