Experts predict freak tides

Press, 24 December 1986, Page 6

Experts predict freak tides

NZPA-AP Washington A rare alignment of the Earth, sun and moon is expected to raise tides to near-record levels around the world between December 28 and January 4, a U.S. Government agency has warned. If coastal storms happen at the' same time, a danger of flooding is compounded, says the National Oceanic and Atmospheric Administration (N.O.XA-). The agency urged seaside residents, fishermen and boaters to check tide tables for the times of extreme rises and falls, and to be wary of the weather. The extreme tides result from a combination of six phenomena. Those are.— @ The solstice, which happened yesterday with the sun reaching its maximum southern point. © Tropic tides: On December 30 the moon will be at its maximum southern point during the monthly cycle, causing high and low tides known as tropic tides. © Perigee: Also on December 30, the moon will be closer to Earth than at any other time during its monthly cycle, increasing its gravitational pull. © New moon on December 31. The new moon occurs when the Earth, moon and sun form a line, increasing gravitational forces on Earth. © Perhelion: The Earth will be closer to the sun on January 3, than at any other time in the year, increasing the pull of the sun’s gravity. © Regression of the moon’s nodes: This is an 18.6-year cycle in which the orientation of the moon’s orbit varies slightly. The orientation with the greatest effect on Earth tides is happening at this time.