Eastern Hemisphere

The Eastern Hemisphere is one of the two halves of the Earth. It is defined by specific lines of longitude. This hemisphere sits east of the prime meridian. It also sits west of the antimeridian.

The prime meridian passes through Greenwich in London, United Kingdom. The antimeridian crosses the Pacific Ocean. This area is often called the "Old World." It is also known as the "Oriental Hemisphere." In some cases, people use the term in a cultural or geopolitical sense. It includes the massive landmasses of Afro-Eurasia and Australia.

To understand how this hemisphere is defined, we must look at its boundaries. Unlike the equator, these boundaries are not natural features. The equator is an imaginary line that divides the Northern and Southern hemispheres. It is equidistant from the poles. However, the division between East and West is an arbitrary convention. This means it is a rule decided and published by people. The prime meridian is located at 0° longitude. The antimeridian is located at 180° longitude. These lines divide the eastern longitudes from the western longitudes.

This global system was established through a specific historical process. Before standard time was adopted, many countries used different prime meridians. Each country defined time by its own local noon. This made global coordination difficult. In 1884, leaders met at the International Meridian Conference. This meeting took place in Washington, D.C. During this conference, they adopted the standard time concepts of Sir Sandford Fleming. He was a Canadian railroad engineer. This decision created the unified system we use for navigation and physics today.

Geography does not always align perfectly with these lines. The hemispheres do not correspond exactly with continents. For example, parts of Western Europe and West Africa are in the Western Hemisphere. Some parts of Oceania and northeastern Russia are also in the West. This can separate parts of a continent from the "East" or "West" labels. Because of this, some people use different lines for non-scientific purposes. They might use the 20°W and 160°E meridians instead. These lines include the African and European mainlands but exclude parts of New Zealand and eastern Russia.

The Eastern Hemisphere contains much more land than the Western Hemisphere. This large landmass allows for a wide variety of habitats. The center of this hemisphere is located in the Indian Ocean. It sits at the intersection of the equator and the 90th meridian east. This point is 910 km west of Indonesia in the Ninety East Ridge. The nearest land to this center point is Simeulue Island.

Many sovereign states are split between the Eastern and Western hemispheres. The United Kingdom is one example because the prime meridian passes through it. Most of the country is in the Western Hemisphere. France is also split, with about one-third of the country in the West. This includes cities like Nantes and Bordeaux. Spain is mostly in the Western Hemisphere, including the capital, Madrid. Even the United States is split. While most of the country is east of the 180th meridian, the Aleutian Islands and Guam are in the West.

Some countries are uniquely positioned by these lines. The country of Kiribati is very special. It is the only country located in four hemispheres. This is because both the equator and the 180th meridian cross its territory. Other nations like Fiji and Tuvalu also sit near these major boundaries. The 180th meridian is also known as the International Date Line. Most countries near this line stay on just one side of it. However, the line curves around them, affecting how they track days.

The human impact on the Eastern Hemisphere is significant. Most of the world's population lives in this half of the planet. Specifically, 82% of all humans live in the Eastern Hemisphere. In contrast, only 18% of humans live in the Western Hemisphere. This distribution shows how much of the world's people are concentrated in Afro-Eurasia and Oceania.