Page 66 - ICSE GEOGRAPHY
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Aft er a fl ood—
• Return home only when the appropriate
authorities indicate it is safe.
• Stay out of any building if it is surrounded
by fl oodwater.
• Service the damaged septic tanks,
cesspools, pits and leaching systems as
soon as possible. Damaged sewage systems
are serious health hazards.
Children walking through Dadar railway station, when it Earthquakes
was fl ooded on 29th August, 2017
An earthquake is a sudden release of energy
Causes
in the earth’s crust due to the movement
Floods are caused by rains, strong
of tectonic plates. Earthquakes are natural
winds, cyclones, tsunamis, melting of snow
disasters that strike without an early warning.
or dam bursts. A fl ood can happen
Th e magnitude of an earthquake is measured
gradually or suddenly as a result of heavy
using the Richter Scale. Based on current
rains or a breach of the water storage and
instrumentation, it is estimated that around
control structures.
500,000 earthquakes occur each year around
Eff ects the world.
• A signifi cant number of human and
Causes
livestock deaths occur due to drowning
An earthquake is a result of the sudden break
and serious injuries.
or crack within the upper crust of the earth.
• Th ere is a high chance of the outbreak of
Th is could also cause the surface to break and
epidemics like diarrhoea, cholera, jaundice
could also lead to the vibration of the ground.
or viral infections in fl ood aff ected areas.
• Th ere is a shortage of safe drinking water Eff ects
as wells are submerged. • Earthquakes shake the ground. Th e severity
• Mud huts and buildings that are built on of the shaking depends on a range of factors
weak foundations collapse, and roads, that include the strength of the earthquake,
rails, dams, monuments and crops are the distance from the epicentre (origin
damaged. of the earthquake inside the Earth) and
• Utilities such as water supply, sewage, local geological conditions. Th e longer the
communication lines, power lines and ground shakes, the greater is the damage.
transportation networks are put at risk. • In mountainous regions, when the surface of
the slopes are weakened by the earthquakes,
Safety Measures
landslides and avalanches occur.
During a fl ood—
• When earthquakes take place under the
• Do not walk through moving water.
sea, seismic sea waves called tsunamis
• Do not drive into fl ooded areas.
are produced as a result. Th ese waves can
• Do not touch electrical equipment if you
travel at an enormous speed and cause
are wet or standing in water.
devastation along the coastal areas.
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