[Mission 2022] QUIZ – 2020: INSIGHTS STATIC QUIZ , 22 October 2021 – Geography

Solution: d)

Olympus Mons is a shield volcano located in Mars’ western hemisphere. It is the largest volcano in the solar system.

Some, but not all, earthquakes are related to volcanoes.

Solution: d)

These volcanoes are characterized by eruptions of cooler and more viscous lavas than basalt. These volcanoes often result in explosive eruptions. Along with lava, large quantities of pyroclastic material and ashes find their way to the ground. This material accumulates in the vicinity of the vent openings leading to formation of layers, and this makes the mounts appear as composite volcanoes.

Solution: d)

Atlantic coasts have very few volcanoes and that too dormant ones.

A hot spot is a region deep within the Earth’s mantle from which heat rises through the process of convection. This heat facilitates the melting of rock. The melted rock, known as magma, often pushes through cracks in the crust to form volcanoes.

Hot spot volcanism is unique because it does not occur at the boundaries of Earth’s tectonic plates. Instead it occurs at abnormally hot centers known as mantle plumes.

Hot spring, also called thermal spring, spring with water at temperatures substantially higher than the air temperature of the surrounding region. Most hot-springs discharge groundwater that is heated by shallow intrusions of magma (molten rock) in volcanic areas. Some thermal springs, however, are not related to volcanic activity. In such cases, the water is heated by convective circulation: groundwater percolating downward reaches depths of a kilometre or more where the temperature of rocks is high because of the normal temperature gradient of the Earth’s crust—about 30 °C per kilometre in the first 10 km.

Solution: a)

Some, but not all, earthquakes are related to volcanoes. For example, most earthquakes are along the edges of tectonic plates. This is where most volcanoes are too.

Plate margins witness several plate collisions, sliding, transformation etc that result into volcanism or earthquakes.

Solution: a)

Earthquake waves are basically of two types — body waves and surface waves. Body waves are generated due to the release of energy at the focus and move in all directions travelling through the body of the earth.

There are two types of body waves. They are called P and S-waves. P-waves move faster and are the first to arrive at the surface.

The P-waves are similar to sound waves. They travel through gaseous, liquid and solid materials. S-waves arrive at the surface with some time lag. These are called secondary waves. An important fact about S-waves is that they can travel only through solid materials.

The velocity of waves changes as they travel through materials with different densities. The denser the material, the higher is the velocity. Their direction also changes as they reflect or refract when coming across materials with different densities.