Chapter 15 Mass Wasting:

The Work of Gravity

La Conchita, California

La Conchita, California

Landslide prone Coastal Community35,000 ya6,000 yaNumerous events in 1800’s19952005

SolutionRelocate residents

Mass Wasting

Downslope movement of rock/soilNeed slopeNeed gravity

Mass Wasting

Natural occurrenceProblematic when “we are in the way”Large scale events are rareTotal effects of small events are huge20-50 deaths in US annually$1-2 billion annually

Mass Wasting

Does this happen on Long Island?North Shore or South Shore? Increasing or decreasing on Long Island?

Earthquake creates landslide, India - 2005

Rain causes mudflow & buries town

Phillipines

Grand Canyon

Angle of Repose

Wildfires, California

Causes

Removal of vegetationVibrationIncrease slopeExcess moisture

Prevention

Remove excess moistureProvide vegetationMinimize slopeConstruct retaining wall

End of Chapter 15