u.s. landslide risk

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 40% of U.S. damage• West Virginia 13% of U.S. damage

WV Has 1st or 2nd Highest Landslide Damage Per Capita

Main Problems Road FailuresBuilding DamageConstruction Cost Over-Runs

• $100-300 /person/yr• About Same as UTAH

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= 70-90°

Shale = 30°(57% Slope)

Sandstone

Shale

}30°

Angle of ReposeSandstone = 80-90o

Shale = 30o or 57% Slope

Sandstone

Shale

Angle of Repose Landslide Deposits = 5-25o

~12o

Mount St. Helens debris avalanche deposits

Angle of Repose for Clay = 1 ° to 10°

Tully (New York) Landslide 1993 USGS PhotoSee: USGS Fact Sheet 013-98 at http://pubs.usgs.gov/fs/fs13-98/

~5o

Shear Strength/Shear Stress

=Factor of Safety

Creep

Creep

Creep

Creep

Creep

Creep

Evidence of Creep

“Soil”Debris Earth

Rock

Typ

e of

Mot

ion

Fall

Topple

Flow

Avalanche

Landslides

Planar Slide

RotationalSlide


Rock

Typ

e of

Mot

ion

Fall

Topple

Planar Slide

RotationalSlide

Flow

Avalanche

Rock Fall Debris Fall Earth Fall

Rock Topple Debris Topple Earth Topple

Rock Slide Debris Slide Earth Slide

Rock Slump Debris Slump Earth Slump

Rock Flow Debris Flow Earth Flow

Rock Avalanche

Debris Avalanche

Earth Avalanche

Landslides

Basic Landslide Classification

Material

“Soil”

Debris EarthRock

Typ

e of

Mot

ion

Material

Soil: Unconsolidated MaterialDebris: >20 % Big Stuff (>2 mm)

Earth: <20 % Big Stuff (>2 mm)

Rock: Bedrock


Rock

Type

of M

otio

n

Fall

Topple

Planar SlideRotationalSlide

Flow

Avalanche

Landslides


Rock

Typ

e of

Mot

ion

Fall

Topple

Planar Slide

RotationalSlide

Flow

Avalanche






Rock Avalanche Debris Avalanche Earth Avalanche

Landslides

Fall

Topple

Fall Topple

Landslides

Landslides -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 FallYosemite NP

Rockfall Video“Steinschlag” = Rock Fall - Gipfel Weißstein, Gries i.S., Tirolhttp://www.youtube.com/watch?v=Tsf5NPLHQo4&feature=related

Image Not for Image Not for

Web PostingWeb Posting

Fall

Landslides - Rock Fall

70 ton Boulder: “Mon” Blvd., 10 March 1994

J.S. Kite Photo

“Mon” Blvd. Rock Fall, January 1983Dominion Post Photo

Talus of Sandstone BouldersIce Mountain, WV

J.S. Kite Photo


Rock

Typ

e of

Mot

ion

Fall

Topple

Planar Slide

RotationalSlide

Flow

Avalanche






Rock Avalanche Debris Avalanche Earth Avalanche

Landslides

Planar Slide

RotationalSlide

Planar Slide = “Slide”

Rotational Slide = “Slump”

Landslides



Landslides



Landslides

“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.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/LandSlide.htm

Penn Hills, Allegheny Co., Photo by John Harper, PaGS.

Zion National Park, UtahUSGS Landslide Imageshttp://landslides.usgs.gov/html_files/landslides/slides/landslideimages.htm

Two WMV files of LandslidesPackage

Package

2004 Landslide in Japanhttp://www.youtube.com/watch?v=pJF-RhL4TvE

orhttp://www.youtube.com/watch?v=ManGanavlL8&feature=related

Sultan River Slide http://www.youtube.com/watch?v=Qu88wb6gROg

Photo by Edwin L. HarpU.S. Geological Survey

La Conchita Landslideshowing 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

BIGSlump, New River Gorge

July 2001

Elverton Slump, New River Gorge, July 2001


Rock

Typ

e of

Mot

ion

Fall

Topple

Planar Slide

RotationalSlide

Flow

Avalanche





Rock Flow Debris Flow Earth FlowRock Avalanche

Debris Avalanche

Earth Avalanche

Landslides

Flow

Avalanche

Las Colinas Debris Slide-Flow,

Santa Tecla,El Salvador, 13 Jan 2001 Earthquake

Source: Reuters, viasearch.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 1985Debris Flow Track,

Twin Run, Pendleton Co., WV

Superelevation of Debris Flow, Twin Run

?

?

July 2001, Kanawha Valley, Glenn Ferris, WVIf you pictures or video, see Dr. Kite

Kanawha City Debris Flow: 3 Dead 1973

Stopped Here 20 Feb 2003: Mt. St. Helens Lahar, 1982

Lahar(= Debris Flow &Debris Avalanche)Hazard in the Seattle Area

This Image: http://vulcan.wr.usgs.gov/Imgs/Jpg/Rainier/Outreach/screen_poster_lahar_haz.jpg

Mount Rainier, WA

Seattle

Wet-slab avalanche, Quandary Peak, ColoradoColorado 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. Oktober2007 - 60000 Kubikmeter Gestein brechen am Einserkofel in Sexten Hochpustertal ab

http://www.youtube.com/watch?v=3jViIuA8xyI&NR=1

Mt. Huascaran, Peru, 1970

17,000 dead>300 km/h

How Fast?

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


Rock

Type

of M

otio

n

Fall

Topple

Planar Slide

RotationalSlide

Flow

Avalanche






Rock Avalanche

Debris Avalanche

Earth Avalanche

Landslides

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

u.s. landslide risk

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