There is a difference between tsunamis and tidalwaves, a tsunami is actually waves that come oneafter the other and travel at a speed that is from 500to 600 miles per hour in the open sea. Tsunamis arenot so easy to detect in the ocean and shipsbecause the wavelengths can be hundred mileslong with amplitude of just few feet. This makes theundetectable by land. As these waves come closeto the sea coast, the speed reduces and theamplitude rises. Though waves are known to rise as100 feet, even 10 to 20 feet high is enough to causesevere destruction and great cause of life.
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.
DROUGHTSSome areas receive very little rainfall .This causes an extreme shortage of water foragriculture 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.
EARTH QUAKESSOMETIMES ,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.
Tornadoes arecharacterized by violentwinds that swirl in a counterclockwise direction north ofthe equator and clockwisesouth of the equator. Mostpeople recognize them asa towering black funnelextending downward fromthe base of a largecumulonimbus cloud. Itrotates at speeds up tothree hundred miles perhour (480 kpm) or in somerare cases, even faster. Inthe center of the tornado,the air pressure is very low incomparison to surroundingair pressure.
1. . TICK THE CORRECT ANSWER.A. GREAT LOSS OF LIFE AND PROPERTY CAUSED BY a)NATURAL THINGS b)BLOCKING OF RIVER c)NATURALDISASTER d)DISEASESB. DURING AN EARTH QUAKE ,THE MAXIMUM DAMAGE IS CAUSED NEAR THEa) EPICENTRE c)SCHOOLBUILDINGb) FOCUS d)TREMOUR
C. THE FORCE OF AN EARTHQUAKE IS MEASURED ON Aa) SEISMOGRAPH c) EPICENTREb) RICHTER SCALE d) SEISMOLOGYD. WHICH VOLCANOES ARE THOSE THAT HAVE STOPPED ERUPTING ?a) DORMANT VOLCANOESb) EXTINCT VOLCANOESc) ACTIVE VOLCANOES
E .) WHAT IS THE COMMON NAME FOR A TSUNAMI ? a) FOCUS c) TIDAL WAVE b) EPICENTRE d) EARTHQUAKES