Earthquake Effects Analysis

This section analyzes the two statements provided regarding the effects of earthquakes.

Statement I: Ground displacement, demolition of buildings, flooding are effects of Earthquake

This statement is true. Major earthquakes cause significant shaking of the ground. This shaking can lead to:

• Ground displacement: The earth's surface can shift, crack, or move horizontally and vertically along fault lines.
• Demolition of buildings: The intense vibrations and ground shaking can severely damage or destroy buildings and other structures not built to withstand seismic activity.
• Flooding: Earthquakes can trigger secondary disasters like landslides, which can dam rivers, causing floods. They can also cause liquefaction of soil, leading to ground failure and potential flooding, or damage coastal areas leading to inundation. In coastal regions, earthquakes can also trigger tsunamis, which cause widespread flooding.

These are well-documented consequences of significant seismic events.

Statement II: Earthquake in ocean floor do not create Tsunamis as seismic waves

This statement is false. Earthquakes occurring on the ocean floor are a primary cause of Tsunamis. While all earthquakes generate seismic waves that travel through the Earth, a specific type of undersea earthquake can displace a large volume of water above it. Key factors include:

• Location: The earthquake must occur under the ocean.
• Type: It typically needs to be a powerful, shallow earthquake involving vertical displacement of the seafloor (a subduction zone event is common).
• Mechanism: The sudden vertical movement of the seafloor displaces the overlying water column, creating waves that radiate outwards. These waves, initially small in the deep ocean but travelling fast, grow in height dramatically as they approach shallower coastal waters, becoming destructive tsunamis.

Therefore, earthquakes on the ocean floor can and frequently do create tsunamis.

Conclusion

Based on the analysis, Statement I is true, and Statement II is false.