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Atrani, Amalfi Coast, Italy

Atrani, Amalfi Coast, Italy. Atrani After the Mudflow. Photo Credit: Flickr. Mudslide in California 2014. Landslides, Southern California. Photo Credit: USGS. Slumps. Images (c) 2002 and 2005 Andrew Alden, licensed to About, Inc. ( fair use policy ). Avalanches.

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Atrani, Amalfi Coast, Italy

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  1. Atrani, Amalfi Coast, Italy

  2. Atrani After the Mudflow Photo Credit: Flickr

  3. Mudslide in California 2014

  4. Landslides, Southern California Photo Credit: USGS

  5. Slumps Images (c) 2002 and 2005 Andrew Alden, licensed to About, Inc. (fair use policy)

  6. Avalanches Images (c) 2002 and 2005 Andrew Alden, licensed to About, Inc. (fair use policy) Photograph by Marc Muench/Getty Images: http://environment.nationalgeographic.com/environment/natural-disasters/avalanche-profile/?source=A-to-Z

  7. Rockslides Spectacular rock fall in Yosemite photographed by Herb Dunn on August 6, 2006. http://geology.com/articles/yosemite-rockfall-hazards/

  8. MASS MOVEMENTS

  9. Mass Movements • Downslope movement of soil & weathered rock by force of gravity • Climatic conditions determine extent of mass movements • Occur on slopes

  10. Mass Movements • Factors influence mass movements • Material’s weight • Material’s resistance to sliding or flowing • Depends on: (1) amount of friction, • (2) how cohesive the material is, • (3) anchored to bedrock or not • Trigger • Earthquake • Water • Rainfall increases weight of soil

  11. Types of Mass Movements • Creep • Slow, steady, downhill flow of loose, weathered Earth • Few cm per year • Noticeable over long periods of time • Causes trees to tilt, crack in walls

  12. Types of Mass Movements • Flows • Thick liquid • Move as slowly as few cm per year or hundreds of km per hour • Mudflows • Swiftly moving • Mixtures of water and mud • Triggered by earthquakes • Common in volcanic regions • Heat melts snow on slope & fills into spaces in sediment • Lahar • Occurs after a volcanic eruption • Semi-arid regions - intense rainfall, little vegetation

  13. Types of Mass Movements • Slides • Rapid • Occurs when a relatively thin block of soil, rock, & debris separates from the underlying bedrock • Landslide • Rockslide • Slump • Occurs from a landslide • Leave distinct crescent-shaped scars on hillsides

  14. Types of Mass Movements • Slides • Avalanches • Landslides with snow • Radiation from sun melts surface snow • Refreezes at night & turns icy • New snow falls & becomes heavy & slides • Slope between 30and 45 • Rockfalls • Rocks loosened by physical weathering processes • Freezing • Thawing • Plant growth

  15. Construction of buildings, roads, etc can make slopes unstable Trenches Divert water around slope Covering steep slopes w/steel nets Constructing fences along highways Retaining walls to support weakened slopes Education about building on slopes Mass Movements & Humans

  16. List possible locations of mass movements in our area & escape routes. Which regions of the world are mudslides more common?

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