In physical geography, tsunamis (seismic sea waves) are mainly generated due to which of the following causes?

Introduction / Context:
Tsunamis are large ocean waves that can cause great destruction when they reach coastal areas. They have very long wavelengths and travel at high speeds across deep water. This question asks about the primary cause of tsunamis, which is a key concept in disaster management and physical geography.

Given Data / Assumptions:

• The phenomenon under discussion is the tsunami, also called a seismic sea wave.
• The options include ordinary wind generated waves, hurricanes, submarine earthquakes, Earth rotation and local tides.
• We must identify the main trigger responsible for most large tsunamis recorded in history.
• While there are other possible triggers, one is dominant in standard textbook explanations.

Concept / Approach:
Tsunamis are usually generated when a large volume of water in the ocean is displaced suddenly. The most common reason for this sudden displacement is a submarine earthquake that causes vertical movement of the sea floor. When the sea floor moves up or down abruptly, it pushes or pulls the overlying water column, creating waves that spread outward as a tsunami. Volcanic eruptions and landslides can also generate tsunamis but are less common globally than earthquakes.

Step-by-Step Solution:
Step 1: Understand that ordinary sea waves are mainly caused by wind blowing across the surface. These waves have relatively short wavelengths and do not qualify as tsunamis.Step 2: Hurricanes and tropical cyclones can create large storm surges, but these are different phenomena, driven by low pressure and strong winds rather than sudden vertical displacement of the sea floor.Step 3: Rotation of the Earth affects large scale currents and the Coriolis effect but does not directly produce sudden, giant waves like tsunamis.Step 4: Submarine earthquakes, especially those involving vertical fault movement in or near ocean basins, can rapidly lift or drop large sections of the sea floor.Step 5: This sudden change in sea floor position displaces water and creates the series of waves that we call a tsunami, so submarine earthquakes are the main cause.

Verification / Alternative check:
Historical events such as the Indian Ocean tsunami of 2004 and the Japan tsunami of 2011 were both triggered by strong undersea earthquakes. Reports and scientific analyses of these disasters consistently describe how fault movement on the ocean floor led to the tsunami waves. This pattern repeats across many documented tsunamis, supporting the claim that submarine earthquakes are the primary cause in most cases.

Why Other Options Are Wrong:
Wind generated sea waves are common and familiar but much smaller in wavelength and energy than tsunamis. Hurricanes produce storm surges, which are dangerous but are caused by wind and pressure rather than sudden sea floor motions. Rotation of the Earth influences currents and large scale circulation but does not generate sudden wall like waves. Local tides are regular and predictable changes in sea level due to lunar and solar gravity, not violent, sudden waves.

Common Pitfalls:
Some learners confuse storm surge and tsunami because both can flood coastal areas. They might therefore select hurricane or ordinary sea waves as the cause. Others may think of tides whenever they see large water movements near the coast. To avoid these mistakes, remember that tsunamis are associated with sudden vertical displacements of water, most often due to undersea earthquakes, while storm surges and tides result from different processes.

Final Answer:
Tsunamis are mainly originated due to submarine earthquakes.