Geographic coordination

vĩ ngang, kinh dọc

Latitude (vĩ độ) is a measurement of a location north or south of the Equator (xích đạo). In contrast, longitude (kinh độ) is a measurement of location east or west of the prime meridian at Greenwich (an imaginary north-south line that passes through both geographic poles and Greenwich, London, England, U.K.)

Lines of latitude (đường vĩ tuyến, also called parallels) are imaginary lines that circle Earth’s surface, running east and west parallel to the Equator (đường xích đạo). Lines of longitude (đường kinh tuyến, also called meridians) run between the geographic North Pole and the geographic South Pole and are used to measure distances from the prime meridian (kinh tuyến gốc).

The latitudes of the North Pole and South Pole are 90° north (N) and 90° south (S), respectively. Lines of latitude north of the Equator (the line that marks 0° latitude) are numbered from 1° to 89° N, and those south of the Equator are numbered from 1° to 89° S.
Lines of longitude east of the prime meridian (the line that marks 0° longitude) are numbered from 1° to 179° east (E). Lines of longitude west of the prime meridian are numbered from 1° to 179° west (W). The 180th meridian, or 180°—which can be drawn north-south from pole to pole across the middle of the Pacific Ocean—is the line of longitude exactly opposite the prime meridian.

The combination of meridians of longitude and parallels of latitude establishes a framework or grid that can be used to locate exact positions on a map or globe.

Routes

The Northwest Passage (NWP) is a long-sought sea route through the Arctic Ocean, connecting the Atlantic with the Pacific. It was first navigated in 1903-06