Sediment in the Gulf of Mexico
acquired May 17, 2011 download large image (3 MB, JPEG, 3840x2880)
Sediment in the Gulf of Mexico
acquired May 22, 2011 download large image (2 MB, JPEG, 3840x2880)

Besides inundating floodplains, agricultural fields, and homes, the flooded Mississippi and Atchafalaya Rivers delivered huge sediment loads to the Gulf of Mexico in the spring of 2011. At least some of that sediment could be seen from space.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured the top image on May 17, 2011, roughly when the first pulse of sediment arrived in the Gulf. The bottom image is from May 22, 2011. Sediment varies in color from tan to green, and is most apparent around the Mississippi Delta and the Atchafalaya Bay.

The Morganza Floodway was opened on May 14 to ease flooding on the Mississippi River by diverting some water through the Atchafalaya River channel. Peak discharge through the floodway occurred from May 18 to 22. Despite some cloud cover on May 22, spreading sediment is clearly visible in the Gulf of Mexico, especially west of Vermillion Bay.

Each year, the Gulf of Mexico experiences low-oxygen conditions, or hypoxia, that can lead to substantial marine-life loss. Hypoxia is caused by excessive water-borne nutrients (particularly nitrogen), which mostly arise from fertilizer use on farms and lawns.

Known as a dead zone, the hypoxic area in the Gulf of Mexico is not new, but flooding in 2011 was expected to make it worse than usual. In mid-June, a team of NOAA-supported scientists announced that spring flooding could lead to the largest dead zone in the Gulf of Mexico since mapping began in 1985. The average dead zone size over the past five years has been 6,000 square miles. In 2011, the researchers said, the area could measure from 8,500 to 9,421 square miles, about the size of New Hampshire.

  1. References

  2. U.S. National Oceanic and Atmospheric Administration. (2011, June 14). Major flooding on the Mississippi river predicted to cause largest Gulf of Mexico dead zone ever recorded. Accessed June 23, 2011.

NASA images courtesy MODIS Rapid Response Team, Goddard Space Flight Center. Caption by Michon Scott.

Aqua - MODIS

Sediment in the Gulf of Mexico

Image Location
Image Location
More in this Event (view all)
Early Spring Floods in Indiana High Waters along the Ohio and Mississippi Rivers Rising Waters on the Mississippi River Rising Waters on the Minnesota and Mississippi Rivers Rising Waters on the James River Retreating Snow and Advancing Water in the Upper Midwest Receding Snow Sets Stage for Floods near Fargo Spring Flooding in the Upper Midwest Rising Rivers in the U.S. Midwest Rising Waters along the Red River Spring Floods in Saskatchewan Spring Flooding in Manitoba Heavy Rain in Central United States Flooding along the Mississippi River Continued Flooding along the Mississippi Flooding along the James River, South Dakota Flooding in Wake of Levee Breach Spring Floods in the U.S. Midwest and Canada Flooding along the Wabash and Ohio Rivers Flooding at the Junction of the Mississippi and Ohio Rivers Floods Spread South along the Mississippi River High Waters along the Mississippi River Floods Continue along the Mississippi River Flooding Continues along the Red River Flooding in Memphis Flooding in Arkansas Flooding reaches Vicksburg, Mississippi Morganza Floodway, 1973 Floodwaters near Natchez Rising Waters on the Lower Mississippi Morganza Spillway Opens in Louisiana Mississippi Floods in Arkansas and Tennessee Mississippi Floods in Missouri and Tennessee Flooding near New Madrid, Missouri Water in the Morganza Floodway Morganza Floodway after Five Days of Flow Mississippi Floods near Vicksburg Sediment Plume in Lake Pontchartrain Lingering Floods along the Mississippi River Lower Mississippi River Remains Swollen Waters Spread Across Floodway above Morgan City Lay of the Land Between Old River and the Mississippi Floodwaters Recede along Wabash and Ohio Rivers Floodwaters Retreat from Birds Point-New Madrid Floodway Lingering Floods in Louisiana Morganza Floodway Lingering Floodwaters near Vicksburg, Mississippi Sediment from the Mississippi Floods Floods Recede around the Wabash-Ohio Confluence