Page 110 - Genius Kidz Prudence Learning Sc-8
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Waves generated due to the disturbance in a STRUCTURE OF EARTH
hypocenter are called shock waves or seismic Earth consists of four layers :
waves.
(a) Inner core
Point on the earth surface i.e. vertically above
(b) Outer core
the hypocentre is called as epicentre.
(c) Mantle
Instrument that records the intensity of
seismic waves is called seismograph. (d) Crust
Core of the earth is composed of nickel and
Study of earthquakes is called seismology.
iron. Inner core is solid while the outer core is
Structure of earth
liquid. Silicate rocks that are rich in iron and
magnesium form the mantle. Mantle is viscous
in nature. Crust is ferromagnetic due to
ferromagnetic nature as silicates in them.
Mantle and crust form up the earth's surface.
In addition to the mantle and crust elements
surface also consists of large pieces (12 in
number) called tectonic plates.
Tectonic plates keep on moving over the
earth's mantle and they also slide upon one
another as a result of which plate boundaries
become weaker. Weaker boundaries of
Tectonic plates of earth
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