Seafloor Sunday #80: Satellite Mapping of the Seafloor

This week's Seafloor Sunday image is a nice perspective image showing the eastern U.S., Caribbean, northeast South America, and the Mid-Atlantic Ridge from NOAA's Environmental Visualization Laboratory website.

I love these images that depict the Earth's curvature -- as if you are orbiting an Earth and able to see through the ocean. In fact, this image was produced by a satellite that does just that:

This image shows a view of the Northwest Atlantic using data from the ERS-1 and Geosat satellites, analyzed by NOAA's Laboratory for Satellite Altimetry. These satellites send radar pulses from space to the surface of Earth. Slight differences in elevation can be detected on land, as accurately as 1 inch. Mapping the ocean bottom is similarly done - areas where ocean mountains occur make the ocean surface bulge at those points. Likewise, where trenches occur, the ocean surface is depressed. These gravitational anomalies are recorded by the satellites and converted to height measurements, resulting in the map shown here.

While these data are certainly not as high-resolution as ship-based sonar (e.g., multibeam bathymetry), they are fantastic for visualizing huge areas of our seafloor in a single, seamless map.

Image: National Oceanic and Atmospheric Administration (NOAA) / Altimetric Bathymetry