The highest tides on Earth occur in the Minas Basin, the eastern extremity of the Bay of Fundy, where the average tide range is 12 meters and can reach 16 meters when the various factors affecting the tides are in phase (although the highest tides occur typically a day or two after the astronomical influences reach their peak). Although it is the gravitation of the Moon and Sun that raises the tides, the energy in the churning waters is extracted from the rotational energy of Earth spinning on its axis. Near Annapolis Royal, Nova Scotia, a tiny portion of this energy is being converted into commercial electrical energy in the only tidal power plant in the Western Hemisphere. The peak output of the Annapolis Basin generator is 20 megawatts, about 1% of Nova Scotia's electrical power capacity. --source: http://www.valleyweb.com/fundytides/
Tide going out (and coming back in) at the Government Wharf, Parrsboro, Nova Scotia --source/images: Nova Scotia Museum; see animation at: http://museum.gov.ns.ca/fossils/protect/tideanim.htm
Tides are periodic rises and falls of large bodies of water. Tides are caused by the gravitational interaction between the Earth and the Moon. The gravitational attraction of the moon causes the oceans to bulge out in the direction of the moon. Another bulge occurs on the opposite side, since the Earth is also being pulled toward the moon (and away from the water on the far side). Since the earth is rotating while this is happening, two tides occur each day. Isaac Newton (1642 -1727) was the first person to explain tides scientifically. His explanation of the tides (and many other phenomena) was published in 1686, in the second volume of the Principia.
Spring tides are especially strong tides (they do not have anything to do with the season Spring). They occur when the Earth, the Sun , and the Moon are in a line. The gravitational forces of the Moon and the Sun both contribute to the tides. Spring tides occur during the full moon and the new moon. Neap tides are especially weak tides. They occur when the gravitational forces of the Moon and the Sun are perpendicular to one another (with respect to the Earth). Neap tides occur during quarter moons.
Why are they called spring and neap tides? Neap means low - so that is an easy one. Spring tides can be confusing because they have nothing to do with the season. It is not exactly known where the word 'spring' comes from in this context but there are two possible origins. One possible source is a Scandinavian word meaning to 'leap up'. Another possibility is that it is related to the natural feature of a spring - which is a place where water wells up from the earth.
ItÕs one thing to live right on the edge of the sea when big waves are crashing ashore, (Big waves, by the way, are generally caused by storm winds blowing on the ocean surface far offshore.) but add to it an extremely elevated sea level, and now those waves are breaking much higher up (and further ashore). So if there is big surf predicted for your area, and the tide charts show spring tides, you might evacuate or get those sand bags ready
Changing tides means organisms that are attached to the substrate are alternatively covered by water during high tides and exposed to air during low tides.
