New Orleans Before and After Katrina

On Aug. 27, 2005, the city of New Orleans sat peacefully between the shore of Lake Pontchartrain and the Mississippi River.

But by the morning of Aug. 30, 2005 the city was as much as 80 percent flooded, largely because its surrounding levees failed to hold against Hurricane Katrina's massive storm surge. And the flooding is only getting worse as water from Lake Pontchartrain continues to leak into the city.

These images were taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra Satellite. In the earlier image, New Orleans formed a tan and green grid between the lake shore and the river.

Three days later, dark water covered the eastern half of the city and widespread flooding is visible throughout the region. Lake Pontchartrain and Lake Maurepas have nearly merged into a single body, separated only by a narrow strip of land.

The images are shown in false color to make water visible against the land. Water is black or dark blue where it is colored with mud, vegetation is bright green, and clouds are light blue and white.

--Bjorn Carey

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Credit: NASA GSFC