Marine current power the rotation of the earth. The sun acts as the primary driving force, causing winds and temperature differences. Because there are only small fluctuations in current speed and stream location with minimal changes in direction, ocean currents may be suitable locations for deploying energy extraction devices such as turbines. Other effects such as regional differences in temperature and salinity and the Coriolis effect due to the rotation of the earth are also major influences. The kinetic energy of marine currents can be converted in much the same way that a wind turbine extracts energy from the wind, using various types
Valley of the Four Winds Valley of the Four Winds Valley of the Four Winds is a 1980 board game published by Games Workshop. "Valley of the Four Winds" is a game where the forces of good must hold evil at bay while evil's objective is to take and hold the city of Farrondil; the game was based on a story which was originally published in "White Dwarf". David Ladyman reviewed "Valley of the Four Winds" in "The Space Gamer" No. 37. Ladyman commented that ""Valley of the Four Winds" suffers from being a British import" due to its higher price in the U.S., but