Mass Wasting
By : Alyanna Sharyce D. Aparilla
geo1.tcu.edu
Mass Wasting
• mass movement or slope movement
• large movement
• rock, soil and debris
• force of gravity
• changes mountain
• suddenly or slowly over time
• landslide
geo1.tcu.edu
Role of mass wasting
•maintains the slopes
•shapes the landscape
geo1.tcu.edu
Slopes change through time
Modification of slope either by humans or by natural
causes can result in changing the slope angle so that it is
no longer at the angle of repose. A mass-wasting event
can then restore the slope to its angle of repose.
geo1.tcu.edu
Role of water
increase according form a pile with a
Dry
Slightly wet
Saturated
with water
to grain size but
slope angle of
usually 30 and 37
repose
high
hold in place
low
flow like liquid
geo1.tcu.edu
Over steepened slopes
•Slope steepness
•Gravitational force
•Increased steepness
•more mass wasting
•Angle of repose
- steepest angle
- unconsolidated grains
- stable
- frictional contact
geo1.tcu.edu
Removal of vegetation
•Prone to mass wasting
• vegetation stablelizes soil
particles on the surface
• anchors soil under the
surface
cbsnews.com
Blog.savemaumee.org
Earthquakes
•Violent shaking
• sections of mountain or
• hills
• slide down
• slope
Mass Wasting
Type of Motion
Fall
OR
Rate of Movement
Rapid
Slump
Rockslides & Slumps
Flow
Slow
Creep
Rockslide
Solifluction
Debris flow
Permafrost
Earth flow
geo1.tcu.edu
Fall
• rock or debris
• steep slope
• dislodged
• falls
• down the slope
• single or mass
• collision
nature.nps.gov
Rock fall in Mayon volcano
•142 volcanic earthquakes
•251 rockfall events in the past 24 hours
•Updated September 19, 2014 - 12:00am
philstar.com
Rockslide
•Travel a long way
• source initial fall
• rapid
• down slope movements
• bedding plane, joint or area of weakness
• break up
•Large pieces collide
Rockslide on Marcos highway
Slump
•slides
• downward rotation
•rock or regolith
•curved surface.
•upper surface undisturbed,
•arcuate scars or depressions .
• Heavy rains or earthquakes
alevelgeography.com
Liquefaction
Liquefaction is a phenomenon in which
the strength and stiffness of a soil is
reduced by earthquake shaking or other
rapid loading.
www.youtube.com
Debris Flow
• debris
• rain water
• slope material
• freshly burned land
• Chapparral land
• rapid
• Fast flowing river concrete
• most dangerous
• car sized boulders
Sentinel Asia and CNES
Lahar
•thaw caused by volcanic eruption
•mud
• ash
•hot water
http://pubs.usgs.gov/
Mudflows
•highly fluid
•high velocity
• sediment and water
•consistency of wet concrete
•heavy rains
•unconsolidated sediment
volcanoes.usgs.gov
Lahar after Mt. Pinatubo eruption
•Lourdes
•15 miles northeast of
Mount Pinatubo
•lahars
•June 1991
•100,000 + people
destroyed
http://pubs.usgs.gov/
Earth flow
•heavy rains
•Velocities: 110s of m/day
•active for long periods of time
•narrow tongue-like features
•scarp or small cliff
Debris Flow
•Barangays Andap and Cabinuangan in New Bataan, Compostela Valley.
•Boulder-rich debris flow field (red)
•sandy deposits (tan).
•7 kilometers long.
Sentinel Asia and CNES
Soil creep
• slow
•Soil and rocks
•Gravity
• farther down the slope
• freeze or thaw
•Bulges in the soil
http://sageography.myschoolstuff.co.za/
Solifluction
• cold polar regions
• high mountains
•melted water, regolith and upper layer of soil
• slips over the ground
ngee-arctic.blogspot.com
Permafrost
• layer of groundwater
•fills spaces
• soil and rock
• permanently frozen
http://blogs.edf.org/
REF:
http://www3.geosc.psu.edu/~jte2/geosc20/lect10.html
https://www.youtube.com/watch?v=WyGw1pk9YWo
http://geogrify.net/GEO1/Images/FOPG/1226a.jpg
http://sageography.myschoolstuff.co.za/wp-content/uploads/sites/2/2013/01/creep2.jpg
http://cnnphilippines.com/regional/2015/07/19/Marcos-Highway-closed-rock-slide.html
http://opinion.inquirer.net/46563/how-debris-buried-compostela-village
http://www.philstar.com/headlines/2014/09/19/1370755/lahar-warning-aroundmayon
http://pubs.usgs.gov/fs/1997/fs114-97/
http://hyperphysics.phy-astr.gsu.edu/hbase/geophys/wasting.html
(http://study.com/academy/lesson/mass-wasting-definition-types-causesprocesses.html)
(http://earthsci.org/flooding/unit3/u3-0203.html)
http://www.ce.washington.edu/~liquefaction/
html/what/what1.html
Mass Wasting
Type of Motion
Fall
OR
Rate of Movement
Rapid
Slump
Rockslides & Slumps
Flow
Slow
Creep
Rockslide
Solifluction
Debris flow
Permafrost
Earth flow
geo1.tcu.edu