Discovering Physical Geography 3rd Edition Arbogast Test Bank

The Geographic grid refers to the Earth’s coordinate system that can be used to identify any location on the Earth. This can be done by using it’s two components : Latitude and Longitude. Latitude refers to that part of the grid that determines those locations that lie North and South of the Equator whereas Longitude refers to that part of the grid that determines locations that lie East and West of the Prime Meridian.

Latitude is determined by measuring the angle of any point on the Earth’s surface located north or south of the Equator. It can be done by projecting two lines from the center of the Earth to its surface. One of these lines always extends from the center of Earth to its surface whereas the other line extends to the north or south from the center of Earth directly to the required location. The latitude of the location can then be calculated from the geometric arc between the two intersecting lines.

The arbitrary reference meridian for longitude is the Prime Meridian, which passes through Greenwich, England, at the Old Royal Observatory. Longitude is calculated by measuring the arc formed by two lines projected from the Earth’s center at the Equator. One line extends to the Prime Meridian, the other to the meridian of the required location. The angle of the arc formed by the two lines determines the longitude.