focus on landslides

8/8/2019 Focus on Landslides

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Landslides Landslides Landslides Landslides

By Ginny Ruadh (P7)



WHAT CAUSES LANDSLIDESWHAT CAUSES LANDSLIDESWHAT CAUSES LANDSLIDESWHAT CAUSES LANDSLIDES

Scientists have recently found out that air

tides are responsible for causing landslides.

Heavy rainfall is the most common trigger mechanism.



LANDSLIDES:LANDSLIDES:LANDSLIDES:LANDSLIDES:

HOW DO THEY MOVE ?HOW DO THEY MOVE ?HOW DO THEY MOVE ?HOW DO THEY MOVE ?

LandslidesLandslidesLandslidesLandslides move in different ways

MudflowsMudflowsMudflowsMudflows move very fast usually afterlots of rain,

CreepsCreepsCreepsCreeps move slowly,

Earth flowsEarth flowsEarth flowsEarth flows collapses and envelophouses suddenly and

RockslidesRockslidesRockslidesRockslides detach from a steep clifflike the one in the picture.

All landslides have one thing in common - they are unpredictable, can happen at any time and kill.



A CATASTROPHE ?A CATASTROPHE ?A CATASTROPHE ?A CATASTROPHE ?

• Could it happen, even where we live?

Some landslides in Scotland

• 9 Sept 2009 - Landslide closes A83 as storms lash Scotland.

• 19 Aug 2004 - 57 motorists rescued - landslide at Lochearnhead.

• 26 Oct 2006 - On the Struie road near Alness, after a storm.

• 17 Jan 2010 - Landslide in Dumfries closes road.

DID YOU KNOW…

There have already been fatal landslides

in Scotland in recent years.

Landslide threat hangs over many of Scotland's most important roads



THE FACTSTHE FACTSTHE FACTSTHE FACTS

• Landslides can occur on any slope given the right conditionsLandslides can occur on any slope given the right conditionsLandslides can occur on any slope given the right conditionsLandslides can occur on any slope given the right conditions(Long, heavy rains)(Long, heavy rains)(Long, heavy rains)(Long, heavy rains)

• Landslides vary in size. They can be a smallLandslides vary in size. They can be a smallLandslides vary in size. They can be a smallLandslides vary in size. They can be a small rockfallrockfallrockfallrockfall or cover kmor cover kmor cover kmor cover km’’’’ssssdown a slope.down a slope.down a slope.down a slope.

• Landslides are very quick. In Canada, one landslide caused aLandslides are very quick. In Canada, one landslide caused aLandslides are very quick. In Canada, one landslide caused aLandslides are very quick. In Canada, one landslide caused a

riverbank to move 680 meters in less than an hour.riverbank to move 680 meters in less than an hour.riverbank to move 680 meters in less than an hour.riverbank to move 680 meters in less than an hour.

• Approx. 8000 are killed in landslides each year, all over the woApprox. 8000 are killed in landslides each year, all over the woApprox. 8000 are killed in landslides each year, all over the woApprox. 8000 are killed in landslides each year, all over the world.rld.rld.rld.

• Landslides occur without public warning. If you live in a landslLandslides occur without public warning. If you live in a landslLandslides occur without public warning. If you live in a landslLandslides occur without public warning. If you live in a landslideideideide----prone area,prone area,prone area,prone area, be alert.be alert.be alert.be alert.

• If you suspect that a landslide is about to occur or sees changeIf you suspect that a landslide is about to occur or sees changeIf you suspect that a landslide is about to occur or sees changeIf you suspect that a landslide is about to occur or sees changes ins ins ins in

your hillside surroundings,your hillside surroundings,your hillside surroundings,your hillside surroundings, make an emergency report.make an emergency report.make an emergency report.make an emergency report.



SOME LANDSLIDESSOME LANDSLIDESSOME LANDSLIDESSOME LANDSLIDES



TERMINOLOGYTERMINOLOGYTERMINOLOGYTERMINOLOGY



SOME LANDSLIDESSOME LANDSLIDESSOME LANDSLIDESSOME LANDSLIDES



THE TRAGEDY OF THE VICTIMS & SURVIVORSTHE TRAGEDY OF THE VICTIMS & SURVIVORSTHE TRAGEDY OF THE VICTIMS & SURVIVORSTHE TRAGEDY OF THE VICTIMS & SURVIVORS



LANDSLIDE PHOTOSLANDSLIDE PHOTOSLANDSLIDE PHOTOSLANDSLIDE PHOTOS



THE HEROTHE HEROTHE HEROTHE HERO’’’’S (RESCUE WORKERS)S (RESCUE WORKERS)S (RESCUE WORKERS)S (RESCUE WORKERS)



I m a g e s - B r i t i s h G e o l o g i c a l S u r v

e y



DIFFERENT TYPES OF LANDSLIDESDIFFERENT TYPES OF LANDSLIDESDIFFERENT TYPES OF LANDSLIDESDIFFERENT TYPES OF LANDSLIDES

• Creep – Extraordinarily slow, barely noticeable movement of earth along a slope,

caused mainly by alternating wet and dry periods.

• Fall – Rock mass that suddenly detaches and falls from the top of a steep slope, it

is caused by freeze-thaw action or by gravity.

• Flow – Sudden flow of mud along a slope; it occurs when torrential rains swiftly

drench the soil.

• Slump – complex movement of materials on a slope incl. rotation

• Topple - end over end motion of rock down a slope

• Slide – movement parallel to planes of weakness/slope



SIGNS OF EARTH MOVEMENTSIGNS OF EARTH MOVEMENTSIGNS OF EARTH MOVEMENTSIGNS OF EARTH MOVEMENT

• Titled trees

• Displaced gutters

• Cracks in road

• Lumpy ground

• Rockfalls

ROAD

AHEADCLOSED



D IS A S T E

R



IN THE NEWS TODAYIN THE NEWS TODAYIN THE NEWS TODAYIN THE NEWS TODAY…………

Hundreds of homes buried in a Landslide in MexicoHundreds of homes buried in a Landslide in MexicoHundreds of homes buried in a Landslide in MexicoHundreds of homes buried in a Landslide in Mexico

---- 29 Sept 201029 Sept 201029 Sept 201029 Sept 2010

A rescue worker (Oaxaca) said that, “the mountain had collapsedand a lot of people were in their homes because of the hour."

The town affected is Santa Maria (Tlahuitoltepec) where about9000 people live. The Oaxaca state is very mountainous. That,together with heavy rains caused a landslide to fall down onsleeping homes in the early hours of Tuesday.

Early estimates are that 500 - 600 people may be dead, injured orburied but a national newspaper (Excelsior) predicts that thedeath toll could approx. 1000.



IN THE NEWS TODAY..IN THE NEWS TODAY..IN THE NEWS TODAY..IN THE NEWS TODAY..

Deadly Landslide Caught On Camera In ColombiaDeadly Landslide Caught On Camera In ColombiaDeadly Landslide Caught On Camera In ColombiaDeadly Landslide Caught On Camera In Colombia

Wednesday September 29, 2010

Witnesses could only watch on helplessly as 30 people were burieWitnesses could only watch on helplessly as 30 people were burieWitnesses could only watch on helplessly as 30 people were burieWitnesses could only watch on helplessly as 30 people were buried by ad by ad by ad by a

landslide in Colombia.landslide in Colombia.landslide in Colombia.landslide in Colombia.

A deadly landslide caught a group of bus passengers off guard between two

villages northwest of the capital Bogota.

Their fate was caught on video as they changed from one vehicle to another on

a mountain road.

Suddenly, tons of earth swept down the hillside - burying everything in its path.



DIAGRAMSDIAGRAMSDIAGRAMSDIAGRAMS



WHAT CAUSES LANDSLIDESWHAT CAUSES LANDSLIDESWHAT CAUSES LANDSLIDESWHAT CAUSES LANDSLIDES

Human causes:

• removal of vegetation.

• interference with natural drainage.

• leaking pipes such as water and sewer

reticulation.

• Alteration of slopes by building of roads,

railways, buildings.

• overloading slopes;

• mining and quarrying activities;

• vibrations from heavy traffic, blasting, etc

• Excavation or displacement of rocks.

Natural causes:

• height of water,

• pressure (by saturation of slope material)

from either extreme or long-lasting

rainfall / seepage,

• vibrations caused by earthquakes;

• undercutting of cliffs and banks by waves

or river erosion; and

• volcanic eruptions.

Here is a list of some of the causes of landslides.



ON THEON THEON THEON THE LIGHTERLIGHTERLIGHTERLIGHTER SIDE OF LIFESIDE OF LIFESIDE OF LIFESIDE OF LIFE



REFERENCESREFERENCESREFERENCESREFERENCES

1. http://www.ema.gov.au/www/ema/schools.nsf/Page/Get_The_FactsLandslides2. http://www.virginmedia.com/digital/features/uk-disasters-waiting-to-happen.php?ssid=2

3. http://www.timesonline.co.uk/tol/news/uk/scotland/article6826849.ece

4. http://commons.wikimedia.org/wiki/File:Mud_closeup.jpg

5. http://www.ga.gov.au/hazards/landslide/causes.jsp

6. http://www.crh.noaa.gov/gid/?n=icestormgallery

7. http://slopes.jkr.gov.my/Slopesafety/monitor.html

8. http://contemplativehiking.com/

9. http://bobmckerrow.blogspot.com/2009_10_01_archive.html10. http://slopes.jkr.gov.my/Slopesafety/learn.html

11. http://web.viu.ca/geoscape/landslide!.htm

12. http://feww.wordpress.com/tag/landslides/

13. http://www.dailyrecord.co.uk/news/scottish-news/2009/09/08/landslide-forces-drivers-to-make-55-mile-detour-from-rest-and-be-thankful-86908-21657916/

14. http://skywatch-media.com/2008_08_01_archive.html

15. http://naturalplane.blogspot.com/2010_03_28_archive.html

16. http://news.stv.tv/scotland/151002-floods-cause-chaos/17. http://www.soton.ac.uk/~imw/lymchar.htm

18. http://www.ossfoundation.us/projects/environment/global-warming/summary-docs/leading-edge/2010/aug-the-leading-edge

19. http://www.thesun.co.uk/sol/homepage/news/3071251/Huge-landslide-crushes-village.html

20. http://ayrshiregeog.blogspot.com/2007_11_01_archive.html

21. http://www.shahidulnews.com

22. http://www.reuters.com/article/idUSTRE68404Q20100906

23. http://www.emirates247.com/landslides-kill-dozens-in-guatemala-1.288055

24. http://www.cbsnews.com/stories/2010/04/07/world/main6370356.shtml25. http://www.topnews.in/air-tides-responsible-causing-landslides-2231418

26. http://visual.merriam-webster.com/earth/geology/landslides.php

27. http://listverse.com/2007/10/20/top-10-natural-disasters/

28. http://www.travelblog.org/Photos/56358

29. http://daveslandslideblog.blogspot.com/2008_11_01_archive.html

30. http://news.sky.com/skynews/Home/World-News/Colombia-Landslide-Dozens-Killed-When-Mudslide-Buries-Mountain-Highway-And-Homes/Article/201009415747522?lpos=World_News_Carousel_Region_3&lid=ARTICLE_15747522_Colombia_Landslide:_Dozens_Killed_

When_Mudslide_Buries_Mountain_Highway_And_Homes

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