Due North: The St. John's River is One of Many
Dr. M. Kamiar is a Professor Emeritus of geography at Florida State College at Jacksonville and for decades he found himself continually correcting his students when they parroted the phrase, "the St. Johns River and the Nile River are the only two rivers in the world that flow north." In this editorial he explains that there are hundreds of rivers that flow north and; in fact, the St. Johns River flows south as well.
Published April 27, 2013 in Opinion - MetroJacksonville.com
There is a common belief in northeast Florida, especially in the city of Jacksonville, that there are only two rivers in the world that flow north: One is the St. Johns and the other one is the Nile. For the past 15 years, I have been reminded of this so-called geographical fact too many times -- every time, in fact, that the geography classes I teach begin a new term. A few of my students will no doubt mention it to me every term. But I correct them, and I’d like to use this article to correct others. Contrary to popular belief, more rivers run north than any other direction!
Direction of rivers has less to do with magnetic forces than gravity, topography and geomorphology. As the source of a river is higher than the mouth, it will follow a path of least resistance along its course. In my assessment of the world’s rivers, excluding small ones and those with no clear pattern, I identified more than 245 rivers that flow north.
In recent years, the claim that the St. Johns is one of just two rivers to flow north has been replaced by the claim that it is “one of the few” to do so. Online sources mention several rivers that lay claim to this distinction, including the Fox (in eastern and central Wisconsin), the Genesee River (in New York), the New River (in Ashe County, North Carolina), the Red River (in Minnesota) and the St. Johns. If we add the Nile to the above list, we have a total of five rivers. Obviously the claim that there are “only two” north-flowing rivers is incorrect. But the “few” statement is misleading, too.
A river is a natural waterway that carries runoff fresh water over a landscape from higher to lower altitudes. The direction of the flow of each river in the world is determined by the topography between the headwater and the mouth. Rivers, like all other objects, flow downhill. They all take the paths of least resistance. This path thus could take any direction -- east, west, north, south, and many others in between. Rivers that meander may flow in many directions. Where there are low gradients and gentle slopes, some rivers may flow almost in full circles. Compass directions, then, do not influence flow. Unfortunately, some people associate “north” with “uphill” and “south” with “downhill.” To them, north is always higher than south. This may be the original myth leading to false conclusions about rivers. But in many parts of our planet, north is actually lower than south.
Over geological time, many rivers have changed course. Before the break-up of the super continent of Pangaea and before the beginning of the mountain-building process that happened nearly 250 million years ago on the west coasts of North and South America, both the Amazon and Mississippi rivers emptied into the Pacific rather than the Atlantic Ocean. Back then, the continent of Africa did not have its own coastlines; thus many rivers, including the Nile, had interior deltas on large, interior lakes. Post-drift African rivers built new deltas on the coast, with sudden changes in the direction of their flow, including descending from the high plateau. Most of them have rapids and waterfalls, in fact, which is why about half of the world’s potential hydroelectric-power is found in Africa.
The orientation of the St. Johns River is not an exception to natural laws. It is rather an illustration of nature’s efficiency. More than 100,000 years ago, most of the land that now is occupied by the St. Johns River basin was an arm of the Atlantic Ocean. The river itself was a part of an extended system of bays, inlets, lagoons, lakes, and tributaries. The separation started during the last ice age, about 15,000-20,000 years ago, when Florida was almost 2.5 times larger than today.
The St. Johns River has a very gentle slope. The elevation near its origin in the marshes of central Florida is about 30 feet. St. Johns River’s gradient is one inch per mile. This drop over the river’s 310-mile course makes it one of the slowest moving rivers in the world. This, coupled with Florida’s Karst system of sinkholes and other geomorphological factors, has made a river that has many lakes along its course.
The St. Johns is a non-alluvial river. It does not erode its banks and channels, due to its gentle slope. And because Florida is mostly flat, the St. Johns River is very wide. For a good part of its length, the river is about 3 kilometers wide, far wider than the lower Mississippi River.
Many large rivers in the world, when they empty their waters in the oceans, change the temperature, salinity, and the color of these bodies of water. The fresh water of the Amazon penetrates into the Atlantic Ocean up to 200 miles. Yet, in the delta of the St. Johns River, especially in periods of low rainfall, tides may cause a reverse flow as far south as Lake Monroe, nearly 160 miles upstream.
The St. Johns, far from being the only U.S. river to flow north, isn’t even the only Florida river to do so. The Withlacoochee River flows north. But determining the precise number of north-flowing rivers isn’t a simple task. A researcher for the allexperts.com website named Thomas Baglin, using Mapquest and Mappoint, found 48 rivers in 16 states that flow north, most in Alaska (9), Washington (8), and New York (6). For some reason, he did not list Florida’s two northerly running rivers. But if included, the U.S. total increases to 50.
Matt Rosenberg, a geography “guide” at About.com, pointed out that “there are countless examples of rivers flowing northward.” He provides a list that includes those above along with Russia's Ob, Lena, and Yenisey Rivers, Canada’s Mackenzie River, and California's San Joaquin River.
Michael Onken, a Washington University graduate student who has researched north-flowing rivers, offers eight more: from Europe, the Rhine, Elba, Oder, and Vistula flow mostly northward through Germany and Poland; from Canada, the Athabasca; from South America, the Araguaia, Xingu, and Tapajos. More importantly, he argues that “over two thirds [almost 70%] of the rivers of Brazil and Bolivia flow North through the Amazon rainforest.”
L.A. Fundis, a reference librarian in West Virginia who runs a website called “Rivers that Flow North,” identified a total 117 rivers that flow north in the world -- 51 in the U.S. Using the National Geographic Society’s and Wikipedia’s online excellent color-maps, I came up with a rough estimate of the number of rivers that flow north. That tally of 245 rivers is a conservative and rough estimate.
The world’s largest north-flowing rivers are found in the remote regions of Siberia and the Amazon and Congo Basins. For example, the Yenisey, the largest river that flows north in Siberia, is even longer and more voluminous than the Mississippi. I have no doubt that most people will be surprised to learn that there are more rivers in the world running north than in any other direction.
Dr. M. Kamiar is a Professor Emeritus of geography at Florida State College at Jacksonville. He can be reached at email@example.com.
This article can be found at: https://www.metrojacksonville.com/article/2013-apr-due-north-the-st-johns-river-is-one-of-many