2. There is a difference between tsunamis and tidal
waves, a tsunami is actually waves that come one
after the other and travel at a speed that is from 500
to 600 miles per hour in the open sea. Tsunamis are
not so easy to detect in the ocean and ships
because the wavelengths can be hundred miles
long with amplitude of just few feet. This makes the
undetectable by land. As these waves come close
to the sea coast, the speed reduces and the
amplitude rises. Though waves are known to rise as
100 feet, even 10 to 20 feet high is enough to cause
severe destruction and great cause of life.
3. FLOODS GENERALLY OCCUR WHEN THERE IS VERY HEAVY
RAINFALL . MOST COMMONLY ,FLOODS ARE CAUSED WHEN
A RIVER OVERFLOWS ITS BANKS AND THE WATER SPREADS TO
THE SURROUNDING AREAS.
FLOODS ARE ALSO CAUSED BY THE :-
COLLASPE OF A DAM BUILT ACROSS A RIVER .
BLOCKING OF RIVER CHANNELS BY LANDSLIDES .
CYCLONES AND TSUNAMI IN COSTAL AREAS.
WE CAN PREPARE FOR FLOODS IN THE FOLLOWING WAYS.:-
LISTEN TO THE RADIO OR WATCH TELEVISION FOR WARNING
AND ADVICE.
KEEP STOCKS OF FOOD AND FRESH WATER.
KEEP A RADIO ,TORCH AND MATCHBOXES AND CANDLES.
4. DROUGHTS
Some areas receive very little rainfall .
This causes an extreme shortage of water for
agriculture and domestic use .
We can prevent droughts by :-
Growing more tree
Developing rainwater harvesting system
Growing drought –resistant crops such as
maize , millets and sorghum.
5. EARTH QUAKES
SOMETIMES ,THERE ARE SUDDEN MOVEMENTS UNDER THE
SURFACE OF EARTH .THESE CAUSE STRONG VIBRATION
ON THE SURFACE OF EARTH.THIS IS KNOWN AS
EARTHQUAKE. IT CAUSE LOT OF DAMAGE TO LIFE AND
PROPERTY.
WE CAN TAKE THE FLOWING PRECAUTIONS DURING AN
EARTH QUAKE:-
GET OUT OF CARS AND BUSES IF YOU FEEL AN EARTH
QUAKE.
STAY AWAY FROM TREES , SIGNBOARDS , POLES AND
ELECTRIC WIRES.
6. Tornadoes are
characterized by violent
winds that swirl in a counter
clockwise direction north of
the equator and clockwise
south of the equator. Most
people recognize them as
a towering black funnel
extending downward from
the base of a large
cumulonimbus cloud. It
rotates at speeds up to
three hundred miles per
hour (480 kpm) or in some
rare cases, even faster. In
the center of the tornado,
the air pressure is very low in
comparison to surrounding
air pressure.
7. 1. . TICK THE CORRECT ANSWER.
A. GREAT LOSS OF LIFE AND PROPERTY CAUSED BY
a)NATURAL THINGS b)BLOCKING OF RIVER
c)NATURALDISASTER d)DISEASES
B. DURING AN EARTH QUAKE ,THE MAXIMUM
DAMAGE IS CAUSED NEAR THE
a) EPICENTRE c)SCHOOLBUILDING
b) FOCUS d)TREMOUR
8. C. THE FORCE OF AN EARTHQUAKE IS
MEASURED ON A
a) SEISMOGRAPH c) EPICENTRE
b) RICHTER SCALE d) SEISMOLOGY
D. WHICH VOLCANOES ARE THOSE THAT HAVE
STOPPED ERUPTING ?
a) DORMANT VOLCANOES
b) EXTINCT VOLCANOES
c) ACTIVE VOLCANOES
9. E .) WHAT IS THE COMMON NAME FOR A
TSUNAMI ?
a) FOCUS c) TIDAL WAVE
b) EPICENTRE d) EARTHQUAKES
