Topic: Erosion & Mass Movement - T-Birds Earth...
Transcript of Topic: Erosion & Mass Movement - T-Birds Earth...
Topic: Erosion & Mass Movement
Erosion moving sediments from one
location to another.
Gravity
FORCE behind all erosion.
Mrs. Burns in
between two fallen
rock boulders at
Niagara Glen
Burns 2007
Talus pile, Niagara Glen Burns 2007
Mount Rushmore
Frost Wedging and Talus Cones
Agents of Erosion (things that move
sediments)
Water
Wind
Ice (Glaciers)
Mass Movement
• Large section of land and/or snow moved by
gravity
Ex) landslide, soil creep, avalanches, mudslides
Landslide
Landslide in California
Major landslide hits homes in Southern California
A firefighter surveys damage caused by a mudslide that destroyed 15 homes in La Conchita, Calif.
http://www.youtube.com/watch?v=mknStAMi
a0Q
Creep
The top of the soil layer moves faster
than the soil beneath, causing the
young trees to bend down slope. As
the roots stabilize the soil, creep is
greatly diminished and the trees can
then grow straight.
The slow down slope movement of erosional debris has displaced
(arrow) a gas pipeline in northern British Columbia. Original position of
pipeline is indicated by white dashed line. The pipeline has been placed
on timbers to allow adjustment to continuing slope movement.
Photographer: L.D. Dyke, 2006
Avalanches
LOOSE SNOW
AVALANCHES
SLAB AVALANCHES
Involve motion of cohesive layer above a weak failure layer
Cohesive layer becomes an avalanche when cut around all its boundaries
by brittle fractures
Massive avalanche just
outside of Denver, CO, on
1/6/2007
200 ft wide & 15 feet deep
Mudflow
Mudflow-damaged house along the Toutle River, Washington. The height of the mudflow
is shown by the "bathtub-ring" mudlines seen on the tree trunks and the house itself
(Photograph by Dwight Crandell).
04:01 PM PST on Tuesday, December 18, 2007
Landslides on tracts clear cut by Oregon State University's College of Forestry
set into motion the flow of mud and debris that inundated homes and U.S. 30,
geologists and foresters say.
FQ:
What is the very slow movement of rock downhill called?