The Gulf Stream: A River In The Ocean

Franklin was a zealous observer as he traveled the Gulf Stream during his trans-Atlantic crossings, recording speed, direction and temperature data as he went. Although Franklin was one of the first to conduct a scientific study of the current, he certainly wasn't the last. Throughout the historical record, the amazing nature of the Gulf Stream has astounded those who have tried to understand it.

Maury and his 19th century contemporaries used their state-of-the-art equipment to measure water temperature, buoyancy and current speed information from around the world. He distributed special logs, each with 12 blank pages in the back, to Navy and merchant captains to record data from their travels. Maury and his staff poured over the notes from the crossings and generated the first edition of ''Wind and Current Charts'' in 1847.

Captains who were once reluctant to take part in Maury's study began to take notice when crossing times began to be dramatically reduced. One captain cut 35 days off a 110-day journey to Rio de Janeiro. Maury offered the charts for free to anyone who would send in data. Time was money for the sea captains. Maury was on his way.

His work was the foundation for much of the research over the next century. Oceanographers poured over reports of derelict ships and floating debris, a peril to navigation and a treasure-trove of information. As the location of the flotsam was plotted and the drifting debris was tracked, scientists gradually began to realize that currents formed oceans, not the other way around.

The Gulf Stream, they realized, was part of a grander system. Rather than a river in the ocean, they began to see the Gulf Stream as the western edge of the North Atlantic circulation. A powerful current rushing along the edge of a continent is rare on the planet but not unknown. Along the western edge of the Pacific Ocean and the coast of Japan, the Kuroshio Current rivals the Gulf Stream in force and magnitude. Similar to the Gulf Stream, the Kuroshio Current is part of a trans-Pacific system that spins in the same wheel-like North Atlantic, connecting the North Pacific, California and Equatorial currents.

Scientists have continued to study the Gulf Stream using increasingly sophisticated technology. They have found that the composition of the ocean bottom over which the current flows affects it more than previously recognized. As the Gulf Stream pushes north along the southeastern US, bits and pieces of the current break off into enormous whirling circles, or eddies, known as gyres. Scientists believe that gyres are created by the sloping seafloor that rises abruptly in a succession of submerged mountains known as the New England Sea Mounts. The undersea mountain tops shear off the bottom of the current as it rushes by, creating monstrous undersea whirlpools.

Most of the gyres fall away to the east, toward the center of the spinning wheel of circulation. There they can be surprisingly long-lived, some spinning for two or three years. Other track west where they can bathe the coast in a tropical bath of warm, crystal-clear water.

Although Maury's description of a ''river in the ocean'' may no longer be correct, at the time it was a milestone of understanding about the powerful forces that lie just over the eastern horizon of the Carolina coast. As technology and science continue to push the limits of our understanding of the forces that shape the Gulf Stream and the world around us, there is little doubt that the marvels of the ocean will continue to surprise and amaze those who take the time to plumb its watery secrets.

for a more detailed history of the gulfstream, also see The Gulf Stream, Stories and Tales of the Coast