Publish emergency evacuation routes. What to Do During a Volcanic Eruption Be prepared for the hazards that can accompany volcanic eruptions, and know how to respond to reduce risk. Hot ash or lava from a volcanic eruption can rapidly melt snow and ice at the summit of a volcano. The melted water quickly mixes with falling ash, with soil cover on lower slopes, and with debris in its path. This turbulent mixture is dangerous in stream channels and can travel more than 50 miles away from a volcano.
Intense rainfall can erode fresh volcanic deposits to form large mudflows.
If you see the water level of a stream begin to rise, quickly move to high ground. If a mudflow is approaching or passes a bridge, stay away from the bridge. Landslides and rockfalls. Ashfall and acid rain. Follow the evacuation order issued by authorities and put your disaster plan into action.