From our readers SSE and Sea Floor Mapping Guy Cochrane Dr. Guy R. Cochrane, Marine Geophysicist Coastal and Marine Geology Research Program of the U.S. Geological Survey During the Sustainable Seas Expedition project dives are planned in an area north of Anacapa Island, where a joint U.S. Geological Survey and Channel Islands National Marine Sanctuary habitat mapping project is underway. USGS side-scan sonar record north of Anacapa Island, June 1998. This is a one square kilometer image of the seafloor surface. Dark areas indicate hard rock layers, while lighter areas show softer rock. The tree-ring pattern on the sea floor is the result of wave erosion.
Submersibles are valuable tools for exploring the ocean environment.
Many discoveries in the fields of marine biology and geology would not have been made without them. On land, aerial photography and satellite remote sensing solve the visibility problem. Unfortunately, these techniques do not apply well to the undersea domain except in very shallow or very clear water. The first patent for an echo ranging sonar was filed at the British Patent Office by L. F. Richardson, one month after the sinking of the Titanic. The theory behind sonar is that echoes are stronger when sound bounces off hard surfaces or surfaces that are at right angles to the sound source.