Landslide is a very common natural disaster and usually heard from the news and from our science-related subjects in school. But, have we really thought about it seriously?
“A landslide is the movement of rock, debris or earth down a slope. They result from the failure of the materials which make up the hill slope and are driven by the force of gravity. Landslides are known also as landslips, slumps or slope failure.”
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There are 2 types of landslides:
When the surface of rupture is curved concavely upward and the slide movement is roughly rotational about an axis that is parallel to the ground surface and transverse across the slide that is rotational slide. Whereas, translational slide happens when the landslide mass moves along a roughly planar surface with the little rotation or backward tilting.
There are a lot of causes but here are the most damaging ones around the world.
Slope saturation of water can occur in the form of intense rainfall, snowmelt, changes in groundwater levels and water level changes along coastlines, earth dams, and the banks of lakes, reservoirs, canals and rivers. Seismic activity, the occurrence of earthquakes in steep landslide-prone area greatly increases the possibility for landslides to occur, due to ground shaking alone or shaking caused dilation of soil materials, which allows rapid infiltration of water. And, volcanic activity is one of the devastating types. Volcanic lava may melt snow at a rapid rate, causing a deluge of rock, soil, ash and water that accelerates rapidly on the steep slopes of volcanoes, devastating anything in its path.
Finally, learning about landslides will be effective by following some safety tips.
What To Do During a Landslide
- Stay alert and awake. Many debris-flow fatalities occur when people are sleeping. Listen to a battery-operated radio, or television for warnings of intense rainfall.
- If you’re in areas susceptible to landslides and debris flows, consider leaving if it is safe to do so. Driving during an intense storm is hazardous. If you remain at home, move to second story if possible.
- Listen to unusual sounds that might indicate moving debris. A trickle of flowing or falling mud or debris may precede larger landslides. Moving debris can flow quickly and sometimes without warning.
- If you’re near a stream or channel, be alert for any sudden increase or decrease in water flow and a change from clear to muddy water. Such changes may indicate landslide activity upstream.
- Be alert when driving. Bridges may wash out and culverts overtopped. Don’t cross flooding streams. Watch the road for collapsed pavement, mud, fallen rocks and other indications of possible debris flows.
- Be aware that strong shaking from earthquakes may intensify the effects of landslides.
Awareness, knowledge and preparedness are the keys to survive from these natural disasters. But, protecting and sustaining our environment are also the things we should do because these are the ways that can prevent these calamities to be disastrous.
Australian Government Geoscience Australia. (n.d). What is a Landslide. Retrieved January 12, 2017 from, http://www.ga.gov.au/scientific-topics/hazards/landslide/basics/what
Landslide Hazard Information. (2004). Retrieved January 6, 2017 from, http://geology.com/usgs/landslides/
USGS Science for A Changing World. (n.d.). Landslide Preparedness. Retrieved January 6, 2017 from, http://landslides.usgs.gov/learn/prepare.php