ocean currents circa 1911

The following statements are false but are perceived to be true by many people. Scientific hypotheses and theories are subject to revision on the basis of observations, improvements in technology, and continued scrutiny. Inevitably certain "truths" are reconsidered. This is how honest science works. Brief explanations follow each of the FALSE statements and web site links are provided for reinforcement and/or substantiation. For the few items in which there is controversy or clear disagreement, the scientific view is presented.

T. Ansel Toney
Professor of Earth Sciences (retired)
©1990; last revision May, 2007

The ocean current off the east coast of Florida is the Gulf Stream.
Up-to-date physical oceanographers refer to it as the Florida Current. The Gulf Stream begins where the Antilles Current joins the Florida Current, sometimes as far north as Cape Hatteras, N.C. and ends off the Grand Banks of Newfoundland. The "catch" is that the Florida Current is a segment of the huge Gulf Stream Gyre.
Undertow is the most dangerous nearshore current.
Though "undertow" can be dangerous, outgoing rip currents are usually far more dangerous than undertow. Experts say that if you are caught in a rip you should swim parallel to the shore to quickly get out of the current.
Earthquakes cause tidal waves.
True tidal waves, called bores, are created by gravitational forces. "Seismic sea waves or tsunamis" are earthquake generated. Storm surges are caused by hurricanes.
The direction of movement of wind generated waves on water will give a good indication of the local wind direction.
Ocean waves can be generated by weather systems that are several hundred miles away. These waves or "swells" do not necessarily move in the same direction as the current local winds.
Spring tides take place once a year during the Spring season.
Spring tides occur when the moon is in conjunction (new moon) and about 14 days later when it is in opposition (full moon). The water "springs" away from the earth. This is when the high tides are the highest and the low tides are the lowest.
Sea water is many times denser than fresh water.
Sea water is denser than fresh water but not by much. Pure water at 4o Celsius has a density of 1.0000 grams/cm3 while sea water's density at the same temperature is 1.0278 grams/cm3. Sea water has a far greater salinity than fresh water; that might be what causes the confusion; its average salinity is 35,000 ppm. Drinking water is usually less than 500 ppm.
Sea conditions are calm under a hurricane's eye.
Though wind conditions can be "relatively" calm, sea conditions are usually violent and sometimes the wave heights are even greater than they would have been under strong winds.