Interior of earth

1. Name-Rupsha Sarma
Roll no.-24
Class and Section-7f

2. The structure of the earth is divided into four
major components: the crust, the mantle,
the outer core, and the inner core. Each layer has a
unique chemical composition, physical state, and
can impact life on Earth's surface.

3. In geology, a crust is the outermost layer of a
planet. The crust of the Earth is composed of a
great variety of igneous, metamorphic, and
sedimentary rocks. The crust is underlain by the
mantle. The upper part of the mantle is composed
mostly of peridotite, a rock denser than rocks
common in the overlying crust.

4. The mantle is the mostly-solid bulk
of Earth's interior. The mantle lies
between Earth's dense, super-heated core and its
thin outer layer, the crust. The mantle is about
2,900 kilometres (1,802 miles) thick, and makes
up a whopping 84% of Earth's total volume. It is
composed mostly of silicate rocks rich in
magnesium and iron. Intense heat causes the
rocks to rise.

5. Earth's outer core is a layer of liquid rock that is
about 2,400 km (1,500 mi) thick and composed of
mostly iron and nickel that lies
above Earth's solid inner core and below its
neither solid and liquid mantle. ... Unlike
the inner (or solid) core, the outer core is liquid.

6. The inner core is the very centre of
the Earth, and the hottest part of the
planet. It is a mainly a solid ball with
a radius of about 1,220 km (760 mi),
according to seismological
studies.[1][2] It is believed to consist
mostly of an iron–nickel alloy and to
be about the same temperature as the
surface of the Sun: about
5700 K (5400 °C).[3]
The inner core was discovered by Inga
Lehmann in 1929, using seismology.
Lehman was studying a large New
Zealand earthquake.
An earthquake makes vibrations
which move through the inside of the
Earth. The vibrations Lehmann
studied seemed to be moving across
something solid in the centre of the
planet. She called this the inner core.
She wrote about it for many years, but
it was not proved to exist until 1970.