A vocabulary of landscape — a landscape of words
1467 entries
tide
The tide is the rise and fall of sea level caused by the gravitational pull of the moon and, to a lesser degree, the sun, combined with the earth’s rotation. Most coasts get two highs and two lows a day. The range varies enormously by place: a few inches in parts of the Mediterranean, over fifty feet in the Bay of Fundy, because the water sloshes in each ocean basin at a rate set by the shape of the basin.
Etymology
The word is Old English and originally meant a time or a season, not water at all. That older sense survives in Yuletide, eventide, noontide, and in the proverb about time and tide waiting for no man, which is not about the sea. The water meaning came later, from the tide being the most reliably timed event on a coast.
Notes
The tide is not a bulge of water traveling around the earth, which is the picture most people carry. It is a set of rotating wave systems in each ocean basin, turning around fixed points where the range is nearly zero, and the timing at any port depends on where it sits relative to those. That is why tide tables are computed port by port and why two places a few miles apart can differ by hours.