EARTHQUAKES AND

CYCLONES

EARTHQUAKES

EARTHQUAKES

• An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth, which can be violent enough to destroy major buildings and kill thousands of people. Earthquakes have destroyed whole cities. They result from the sudden release of energy in the Earth's crust that creates seismic waves.

FOCUS AND EPICENTER• Focus is the place under the

earth’s crust where the plates collide.• Epicenter is the place above

the focus on the earth’s crust.

FOCUS AND EPICENTER

SISMIC WAVES

• Seismic waves are waves of energy that travel through the Earth's layers, and are a result of an earthquake, explosion, or a volcano.

HOW IS EARTHQUAKE MEASURED?

• Earthquakes are measured using observations from seismometers. The moment magnitude is the most common scale on which earthquakes are reported. Smaller earthquakes are measured mostly on the local magnitude scale, also referred to as the Richter magnitude scale.

SISMOMETER

How does earthquake occur?

• There are many* plates known as tectonic plates floating above the magma. When these plates collide, the tremors occur.

*The Earth has 14 major tectonic plates and 38 minor tectonic plates

How earthquake occurs?

CYCLONES

CYCLONE• Cyclone is a system of winds

rotating inwards to an area of low pressure , with an Anticlockwise (northern hemisphere) or clockwise (southern hemisphere) circulation.

• As warm, moist air over the ocean rises up from the ocean surface, there is less air left near the surface, and this causes an area of lower air pressure below. The air around this region has higher air pressure, and so it rushes in to fill the low pressure area. 

HOW CYCLONE OCCURS?

THANK YOU

JASMEHAK KARN VIII-A R.N.12