ABSTRACT
Technology has been the key to mankind's understanding of the ocean floor since earliest times, in the same way that it has to our knowledge of the surface of other planets. Essentially primitive technologies, such as the lead-line sounding used in HMS Challenger (see Chapter 1), have in the twentieth century given way to widespread use, first of single-beam echosounding, then of multi-beam echo-sounding, and now of interpretations based on satellite altimetry Our knowledge of the topography of two-thirds of our planet's surface more than one mile deep has increased exponentially as a result and is now truly global, though questions remain about the veracity of the altimeter interpretations of bathymetry in areas poorly charted by ships. Even so, the detail we have is nowehere near as fine as it is for the surfaces of Mars and the Moon, which have been photographed by space missions. Since shape is the first clue to process, this rise in application of technology, and a concomitant rise in topographic resolution, have revolutionized our understanding of seabed processes in ways undreamed of even thirty years ago, as addressed by Tony Laughton in Chapter 5.
