A new three-dimensional map from the U.S. Geological Survey in Menlo Park, California, shows the Los Angeles basin as it has never been seen before. Marine geologist Jim Gardner used high-resolution sonar to pick out details as small as a foot wide on the ocean floor. "The resolution was high enough that we could pick out all sorts of things that had been dumped," Gardner says. "There were lots of old pipes and drilling equipment scattered across the seafloor."
The panoramic view above, looking northeast toward downtown L.A., combines three years of soundings made by a research ship. Gardner hopes his data will help track the migration of toxic waste dumped at sea and to locate faults that could cause earthquakes.