What is a tsunami?

A tsunami is a series of large, powerful ocean waves caused by underwater disturbances such as earthquakes, volcanic eruptions, or landslides. These waves can travel across vast distances in the ocean at very high speeds. When they approach shallow coastal areas, their speed decreases, and their height increases, often leading to destructive waves that can flood the land. Tsunamis can cause widespread damage to coastal cities, infrastructure, and result in loss of life. Early warning systems are crucial for saving lives and reducing the impact of tsunamis.

This question related to Chapter 2 Social Science Class 6th NCERT.
From the Chapter 2. Oceans and Continents.
Give answer according to your understanding.