National Geographic 1975 05 Mayo Cbz de Revista
The French- American Mid- Ocean Undersea Study sends scientists two miles down to the Mid- Atlantic Ridge. U. S. leader James R. Heirtzler defines its fissured, lava- shaped central valley. Geologist Robert D. Ballard takes you into the rift. Photographs b, y FAMOUS and the National Geographic photographer Emory Kristof.