Page 100 - Journeys Through Society-7
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Wow Fact Movement of Water
Waves
A jellyfish and a cucumber are each 95%
water. Waves are formed when energy is transferred from
one molecule of water to another, across the surface
of the ocean. The water molecules hardly move. It is
Water Cycle
the energy that actually gets transferred. As waves
The movement of water from the hydrosphere to the break across a shore or crash in violent storms, they
atmosphere, and then to the lithosphere and cause great turbulence in ocean water.
biosphere, and back to the hydrosphere is known as
the water cycle. The water cycle is one of nature's Tsunamis
most important processes. Water evaporates into the Tsunamis, are extremely dangerous and destructive
atmosphere, falls on Earth as rain or snow, and flows waves caused by earthquakes near or under the
back into the oceans to begin the cycle again. The ocean. Volcanic eruptions and submarine landslides
energy needed to keep the cycle moving smoothly also cause displacements in ocean floors, resulting in
comes from the Sun. tsunamis.
According to scientists, tsunamis are not “tidal waves”
which are caused by tides. Neither are they typical
ocean waves generated by wind and storms.
Generally, tsunamis do not ‘break’ like the curling,
wind-generated waves, popular with surfers.
Technically, tsunamis comprise multiple waves with
extremely powerful currents rushing towards the
shore. On approaching the shore, they move like a
very fast moving tide, extending much farther inland
Water cycle than normal waves.
Rain is the primary source of freshwater. It feeds
rivers, lakes and groundwater resources, which are
the secondary sources of water. The journey of water
starts as it evaporates from the saline oceans and seas
and enters the atmosphere as vapour to form clouds.
Clouds then cool, condense and finally precipitate in
the form of rain, hail or snow over the land. This
natural process brings to us the fresh or sweet water
that brings life to the Earth.
Destruction caused by a Tsunami
Ocean Water
When a tsunami-causing disturbance occurs close to
Oceans make up 71 per cent of the Earth's surface and the coastline, the resulting tsunami can reach coastal
are connected to each other. Oceanic waters are communities within minutes.
interspersed with many smaller marine bodies like
seas, gulfs, and bays. Look up a world map and locate Ocean Currents
various smaller marine bodies that lie between oceans. Ocean currents are like large rivers flowing within the
Wow Fact ocean from one place to another. They move in a
clockwise direction in the northern hemisphere and in
On Venus and other moons and planets, rain an anti-clockwise direction in the southern
is made of sulfuric acid and methane.
hemisphere. This is because the Earth is spherical in
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