Natural disasterA natural disaster is a destruction caused by nature to the humanity.

Examples:

Earthquakes

Tsunamis

Cyclones

Landslides

Forest fires

Effects of Deforestation

Landslides became more frequent because of deforestation.

Deforestation has affected rain.

Less rain causes droughts and famine

Too much rain causes floods.

Metereologists, weather scientists, keep a careful watch on temperature, rainfall and humidity conditions all over the country.

Daily report given in the newspaper shows the maximum and minimum temperatures and the rainfall in many major cities of India.

Most newspapers carry INSAT-1B picture showing cloud patterns over India on the previous day

Weather reports in newspapers

INSAT-1B picture

Cyclones

They are powerful, spinning storms which form over warm tropical waters and reach wind speeds over 120 km/hr.

When it moves and crosses over land, it brings with it heavy rain and high velocity winds.

Effects of cyclones Torrential rain that can cause flooding

Extremely strong winds that carry debris that can be lethal

Damage buildings and property

Destroy crops

Capsize boats at sea

Deaths due to drowning

Infrastructure destroyed

Effects of cyclones

Droughts and famineLack of rain causes droughts.

Drought can cause crops to wither and dry up, it also affects the farming communities badly.

It can lead to a severe shortage of food called Famine.

Effects of Droughts

Hunger, thirst and famine

Wildfires

Diseases

Social conflicts

Migration and relocation

Effects of Droughts

Wildfire

Precautions to be takenConstruct reservoirs in advance to store water for emergency.

Check deforestation and plant trees.

Rainwater harvesting.

Urge people not to waste water or food.

Educate farmers periodically to avoid over cropping and overgrazing.

Layers of Earth

Earthquakes

The sudden shaking of ground is known as Earthquake.

It can be quite strong and can cause much damage.

To understand how an Earthquake is caused, we must first understand what lies inside the Earth

Causes for EarthquakeThe lithosphere or the crust literally floats on the mantle.

Earthquakes occur along the fault lines where the tectonic plates meet.

Convection currents in the magma makes the tectonic plates to move constantly.

Some plates slide past one another and form strains on the rocks.

An Earthquake results when the strains buildup and causes the rocks to break.

Tectonic Plates

Effects of Earthquakes Avalanches Tsunami

Death

Buildings collapse

Breaking of gas lines, roads and bridges

Flooding

Fire

Effects of Earthquakes

Detection of Earthquakes

Seismologists, measure the strength of an Earthquake by estimating the amount of energy released at the focus.

The focus is the point of origin of an Earthquake.

Seismic waves are detected, recorded and measured by instruments called seismographs.

Seismograph

Precautions to be taken

Identify a safe place at home, school and office – under a desk or against an inside wall.

Practice three vital steps of drop, cover and hold on.

If you are outside stay away from buildings, trees and electric poles.

Learn first aid and to operate a fire extinguisher.

Earthquake Fact on Himalayas

The Himalayas were formed before about 200 millions of years ago, when India collided with Asia for the first time. The collision made the two lands to rise and form Himalayas.