Because water acts as a lubricant, mudflows travel farther than avalanches. Both avalanches and mudflows can move very fast. Mudflows move downslope and into stream valleys. Being able to forecast the path of mudflows is important to scientists who assess the potential hazards of volcanic eruptions. The chief threat to people is burial.
Structures are at risk of being buried, carried away, or collapsing.
Place a tarp over the newspapers. Make sure the tarp is large enough to simulate a flat area at the volcano's base. For ideas, refer to the photographs on the poster and to the topographic map on Activity Sheet 4.1b. Place bricks, rocks, or tent stakes around the base of the tarp to keep it from moving. Tell students that they will be creating an avalanche.