Static Quiz 27 June 2022 (Geography)

Solution: C
Justification:
Statement 1: An anti-cyclone — also known as a high pressure area — is a large atmospheric circulation system with the wind flowing clockwise around it in the Northern Hemisphere, and counterclockwise in the Southern Hemisphere.
Statement 2: The extents are generally large and the effects are also pronounced.
Statement 3: Anticyclones form from air masses cooling more than their surroundings, which causes the air to contract slightly making the air denser. Since dense air weighs more, the weight of the atmosphere overlying a location increases, causing increased surface air pressure. Winds are of moderate speed, and at the outer edges, cloudy and precipitation conditions exist. Cloudy conditions and precipitation exists at the periphery of anticyclones. Otherwise, such a high pressure region generally shows fine and clear weather.

Solution: A
Justification: Most earthquakes occur at the boundaries where the plates meet. In fact, the locations of earthquakes and the kinds of ruptures they produce help scientists define the plate boundaries. There are three types of plate boundaries: spreading zones, transform faults, and subduction zones. Transform Plate Boundaries are locations where two plates slide past one another. The fracture zone that forms a transform plate boundary is known as a transform fault. Most transform faults are found in the ocean basin and connect offsets in the mid-ocean ridges. A smaller number connect mid-ocean ridges and subduction zones. At spreading zones, molten rock rises, pushing two plates apart and adding new material at their edges. Earthquakes are located along the normal faults that form the sides of the rift or beneath the floor of the rift.

Solution: A
Justification: 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. However, most earthquakes are caused by the interaction of the plates not the movement of magma. Most earthquakes directly beneath a volcano are caused by the movement of magma. The magma exerts pressure on the rocks until it cracks the rock. Then the magma squirts into the crack and starts building pressure again. Every time the rock cracks it makes a small earthquake. These earthquakes are usually too weak to be felt but can be detected and recorded by sensitive instruments. Once the plumbing system of the volcano is open and magma is flowing through it, constant earthquake waves, called harmonic tremor, are recorded (but not felt).

Solution: D
Justification: Plate margins witness several plate collisions, sliding, transformation etc. that result into volcanism or earthquakes. Most of them are found in the Ring of Fire. Some earthquakes also occur within the plates but not as frequently as on the plate margins. The mechanism is explained by the plate tectonics theory

Solution: A
Justification: The Indian plate is moving at a speed of one centimetre per year towards the north and northeastern direction and this movement of plates is being constantly obstructed by the Eurasian plate from the north. As a result of this, both the plates are said to be locked with each other resulting in accumulation of energy at different points of time. Excessive accumulation of energy results in building up of stress, which ultimately leads to the breaking up of the lock and the sudden release of energy causes earthquakes along the Himalayan arch. Some of the most vulnerable states are Jammu and Kashmir, Himachal Pradesh, Uttaranchal, Sikkim, and the Darjeeling and subdivision of West Bengal and all the seven states of the northeast.