Apogean Tide: A monthly tide of decreased range that occurs when the Moon is at apogee (farthest from Earth).
Diurnal Tide: A tide with one high water and one low water in a tidal day of approximately 24 hours.
Mean Lower Low Water: The arithmetic mean of the lesser of a daily pair of low waters, observed over a specific 19-year cycle called the National Tidal Datum Epoch.
Neap Tide: A tide of decreased range that occurs twice a month, when the Moon is in quadrature (during its first and last quarters, when the Sun and the Moon are at right angles to each other relative to Earth).
Perigean Tide: A monthly tide of increased range that occurs when the Moon is at perigee (closest to Earth).
Semidiurnal Tide: A tide with one high water and one low water every half day. East Coast tides, for example, are semi-
diurnal, with two highs and two lows during a tidal day of approximately 24 hours.
Spring Tide: A tide of increased range that occurs at times of syzygy each month. Named not for the season of spring but from the German springen (“to leap up”), a spring tide also brings a lower low water.
Syzygy: The nearly straight-line configuration that occurs twice a month, when the Sun and the Moon are in conjunction (on the same side of Earth, at the new Moon) and when they are in opposition (on opposite sides of Earth, at the full Moon). In both cases, the gravitational effects of the Sun and the Moon reinforce each other, and tidal range is increased.
Vanishing Tide: A mixed tide of considerable inequality in the two highs and two lows, so that the lower high (or higher low) may become indistinct or appear to vanish.
Answers to Maddening Mind-Manglers
from page 233
SLICK TRICK
1. ock or ash
2. int
3. ips
HOW’S THAT FOR HOSPITALIT Y? During that time, the eight of them assumed 40,320 positions ( 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1). The innkeeper entertained his guests for 40,320 days, or 110 years and
142 days ( 40,320 ÷ 365.25 days = 110. 39 years; 0.39 x 365.25 = 142. 44 days).
Y, SURE!
1. myrrh
2. nymph
3. syzygy
4. crypt
References:
Archives