Q.19. How are volcano, earthquake and tsunami related to each other? Highlight all the possible causes for volcanic eruptions.

Volcanoes, earthquakes, and tsunamis are interconnected natural phenomena, often occurring in regions where tectonic activity is intense.

• Relationship between Volcanoes, Earthquakes, and Tsunamis:

• Earthquakes: Most earthquakes occur due to the movement of tectonic plates. When these plates collide, slide past each other, or separate, stress builds up along fault lines. When the stress is released suddenly, it causes an earthquake. Volcanoes are often found near tectonic plate boundaries, where earthquakes are common.
• Volcanoes: Volcanoes form when molten rock (magma) rises from the Earth’s mantle and accumulates in chambers beneath the surface. The pressure from this magma can create cracks in the Earth’s crust. When the pressure exceeds the strength of the rocks above, the magma erupts through vents, forming a volcano. Sometimes, volcanic eruptions can also trigger earthquakes.
• Tsunamis: Tsunamis are powerful ocean waves caused by disturbances in the sea floor. While most tsunamis result from underwater earthquakes, they can also be triggered by volcanic eruptions under or near the sea. When an undersea volcano erupts, it can displace water, creating massive waves that spread across the ocean surface.

• Causes of Volcanic Eruptions:

• Buoyancy of Magma: Magma is less dense than the surrounding rock. As it rises toward the surface, it seeks out cracks and weaknesses in the Earth’s crust. When the pressure from the magma exceeds the strength of the rocks above, it erupts through volcanic vents.
• Exsolved Gases: Magma contains dissolved gases (such as water vapor, carbon dioxide, and sulfur dioxide). As magma rises, the decreasing pressure allows these gases to exsolve (come out of solution). The sudden release of gas can cause explosive eruptions.
• Injection of New Magma: If a new batch of magma enters an already filled magma chamber, it can increase pressure. This can lead to the eruption of the existing magma in the chamber.

In summary, the dynamic interplay between tectonic forces, magma movement, and geological structures gives rise to volcanoes, earthquakes, and tsunamis. Understanding these processes is crucial for predicting and mitigating their impact on our planet.