Daily Current Affairs Quiz: August 05, 2025

Statement 1 is incorrect: The Southern Ocean is the fourth largest of the world’s five principal oceans (Pacific, Atlantic, Indian, Southern, Arctic).

Statement 2 is correct: In 2000, the International Hydrographic Organization (IHO) established the Southern Ocean as the body of water extending from the coast of Antarctica to 60°S latitude.

Statement 3 is incorrect: While the Antarctic Convergence significantly influences the Southern Ocean’s characteristics, the ocean’s boundaries are defined by latitude (60°S), not the convergence zone. The Convergence marks where cold, northward-flowing Antarctic waters meet and sink below the relatively warmer subantarctic waters. It doesn’t perfectly align with the 60°S parallel.

Statement 4 is incorrect: The Antarctic Circle lies at approximately 66.5°S latitude. While a significant portion of the Southern Ocean lies south of the Antarctic Circle, the ocean’s northern boundary is officially defined as 60°S latitude. Therefore, not all waters south of the Antarctic Circle belong to the Southern Ocean; a portion between 60°S and 66.5°S lies within the Southern Ocean, but north of the Circle.

Coral reefs typically begin as fringing reefs, growing directly from the shoreline of an island or landmass. As the island subsides or sea level rises, a lagoon forms between the reef and the shoreline, creating a barrier reef. If the island completely subsides beneath the sea surface, leaving the ring-shaped reef surrounding a central lagoon, an atoll is formed.

Statement 1 is correct: The Gulf Stream is a warm and swift Atlantic Ocean current that originates in the Gulf of Mexico.

Statement 2 is correct: It significantly influences the climate of the east coast of North America and the west coast of Europe.

Statement 3 is correct: The temperature difference between the Atlantic Ocean and the Gulf of Mexico contributes to its formation.

Statement 4 is correct: It plays a crucial role in the weather patterns of the North Atlantic, especially contributing to milder winters in Western Europe.

Statement 1 is correct: Harry Hess proposed the theory of seafloor spreading in 1960.

Statement 2 is correct: Seafloor spreading occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.

Statement 3 is correct: Seafloor spreading is a key process that helps explain the mechanism of continental drift in the theory of plate tectonics.

Statement 4 is correct: The discovery of symmetric magnetic stripes on the ocean floor, which record reversals of the Earth’s magnetic field, serves as strong evidence for seafloor spreading.

Statement 1 is incorrect: Coastal regions often have lower salinity due to freshwater influx from rivers and precipitation.

Statement 2 is correct: Freshwater from rivers decreases the salinity in nearby ocean areas, such as in estuaries.

Statement 3 is correct: The Mediterranean Sea has higher salinity than the Atlantic due to higher evaporation and limited freshwater inflow.