Georgia Tides - Some of the Highest on the Atlantic Coast
Typical of tidal patterns along the southeastern coast, Georgia has two high tides and two low tides each day. The range of Georgia’s tides, however, is not typical. While Cape Hatteras, North Carolina, has 2-3 foot tides and Miami, Florida, has 1-2 foot tides, the Georgia Coast has 6-9 foot tides. The reason is that it is the approximate center of the curved coastline known as the Georgia Bight, which extends from Cape Fear, North Carolina, to Cape Canaveral, Florida. The tide as it approaches the Atlantic Coast is a very long wave with duration of 12 hours and 25 minutes, and it is approximately 2-to-3 feet high. The concave shape of the Georgia Bight causes the tidal wave to pile up towards the center of the bight. Therefore, when the tide reaches the Georgia coast, it is higher than in the Carolinas or in Florida. The high tidal range and the extremely gradual slope of the continental shelf allow tidal water to penetrate deeply into the coast. Tidal movement can be detected as much as 40 miles up some Georgia coastal rivers.
Extreme “spring” tides, which produce the highest high tides and the lowest low tides, occur at new and full moons. The smallest “neap” tides, which produce the lowest high tides and the highest low tides, occur at the first and second quarter phases of the moon. The extent of storm-caused beach erosion is directly related to this lunar cycle. A storm occurring at a “spring high” in this region can do as much damage as a hurricane on a coast where there is small tidal range.