Solutions-Class 8-Geography-Chapter-5-Ocean Currents-Maharashtra Board

(iii) North Atlantic

(iv) Somali current

(iii) Land breezes

(iv) Thick fog

(iv) Deep ocean currents

Correct.

Correct.

Incorrect.

Correct statement : Generally, surface ocean currents are formed in the equatorial region as well as polar region.

Correct.

Incorrect.

Correct statement : The movement of icebergs  dangerous for water transport.

Incorrect.

Correct statement : Water becomes warm near Brazil due to ocean currents. Similarly, it also becomes warm near African coast.

The amount of precipitation increases in the coastal region along with which the warm ocean currents flow. Similarly, the temperature increases in the coastal region along with which the warm ocean currents flow.

Icebergs are transported away from the polar areas by cold ocean currents.  These icebergs form along the sea routes and threaten the ships.

The extended parts of coastline acts as an obstacle for ocean currents. The extended parts of coastline alters the direction and velocity of ocean currents.

• Dense fog is found in the meeting point of warm and cold ocean currents. Algae, plankton, etc. fish food grow on a large scale in these areas.
• Fish come in these areas on a large scale and breed. Therefore, extensive fishing grounds are found in the areas where warm and cold ocean currents meet.

• The ability of ocean currents to move water affects the quantity of precipitation and temperature in the coastal regions through which they travel.
• The transportation capability of ocean currents results in the passage of warm water from the surface to the bottom and cold water from the bottom to the surface.

• Deep ocean currents leads to transfer of warm water to the bottom from the surface and cold water to the surface from the bottom.
• Deep ocean currents thus leads to redistribution of sea water.

Because the Humboldt current is a cold ocean current, it reduces precipitation and temperature along South America's western coast.

The Arctic and Southern Oceans do not have any counter-equatorial currents. These oceans are found close to the polar regions. As a result, the impacts of trade winds are reduced in these waters. As a result, no counter-equatorial currents are detected in these oceans.

Cold currents are absent in the northern part of the Indian Ocean. The northern part of Indian Ocean is included in the temperate zone. So cold currents are absent in the northern part of the Indian Ocean.

The cold and warm ocean currents meet in the following regions :

• North Atlantic Ocean (cold Labrador current and warm Gulf stream current)
• North Pacific Ocean (cold Oyashio current and warm Kurishio current)
• South Atlantic Ocean (cold Falkland current and warm Brazil current)
• South Pacific Ocean (cold South Polar current and warm East Australian current)
• Indian Ocean (cold South Polar current and Agulhas Current)

• The temperature of the ocean varies by location. Similarly, the density of water in different sections of the ocean is found to differ.
• The difference in temperature and density of seawater causes circulation and the formation of deep ocean currents. This is referred to as thermohaline circulation.
• Thus, the differences in temperature and density of water in different sections of the ocean are the causes of the creation of deep ocean currents.

Planetary winds is the reason behind the dynamics of the ocean currents.

Winds give clockwise direction to the ocean currents in the northern hemisphere and anti-clockwise direction to the ocean currents in the southern hemisphere.

• The Labrador cold current travels along Canada's eastern coast.
• The temperature of seawater along Canada's eastern coast drops due to the Labrador cold current.
• Because of the drop in temperature, the sea water along Canada's eastern shore begins to freeze.
• As a result, the ports on Canada's eastern coast to freeze in the winter.