hydrosphere & oceanography section 1 MCQ Questions & Answers Detailed Explanation

Answer: (d)

Answer: (c)

The Humboldt Current, also known as the Peru Current, is a cold, low-salinity ocean current that flows north-westward along the west coast of South America from the southern tip of Chile to northern Peru.

It is an eastern boundary current flowing in the direction of the equator and can extend 1,000 kilometres offshore. The Humboldt Current Large Marine Ecosystem (LME), named after the Prussian naturalist Alexander von Humboldt, is one of the major upwelling systems of the world, supporting an extraordinary abundance of marine life.

Upwelling occurs off Peru year-round but off Chile only during the spring and summer, because of the displacement of the subtropical centre of high pressure during the summer.

Answer: (d)

Tsunamis have a small amplitude (wave height) offshore, and a very long wavelength (often hundreds of kilometres long, whereas normal ocean waves have a wavelength of only 30 or 40 metres), which is why they generally pass unnoticed at sea, forming only a slight swell usually about 300 millimetres above the normal sea surface. They grow in height when they reach shallower water or the coast.

Answer: (a)

The correct sequence of terrigenous deposits from the coast to the deeper part of the sea is

Sand → Silt → Clay → Mud

Answer: (d)

Baltic Sea < Arctic Sea < Gulf of California < Red sea.

Answer: (c)