What is an Earthquake?

An earthquake is the intense shaking of Earth's surface caused by a sudden release of energy in the lithosphere. This release creates seismic waves that travel through the ground, causing the vibrations and damage we experience.

Causes of Earthquakes

• Tectonic Movements: The shifting and grinding of tectonic plates that make up the Earth's crust (the most common cause).
• Volcanic Activity: Fractures or movements in the Earth's crust during volcanic eruptions.
• Human-Induced Factors: Large reservoirs (dams), mining activities, or underground explosions.

[Image of different types of plate boundaries: convergent, divergent, and transform]

Measuring Earthquakes

Earthquakes are evaluated based on two scientific criteria:

• Magnitude: Measures the total energy released at the source. This is recorded using the Richter Scale.
• Intensity: Measures the observed effects and damage on the surface. This is recorded using the Modified Mercalli Scale.

Effects of Earthquakes

Seismic events can lead to secondary disasters such as:

1. Loss of life and structural damage to buildings and infrastructure.
2. Tsunamis: Giant waves caused by underwater earthquakes.
3. Landslides and soil liquefaction (where the ground loses its stability).