ABSTRACT
Terrestrial geography, including the outline of continents, islands, mountain chains, and great plains, was clearly known by the mid-19th century. However, the configuration of the seafloor was unknown and, even if there had been need, no technology was capable of accurately and quickly measuring the depths of the sea. This situation began changing in the 1840s, as both scientific and commercial interests began investigating the sea. Depth measuring technology progressed from point-sounding line-and-sinker methods to primitive acoustic methods in the early 20th century. Line-and-sinker technology was capable of discovering most of the large features of the seafloor. Acoustic methods, by virtue of continual profiling with single beam systems and with 100% bottom coverage capability with multibeam swath-mapping systems, have filled in the blanks of much of the detail of the world ocean. Our present world view and understanding of Earth’s processes is a direct result of the mapping and understanding of the nature of the seafloor.
