Distribution of land and water
Topic: Oceans: Hydrological Cycle, Relief of the Ocean Floor, Temperature and Salinity · NCERT: Class 6, Ch 2 "Oceans and Continents"
Meaning
About 71% of the Earth's surface is water and 29% is land. The two are not spread evenly. The Northern Hemisphere is called the "land hemisphere" because it holds about two-thirds of all land. The Southern Hemisphere is about 81% ocean. Because of this, northern oceans are warmer and their temperatures change more. Strong, steady westerly winds blow across the open southern seas. These winds are called the Roaring Forties.
Example
If you divide the globe into the half with the most land, its centre lies near western France. The half with the most water has its centre near New Zealand. Around 40°S, the open ocean south of Africa and Australia has few land masses to slow the winds, so the Roaring Forties blow there.