Science / Tides and Currents / Variation (Of Compass): Difference between true north as determined by the Earth's axis of rotation and magnetic north as determined by the Earth's magnetism. Variation is designated as east or positive when the magnetic needle is deflected to the east of true north and as west or negative when the deflection is to the west of true north. The variation changes with time. Also called magnetic declination.
Variation Noun Synonyms: change, changing, alteration, altering, variety, varying, modification, modifying, difference, differing, diversification, diversity, diversifying, modulation, modulating, conversion, converting, permutation, permuting
Science / Tides and Currents / Speed (Of Constituent): The rate of change in the phase of a constituent, usually expressed in degrees per hour. The speed is equal to 360° divided by the constituent period expressed in hours. MORE
Science / Tides and Currents / Speed (Of Current): The magnitude of velocity. Rate at which the current flows. Usually expressed in knots or centimeters per second. MORE