LandslidesBy: Madeline Sette, Rachelle Kruzelak, Keaton Beckes, and Noah Orner

Definition ●Landslides are rock, earth, and/or debris flowing or sliding down slopes due to gravity.

Causes

●Heavy rains●Earthquakes●Volcano eruptions●Floods●Grading●Terrain Cutting●Droughts

Air

●Confined by falling rock debris, air may act as a cushion to reduce the friction between the sliding material and the underlying rock or ground.

Gravity

●Gravity provides the energy to displace the soil and bedrock, but other factors contribute to an increase in stress and decrease in strength. A stress tends to make part of a block material slide block material slide with respect to an adjoining part.

Vibrations

●Vibrations from blasting, heavy traffic and earthquakes also can contribute to shear stress and precipitate slides.

Speed

●Landslides travel at least over than 260 feet per second

Types●Rockfalls- large chunks of rock that tumble down a cliff or steep slopes●Lahars- ash from a volcano mixes with water, to form a thick river of mud●Earthflows- contain less water and flow more slowly; move shorter distances●Slope Failure- involve one block or a series of slump blocks●Slump- larges masses move downward and outward due to a gravity pull●Debris Slides- consist of moving masses of mud, soil, and rocks mixed with water

Hotspots

●Anywhere with steep slopes and weathering ●High mountain ranges, sheer cliffs, and steep sided river valleys ●Where volcanoes erupt and along coasts

Damage

●Causes a billion dollars of damage each year in the U.S. ●Average of twenty-five casualties a year in the U.S.

Effects

●Bury entire villages that are at the bottom of the mountain range

●Close roads

●Rapidly moving water and debris can cause trauma

●Broken gas, electric, water, and sewage lines can break

Effects

●Landslides also sweep up trees, cars, and buildings http://landslides.usgs.gov/ research/other/ centralamerica.php

Traffic Stops

●Landslides can cause a headache for many travelers on the road ●Landslides occur on hills near roads quite often causing bad traffic

Pictures

http://landslides.usgs.gov/research/other/centralamerica.php http://web.ndmc.gov.za /images/landslide1.jpg

Nevado Del Hulia

●It was on June 6, 1994 at 3:47 p.m.  ●Killed up to 2,000 people and only 271 bodies were found●1,700 were defined missing presumed dead, and buried under the mud ●20,000 people made homeless

Orosi, Costa Rica

●On August 31, 2005  ●7 people were killed ●More than 400 people made homeless ●23 homes completely destroyed

Panabaj, Guatamala

●On October 5, 2005, around four o'clock a.m. ●1,000 people were declared missing and presumed dead ●Fewer than 80 bodies recovered

Sarno, Italy

●On May, 1998.  ●Killed 118 people, and more than 1,500 people made homeless  

Peruvian Andes

●In 1977, a debris avalanche moved some 20 to 45 million cubic yards of earth materials at speeds of almost 100 miles per hour. This slide buried an entire city, killing most of its 19,000 inhabitants.

Safe Spots From Landslides

●Stay on hard bedrock that has not been moved lately or in the past

●Stay on relatively flat-lying areas far from slopes or river banks

●Stay at the top of ridges, away from the top of slopes 

If in Danger

  ●Call your fire or police departments ●Warn neighbors in danger ●Evacuate the premises immediately

Eyewitnesses to Landslides ●"It sounded like the mountain exploded, and the whole thing crumbled." -Dario Libatan    ●June 7, 1994, Jorge Garcia observed the landslide area and said, "only the roof of the school can be seen.“ – Jorge Garcia ●"It sounded like an earthquake. But it was not the earth moving. It was the air." - Febo Carillo   

●"When the... landslide hit the landslide hit the hillsides of Orosi, the town was able to stick together and recover from the natural disaster." – Amy Chan

Questions

1.What is a landslide?2.Name 3 causes to landslides?3.How fast can a landslide travel?4.What should you do if you are in danger of a landslide?5.What are the effects of landslides?6. What are landslide hotspots?7. What is the average number of casualties landslides cause each year in the U.S.?

Answers

1.Landslides are rock, earth, and/or debris flowing or sliding down slopes due to gravity.

2.Heavy rains, Earthquakes, Volcano eruptions, Floods, Grading, Terrain Cutting, Droughts 3.260 feet per second

Answers

4. Call your fire or police departments, Warn neighbors in danger, Evacuate the premises immediately

5. Bury entire villages that are at the bottom of the mountain range, Close roads, Rapidly moving water and debris can cause trauma, Broken gas, electric, water, and sewage lines can break

Answers

6. Anywhere with steep slopes and weathering, High mountain ranges, sheer cliffs, and steep sided river valleys, Where volcanoes erupt and along coasts

7. Average of25 average a year in the U.S.

Sources●Landslides. N.p., n.d. Web. 21 Jan. 2010. http://www.ussartf.org/landslides.htm

●Matthews, William H. “Landslides.” Encyclopedia Americana. Deluxe Library ed. 1990. Print.

●Spilsbury, Louise & Richard. Landslides and Avalanches in Action. New York, NY: Rosen Central, 2009. Print.

●Landslide (Mudslide) Saftey. Washington D.C.: Centers for Disease Control and Prevention, 2003. Print.

●http://landslides.usgs.gov/research/other/centralamerica.php

●http://web.ndmc.gov.za/images/landslide1.jpg

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