New Topic Today
Mass Movement = Mass Wasting
=colluvial processes
=slope processes
=slope failures
=LANDSLIDES
U.S. Landslide Risk
Which states have lots of landslide damage?
Landslides by U.S. Region
• California
• West Virginia
40% of U.S. damage
13% of U.S. damage
WV Has 1st or 2nd Highest
Landslide Damage Per Capita
• $100-300 /person/yr
• About Same as UTAH
Main Problems
Road Failures
Building Damage
Construction Cost Over-Runs
Strength of Slope =
Cohesion + Strength of Material
• Strength of Material Varies with
Moisture
• Poor Drainage: Slope Instability .
Angle of Repose
(Angle of Internal Friction)
Stable Angle of Slope for a Material .
Angle of
Repose
Sandstone
Sandstone
= 70-90°
Shale = 30°
(57% Slope)
}
30°
Shale
Sandstone
Shale
Angle of Repose
Sandstone = 80-90o
Shale = 30o or 57% Slope
Angle of Repose Landslide Deposits = 5-25o
~12o
Mount St. Helens debris avalanche deposits
Angle of Repose for Clay = 1 ° to 10°
~5o
Tully (New York) Landslide 1993 USGS Photo
See: USGS Fact Sheet 013-98 at http://pubs.usgs.gov/fs/fs13-98/
Shear Strength/Shear Stress
=Factor of Safety
Creep
Creep
Creep
Creep
Creep
Creep
Evidence of Creep
Landslides Rock
“Soil”
Debris
Earth
Type of Motion
Fall
Topple
Planar Slide
Rotational
Slide
Flow
Avalanche
Type of Motion
Landslides Rock
“Soil”
Debris
Earth
Debris Fall
Earth Fall
Fall
Rock Fall
Topple
Rock Topple Debris Topple Earth Topple
Planar Slide Rock Slide
Debris Slide
Earth Slide
Rotational
Slide
Rock Slump Debris Slump Earth Slump
Flow
Rock Flow
Debris Flow
Earth Flow
Avalanche
Rock
Avalanche
Debris
Avalanche
Earth
Avalanche
Basic Landslide Classification
Type of Motion
Material
“Soil”
Rock
Debris
Earth
Material
Rock: Bedrock
Soil: Unconsolidated Material
Debris: >20 % Big Stuff (>2 mm)
Earth: <20 % Big Stuff (>2 mm)
Landslides
Rock
“Soil”
Debris
Type of Motion
Fall
Topple
Planar Slide
Rotational
Slide
Flow
Avalanche
Earth
Landslides Rock
“Soil”
Type of Motion
Debris
Earth
Fall
Rock Fall
Debris Fall
Earth Fall
Topple
Rock Topple
Debris Topple Earth Topple
Planar Slide Rock Slide
Debris Slide
Earth Slide
Rotational
Slide
Rock Slump
Debris Slump
Earth Slump
Flow
Rock Flow
Debris Flow
Earth Flow
Avalanche
Rock Avalanche Debris Avalanche Earth Avalanche
Landslides
Fall
Landslides Topple
Topple
Rockslide at Yosemite
National Park, CA, kills 1,
injures 4 in 1999
Gerald F. Wieczorek, U.S.
Geological Survey and James B.
Snyder, National Park Service
http://landslides.usgs.gov/html_files
/landslides/Yosemite99.html
Photograph taken from across the
canyon by rock climber Lloyd
DeForrest while dangling on rope
2000 feet above the valley floor
Rock Fall
Yosemite NP
Rockfall Video
“Steinschlag” = Rock Fall - Gipfel Weißstein, Gries i.S., Tirol
http://www.youtube.com/watch?v=Tsf5NPLHQo4&feature=related
or
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Landslides - Rock Fall
Fall
70 ton Boulder: “Mon” Blvd., 10 March 1994
J.S. Kite Photo
“Mon” Blvd. Rock Fall, January 1983
Dominion Post Photo
Talus of Sandstone Boulders
Ice Mountain, WV
J.S. Kite Photo
Landslides Rock
“Soil”
Type of Motion
Debris
Earth
Fall
Rock Fall
Debris Fall
Earth Fall
Topple
Rock Topple
Debris Topple
Earth Topple
Planar Slide Rock Slide
Debris Slide
Earth Slide
Rotational
Slide
Rock Slump Debris Slump Earth Slump
Flow
Rock Flow
Avalanche
Rock Avalanche Debris Avalanche Earth Avalanche
Debris Flow
Earth Flow
Landslides
Planar Slide = “Slide”
Rotational Slide = “Slump”
Landslides
Planar Slide = “Slide”
Rotational Slide = “Slump”
Landslides
Planar Slide = “Slide”
Rotational Slide = “Slump”
“Slump”
Typical WV Landslide.
Slump scarp is at the head,
and earthflow is at the toe.
(Illustration by Paul Queen,
WV Geol. Surv.)
http://www.wvgs.wvnet.edu/
www/geohaz/geohaz3.htm
“Slump”
Earth Flow, Columbia Parkway, Cincinnati, Ohio.
http://landslides.usgs.gov/html_files/landslides/slides/landslideimages.htm
Earth Flow, US 52, Cincinnati, Ohio. Cincinnati:
highest per capita loss of any city in US.
(Photo by Aaron Mitten, Ohio Department of Transportation.)
http://www.theatlantic.com/issues/99jan/mud3.htm
Scarp formed at the head of a landslide in Penn Hills,
Allegheny County caused numerous problems for the
owner of this house.
http://www.dcnr.state.pa.us/topogeo/PhotoGallery/LandSli
de.htm
Penn Hills, Allegheny Co., Photo by John Harper, PaGS.
Zion National Park, Utah
USGS Landslide Images
http://landslides.usgs.gov/
html_files/landslides/slides/
landslideimages.htm
Two WMV files of Landslides
Package
2004 Landslide in Japan
http://www.youtube.com/watch?v=pJF-RhL4TvE
or
http://www.youtube.com/watch?v=ManGanavlL8&feature=related
Package
Sultan River Slide
http://www.youtube.com/watch?v=Qu88wb6gROg
Photo by Edwin L. Harp
U.S. Geological Survey
La Conchita Landslide
showing fractures in ridge
behind the scarp.
http://landslides.usgs.gov/html_
files/ElSalvador/figure4.html
Slump, La Conchita, California
2005 Debris Flow Killed 10
http://www.youtube.com/watch?v=W4KWxglDL3o
Geomorphic
Thresholds
• Intrinsic:
– e.g. collapse of cave
• Extrinsic:
– e.g. climate, humans
Real world geomorphic systems
not as simple as in the lab!
= the frustration = the attraction
of geomorphology
BIG
Slump,
New
River
Gorge
July 2001
Elverton Slump, New River Gorge, July 2001
Landslides Rock
“Soil”
Type of Motion
Debris
Earth
Fall
Rock Fall
Debris Fall
Earth Fall
Topple
Rock Topple
Debris Topple
Earth Topple
Planar Slide Rock Slide
Debris Slide
Earth Slide
Rotational
Slide
Debris Slump
Earth Slump
Rock Slump
Flow
Rock Flow Debris Flow Earth Flow
Avalanche
Rock
Avalanche
Debris
Avalanche
Earth
Avalanche
Las Colinas
Debris Slide-Flow,
Santa Tecla,
El Salvador,
13 Jan 2001
Earthquake
Source: Reuters, via
search.news.yahoo.com/
Las Colinas, El Salvador, Debris Slide-Flow (Reuters photo)
La Guaira, Venezuela: Dec 1999
La Guaira, Venezuela: Dec 1999 ~19,000 Dead
November 1985
Debris Flow Track,
Twin Run,
Pendleton Co., WV
Superelevation of Debris Flow, Twin Run
July 2001, Kanawha Valley, Glenn Ferris, WV
If you pictures or
video, see Dr. Kite
?
?
Kanawha City Debris Flow: 3 Dead 1973
Stopped Here 20 Feb 2003: Mt. St. Helens Lahar, 1982
Seattle
Mount Rainier, WA
Lahar
(= Debris Flow &
Debris Avalanche)
Hazard in the
Seattle Area
This Image:
http://vulcan.wr.usgs.gov/Imgs/J
pg/Rainier/Outreach/screen_pos
ter_lahar_haz.jpg
Wet-slab avalanche, Quandary Peak, Colorado
Colorado Avalanche Information Center photo by Pete Wynne
http://www.caic.state.co.us/photos.html
Avalanches Ride Almost
Frictionless on a Cushion
of Compressed Air
Battleship Avalanche Track,
February 28, 1987,
Red Mountain Pass,
Colorado
Colorado Avalanche
Information Center photo by
Tim Lane
http://www.caic.state.co.us/
photos.html
Rock “Avalanche” Video
Felssturz Einserkofel in Sexten, Freitag 12. Oktober
2007 - 60000 Kubikmeter Gestein brechen am
Einserkofel in Sexten Hochpustertal ab
http://www.youtube.com/watch?v=3jViIuA8xyI&NR=1
Mt. Huascaran, Peru, 1970
How Fast?
>300
km/h
17,000 dead
Armero, Colombia, near Nevado del Ruiz Volcano, Nov. 1985
23,000 Dead
Armero, Colombia, destroyed by lahar on November
13, 1985. More than 23,000 people were killed in
Armero when lahars (volcanic debris flows) swept
down from the erupting Nevado del Ruiz volcano.
http://vulcan.wr.usgs.gov/Volcanoes/Colombia/Ruiz/
description_eruption_lahar_1985.html
U.S. Landslide Risk
Type of Motion
Landslides Rock
“Soil”
Debris
Earth
Debris Fall
Earth Fall
Fall
Rock Fall
Topple
Rock Topple Debris Topple Earth Topple
Planar Slide Rock Slide
Debris Slide
Earth Slide
Rotational
Slide
Rock Slump Debris Slump Earth Slump
Flow
Rock Flow
Debris Flow
Earth Flow
Avalanche
Rock
Avalanche
Debris
Avalanche
Earth
Avalanche
WV Has 1st or 2nd Highest
Landslide Damage Per Capita
Main Problems Are
• Road Failures
• Building Damage
• Construction Cost Over-Runs
Retaining Wall Landslide Remediation
I-64, Afton Mountain, Virginia Blue Ridge.
http://www.mme.state.va.us/dmr/docs/hazard/slide.html
Regional Causes of Landslides
• Steep Topography
– Mountains
– Incision by Rivers
• Materials
– Red Shales - Expansive Clays
• Stupid or Ignorant People
– Oversteepening of Slopes
– Poor Drainage Management
– Lack of Geotechnical Consulting
Solutions to Landslide Problems
• Don’t Be Stupid – Use What
You Learn from GEOL 101
• Seek Geotechnical Help From
Geologists or Civil Engineers