As the Mississippi River enters the Gulf of Mexico, it deposits its load of sediment in a delta.
Click on image for full size
Credit: NASA

Changing the Mississippi River Could Lead to New Land near New Orleans
News story originally written on October 20, 2009

Around the city of New Orleans, the land has been sinking and the level of the sea has been rising. These changes mean that large areas of land have disappeared.

The concrete levees on either side of the Mississippi River keep water from flooding the land. That’s a good thing but they also cause the river water to move too fast to drop the sand mud, and gravel sediments that it carries. Those sediments carried by the river build up the land when they drop out. When the river doesn’t drop them, the land disappears even faster.

Scientists were looking for a way to get the river to drop the sediments making more land. Using a computer model, they discovered how to build-up new land by allowing water to flow beyond the levees of the Mississippi River. They studied how the river carries sediment and deposits it areas where the flowing water slows. The build up of these sediments creates land.

The scientists’ model looks at how allowing water to spill out of the levees through two openings would affect the land. The model shows that the water would slow down as it gets beyond the levees, depositing sediment and helping to build up the land.

The changes to the river's path would not solve the problem of disappearing land in the New Orleans area, but they would help slow the loss of land.

Last modified January 21, 2010 by Lisa Gardiner.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Sea Level

Sea level is the height of the ocean surface. Scientists measure sea level to figure out how much sea level rise is happening now because of global warming. If you tried to draw a flat line at the top...more

Rivers

Rivers are very important to Earth because they are major forces that shape the landscape. Also, they provide transportation and water for drinking, washing and farming. Rivers can flow on land or underground...more

Step 2: Sediments on the Move!

If you sneeze into a pile of dust the little particles fly everywhere, but if you sneeze into a pile of rocks, they will stay put. It takes more force than a sneeze to move those rocks. Winds and water...more

Step 3: Sediments Settling Down!

When water or wind slows down, sediment can no longer be carried in it. The particles of sediment fall through the water or air and form a blanket of sediment on the bottom of a river, a lake, ocean,...more

Triggers of Volcanic Eruptions in Oregon's Mount Hood Investigated

Scientists have learned that Mount Hood, Oregon's tallest mountain, has erupted in the past due to the mixing of two different types of magma. Adam Kent, a geologist at Oregon State University, says this...more

Oldest Earth Mantle Reservoir Discovered

The Earth's mantle is a rocky, solid shell that is between the Earth's crust and the outer core. The mantle is made up of many different reservoirs that have different chemical compositions. Scientists...more

It’s Not Your Fault – A Typical Fault, Geologically Speaking, That Is

Some faults look strong and like they wouldn’t cause an earthquake. But it turns out that they can slip and slide like weak faults causing earthquakes. Scientists have been looking at one of these faults...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA