hydrosphere & oceanography section 3 MCQ Questions & Answers Detailed Explanation

Answer: (d)

A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake.

Earthquakes, volcanic eruptions and other underwater explosions (including detonations of underwater nuclear devices), landslides, glacier calvings, meteorite impacts and other disturbances above or below water all have the potential to generate a tsunami.

Tsunami waves do not resemble normal sea waves, because their wavelength is far longer. Rather than appearing as a breaking wave, a tsunami may instead initially resemble a rapidly rising tide, and for this reason, they are often referred to as tidal waves.

Answer: (b)

El Niño is a climate cycle in the Pacific Ocean that causes global changes of both temperatures and rainfall. It is characterized by unusually warm ocean temperatures in the Equatorial Pacific, as opposed to La Niña, which is characterized by unusually cold ocean temperatures in the Equatorial Pacific.

Answer: (c)

1. Gulf Stream – Warm current
2. West Wind Drift – A slow eastward movement of water over the zone of westerly winds
3. Peru current – Pacific Ocean
4. West Australian current – Indian Ocean

Answer: (b)

Lagoon is a shallow stretch of water which is partly or completely separated from the sea by a narrow strip of land. In the case of coral reef, it is a channel of sea water between the reef and the main land. Lagoons are common coastal features around many parts of the world.

Answer: (b)

The Kuroshio current is warm due to variations in water level in the northern region of the East China sea and neighbour ocean.

Answer: (c)