What Is a Meridian Circle?

The meridian, also known as the "meridian", is the auxiliary line hypothesized by humans for convenience of measurement, and is defined as a semicircle connecting the north and south poles on the surface of the globe and perpendicular to the latitude. All large circles on the earth that cut through the plane of the ground axis and the ground are called "warp loops". The semicircle divided by the poles by the coil is called "warp". The length of the meridian is about 20037km. Any two meridians are equal in length and intersect at the north and south poles. ^[1] Each meridian has its corresponding value, called longitude. Longitude indicates north-south direction.

The meridian refers to a large circle formed by the plane of the earth passing through the ground axis and the ground, which is called a meridian. The semicircle that the meridian circle is divided by the two poles is called "meridian", that is, "meridian". Longitude indicates the local north-south direction. The points on the same meridian have the same longitude. That is, a large circle formed by the plane passing through the ground axis and the ground is called a warp circle. All the meridian circles intersect at the north and south poles and are divided into two semicircles by the poles, which are called "meridian" or "meridian". Longitudes indicate north-south direction; intersect at right angles to all parallels. Each meridian on Earth is approximately equal in length. ^[1]

Warp World Important Area

1. Areas that pass by the equator: Gulf of Guinea, Congo Basin, East African Plateau, Mount Kilimanjaro, Malay Islands, Amazon Plains

2. Areas that the Tropic of Cancer passes through: North Africa, Arabian Peninsula, Indian Peninsula, Indochina Peninsula, South China, Taiwan Island, Hawaiian Islands, Mexican Plateau, Gulf of Mexico

3. Areas that the Tropic of Cancer passes through: South African Plateau, Australian Desert, Great Artesian Basin, Great Dividing Range, Central Andes, La Plata Plain, etc.

4. Areas crossed by the Arctic Circle: Europe, Northern Russia, Northern Canada, Alaska, USA

5. Antarctic Circle and the islands and peninsulas around the Antarctic continent ^[1]

Main warp

1.0 ° meridian: London, east of Paris, west of the Mediterranean, Sahara, Gulf of Guinea

2.30 ° meridian: East Murmansk, East Moscow, St. Petersburg, the junction of the Eastern Plains and the Pod Plains, the Black Sea, the Asia Minor Peninsula, the eastern Mediterranean, Cairo E, the Nile, the East African Plateau E, the west of the South African Plateau

3. 60 ° E meridian: Ural Mountains, Aral Sea, Iran Plateau, Arabian Peninsula W, Arabian Sea 4, 90 ° E meridian: Yenisei River, Altai Mountains, Junggar Basin, Tianshan, Tarim Basin, Qinghai-Tibet Plateau, Ganges Delta, Bay of Bengal

5, 120 ° E meridian: East of Lena River, Daxinganling, West of Beijing, East of Shanghai, Philippine Islands, Malay Islands, Western Australia

6, 150 ° E meridian: Eastern Siberia, Thousand Islands, Great Dividing Range, Canberra, Sydney

7, 180 ° meridian: international date change line, Bering Sea, Aleutian Islands, Tuvalu, Fiji, Western New Zealand

8. 30 ° W meridian: Central Atlantic

9.60 ° W meridian: Newfoundland, Caribbean, Guyana Plateau, Brazil Plateau, La Plata Plain, Antarctic Peninsula

10, 90 ° W meridian: Mississippi River, Gulf of Mexico, Central America

11, 120 ° W meridian: Rocky Mountain

12, 150 ° W meridian: Alaska, Hawaii, etc.

Geographical things in China

1. Tropic of Cancer: the hills of Guangdong and Guangxi, the Pearl River Delta of the Pearl River in the Yunnan-Guizhou Plateau; Shantou, Guangzhou

2. 30 ° N: Plains in the middle and lower reaches of the Yangtze River, the Sichuan Basin, the Yangtze River on the Qinghai-Tibet Plateau, the Lancang River, and the Nujiang-Shanghai-Ninghang Industrial Base; Hangzhou, Chongqing, and Lhasa

3. 40 ° N North China Plain, Loess Plateau, Yellow River, Tarim Basin, Beijing-Tianjin-Tangshan Industrial Base; Beijing, Datong, Dunhuang, etc. ^[1]