GPHY 102 Lecture Notes - Lecture 3: Spheroid, Subsolar Point, Mercator Projection

• School: Queen's University
• Department: Geography
• Course: GPHY 102
• Professor: Dr.Trezino

Document Summary

The shape of the earth (cid:149) earth is an oblate ellipsoid, Not a perfect sphere; bulges slightly at the equator (cid:149) equatorial axis 12,756 km (cid:149) polar axis 12,714 km (cid:149) differential (0. 3%) Direction of rotation (cid:149) earth rotates counterclockwise when viewed above the north pole. (cid:149) when viewed from space it rotates from west to east. Earth"s rotation (cid:149) earth rotates on its axis once every day (i. e. , once every 24 hours). (cid:149) important because: Provides the day as a measure of time. Axis of rotation provides reference for setting up geographic grid of latitude and longitude. It has an important effect on physical and life processes . Environmental effects of earth rotation: diurnal rhythm of energy air temperature, humidity, and air motion, coriolis effect. Winds and water deflected from expected direction (to right in north, left in south) Key to global winds and ocean currents: tides. Moon and sun exert gravitational pull on earth"s oceans.