Earthquake

An earthquake (also known as a tremor or temblor) is the result of a sudden release of energy in the Earth's crust that creates seismic waves

Earthquakes strike suddenly, without warning

Earthquakes can occur at any time of the year and at any time of the day or night

On a yearly basis, 70 to 75 powerful earthquakes occur throughout the world

An earthquake is a sudden, rapid shaking of the Earth caused by the movement of huge plates that form the surface of the Earth

Sometimes the plate movement is gradual

At other times, the plates are locked together, unable to release the accumulating energy

The plates break free causing the ground to shake

Most earthquakes occur at the boundaries where the plates meet

Some earthquakes occur in the middle of plates

An earthquake is just like throwing a stone in a pond of water

The point of disturbance below the surface of the Earth is called, FOCUS

The point directly above the FOCUS on the surface of the Earth is called, EPICENTRE

The vibrations are called SEISMIC WAVES

The study of earthquake waves is known as SEISMOLOGYThe experts who study the pattern of earthquakes are known as SEISMOLOGISTS

The machine which records the intensity of earthquake is known as SEISMOGRAPH

The recordings of the SEISMOGRAPH are converted into the actual intensity of the quake by using RICHTER SCALE

Richter scale was invented by Charles Richter in 1935Earthquakes measuring above 6 on the scale are very destructive

Earthquakes are experienced in the same regions where volcanoes are situated

Earthquake in INDIAHimalayan region is prone to earthquakes

Deccan plateau had earthquakes rarely and is considered safe from earthquakes

Some destructive earthquakes rocked India

Uttarkashi (Uttarkhand)1991Latur (Maharashrta)1993 Jabalpur (Madhya Pradesh)

1997Chamoli (Uttarkhand) 1999Bhuj (Gujarat)

2001Jammu & Kashmir2005Pak- Occupied Kashmir2007

Assignment for the day

Define earthquake.What is the reason for the shaking of the earth?

What is focus?What is epicentre?Define seismic waves? How do they travel?Explain the measurement of earthquakes.Why do earthquakes take place in the plate boundaries?

Kobe Earthquake, 17 jan 1995Japan is a country affected by

earthquakes.

It is located where the EURASIAN plate, PACIFIC plate and the PHILIPPINE plate meet.