earthquakes ppt

EARTHQUAKES

Made by – Janie nakra

An earthquake is the sudden

shaking of the earth which lasts for

a very short time.

An earthquake is caused by violent

movements of rocks deep inside

the earth’s crust.

A major earthquake can cause

damage to life and property on a

large scale.

List of

earthquakes….

1) 26th Jan 2001 in bhuj district of Gujarat.

2) 8th Oct 2005 in Uri & tang Dhār towns

of north Kashmir.

1) 18th September 1737 in Kolkata in

west Bengal.

2) 5th March 2012 in new Delhi.

Structure of earth..

Earthquakes can cause

immense damage to houses

,buildings,bridges,dams and

people,etc.a lot of people get

killed when they get buried

under the debris of collapsed

houses and other buildings

during an earthquake.

Earthquake can also cause

Damage…..

Three layers of earth…The inside of earth is made up of 3

main layers of earth known as:

1)Core: The innermost part of the

earth is known as core

2)Mantle: The central region of the

earth between the core and crust.

3)Crust: The outermost layer of earth

is called crust.

Why do they occur?

Earthquakes occur when the moving plates of the

earth’s crust :

1. Slide past one another

1. Collide with one another

What are

seismic zones?

The weak zones of earth’s

crust are called seismic zones

or fault zones. Most major

earthquakes occur in the well

defined seismic zones called

earthquake belts.

SeismographIt is an instrument which measures and records the

magnitude of an earthquake in terms of the

shockwaves it produces.

Seismograph is also known as seismometer.

Focus and Epicenter

The place of origin of an earthquake

or moonquake is called focus.

The part of the earth's surface that is

directly above the place where an

earthquake starts is called an

epicenter.

Richter scale

An open-ended logarithmic

scale for expressing the

magnitude of an earthquake.

Thanks