NATURAL DISASTERS



natural disaster caused by geographical factors, like earthquakes cyclones.

EARTHQUAKES







 earthquakes the shaking and vibration of the surface of the earth resulting from sudden movements inside The crust or as the result of volcanic activity is called an earthquake. the point of origin in the interior of the earth from where siesmic energy is released is called a siesmic focus. the point directly above it on the surface of the earth is called the epicenter. the shockwaves, called siesmic waves, which travel outwards from the Epicentre in a concentric circles, cause immense damage to places lying enroute. the closer to the epicenter a place is the greater is the damage it suffers.     

Measurement 

the magnitude of earthquakes is measured on the Richter scale on the Richter scale, earthquakes measuring less than 4 are called minor quakes; those measuring between 4 and 5.9 are called moderate, those  that are between  6 and 8 as strong, and those are more than 8 are called a great or Messive.

 effect of an earthquake 

If the intensity of earthquake is High, any of the effect mentioned below or a combination of them might occur--  

  • tidal waves
  • avalanches
  •  fire 
  • rivers changing courses and flooding
  •  death 
  • building collapse 
  • road and Bridge crumble 
  • breakage of gas lines
  • spills of hazardous chemicals 


precautions to be taken 



  • identify  a safe place at home, school in office-- under sturdy table or desk against an inside wall where nothing can fall on you.
  •  Practise three little vital steps of drop, cover and hold on. drop under I sturdy or table, Hold On, and protect your eyes by pressing your face against your arm. and if there is a no table or desk nearby, sit on the floor against an Interior wall away from Windows, bookcases, or tall furniture that could fall on you.
  •  if you are outside during an earthquake,  stay on open ground away from building, trees and electric poles which could fall on you.
  •  all buildings in earthquake- prone regions should be made as per the specification laid down by the Indian government. this should be Bolted  firmly to the ground.
  •  learn first aid and to operate a fire extinguisher.
  •  last last but not the least ,do not panic; stay calm.

    •  coping with the aftermath 

  • after the earthquake subsides, check for any injuries you might have received.
  • expect aftershocks. each time you feel One, drop, cover and hold on.
  •  Inspect your home for damage. get everyone out if your home is unsafe.
  •  look out for people who need your help -- the injured or the ones who are still trapped under the debris. 
  • administer first aid ,and then call for help .call either the police or the fire control personnel. 
  • look for an extinguish small fires . eliminate fire hazards. turn off the gas if you think it is leaking.
  •  listen to the radio for instructions.
  •  use the telephone only to report life threatning emergencies.

  •  offer  to help out in the relief camps set up to take care of the victims.

 tropical cyclones




 tropical cyclones are powerful,  spinning storms which form over warm tropical waters. they can reach winds speeds of over 120 km per hour. these storms are called a cyclones in the Indian ocean, hurricanes in the Atlantic ocean, and the Caribbean and the North-east Pacific Ocean, and typhoons  in the Western Pacific and the South Eastern Indian ocean.
 tropical cyclones move anti-clockwise in the Northern hemisphere and the clockwise in the southern hemisphere.

 effect of cyclones
  •  Torrential rains that can  cause flooding extremely strong winds that carry debris that can be lethal 
  • damaged building and property 
  • destroy crops
  • capsize boats at sea
  • uproot trees
  • cause deaths due to drowning 
  • destroy infrastructure, Rail and road services come to a standstill cyclone warning and come to stand still 

cyclone warning and coping with the cyclones

 the only effective way to copy with the cyclone is to forewarned.once forewarned, people should prepare themselves in a various ways.

  • have of portable radio and torchlight with a spare batteries. 
  •  check if the windows and doors securely bolted. identify a safe place at higher altitude to move to in  case things go out of control. 
  •  keep  emergency kits containing dry food items, water containers, emergency lighting, first aid kit, medicine and some clothes
  •  if the clone warning is severe, the Government makes provision to evacuate people from the path of the cyclone and move them to safer  places. keep important documents and valuables  ready to take with you.
  •  stand indoors still advise that the cyclone has passed.

 after the cyclone


  •  wait for complete clearance by the metro-logical department before venturing out. if you had to evacuate, do not go home until advised.
  •  use only recommended routes.
  •  beware of fallen Power-lines, damaged buildings, trees and flooded watercourses. tropical cyclones after India's East Coast every August and September. some times cyclonic conditions experienced even in  October and November along Tamil Nadu's coast.

 floods


  floods happen when a river has too much water in its channel. the water break through the river banks and spreads over the surrounding land.


causes of flood
  •  the main cause of flood is continuous downpour  of  heavy rain lasting at least three or four days.  this rain runs into the river where is a water level rise quickly giving rise  to floods.
  •  Hurricanes, cyclone and typhoons can cause of floods.
  •  earthquake of very high intensity on the ocean floor cause giant killer wave called tsunamis. the tsunami travel towards the shore at a great speed, flood  the flat coastal areas and  cause massive destruction of life and property.
  •  exceptionally high tides can also called floods in an region.  it creates high waves, which Rush up  the river that form the estuary.
  •  floods also occur when dams burst or when their gates are opened due to too much of water inflow.

 effect of floods
  •  road, railway line and buildings suffer damage.
  •  crop are damaged and trees uprooted.
  •  failure of electricity and gas supplies. water-borne diseases spread.
  •  it kills people and animals .
  • houses, vehicles and bridges get destroyed. ways to prevent and mitigate.

ways to prevent and mitigate


  •  we should insure your property. the insurance money will pay for repair and replacement of damaged items.
  •  we can put sand bags around our house and do to stop water from entering.
  •  if flood water enters the house, it can be pumped out.
  •  we must evacuate our houses, if there is  time. we should take essential  items such as clothes food and money and valuables with us. government should strengthen and increase the height  of the river banks.
  •  Dams should be built in Judiciously and used to  control floods. 

flood are an annual feature is a several part of India. during the monsoon months  many  of the river flood their Banks. Bihar and Orissa are the worst affected states.the government with the help of the army and navy launches rescue operations to move marooned people  to safer places.