2.2: Eras of Oceanographic Exploration

The exploration of the sea can be divided, somewhat arbitrarily, into various eras (Wust, 1964). I have extended his divisions through the end of the 20th century.

1. Era of Surface Oceanography: Earliest times to 1873. The era is characterized by systematic collection of mariners’ observations of winds, currents, waves, temperature, and other phenomena observable from the deck of sailing ships. Notable examples include Halley’s charts of the trade winds, Franklin’s map of the Gulf Stream, and Matthew Fontaine Maury’s Physical Geography of the Sea.
2. Era of Deep-Sea Exploration: 1873–1914. Characterized by a few, wide-ranging oceanographic expeditions to survey surface and subsurface conditions, especially near colonial claims. The major example is the Challenger Expedition (figure \(\PageIndex{1}\)), but also the Gazelle and Fram Expeditions.

   

   Figure \(\PageIndex{1}\): Example from the era of deep-sea exploration: Track of H.M.S. Challenger during the British Challenger Expedition, 1872–1876. After Wust (1964).

3. Era of National Systematic Surveys: 1925–1940. Characterized by detailed surveys of colonial areas. Examples include Meteor surveys of the Atlantic (figure \(\PageIndex{2}\)), and the Discovery Expeditions.

   

   Figure \(\PageIndex{2}\): Example of a survey from the era of national systematic surveys. Track of the R/V Meteor during the German Meteor Expedition. Redrawn from Wust (1964).

4. Era of New Methods: 1947–1956. Characterized by long surveys using new instruments (figure \(\PageIndex{3}\)). Examples include seismic surveys of the Atlantic by Vema leading to Heezen’s maps of the sea floor.

   

   Figure \(\PageIndex{3}\): Example from the era of new methods. The cruises of the R/V Atlantis out of Woods Hole Oceanographic Institution. After Wust (1964).

5. Era of International Cooperation: 1957–1978. Characterized by multinational surveys of ocean and studies of oceanic processes. Examples include the Atlantic Polar Front Program, the norpac cruises, the International Geophysical Year cruises, and the International Decade of Ocean Exploration (figure \(\PageIndex{4}\)). Multiship studies of oceanic processes include mode, polymode, norpax, and jasin experiments.

   

   Figure \(\PageIndex{4}\): Example from the era of international cooperation. Sections measured by the International Geophysical Year Atlantic Program, 1957-1959. After Wust (1964).

6. Era of Satellites: 1978–1995. Characterized by global surveys of oceanic processes from space. Examples include Seasat, noaa 6–10, nimbus–7, Geosat, Topex/Poseidon, and ers–1 & 2.
7. Era of Earth System Science: 1995– Characterized by global studies of the interaction of biological, chemical, and physical processes in the ocean and atmosphere and on land using in situ (which means from measurements made in the water) and space data in numerical models. Oceanic examples include the World Ocean Circulation Experiment (woce) (figure \(\PageIndex{5}\)) and Topex/Poseidon (figure \(\PageIndex{6}\)), the Joint Global Ocean Flux Study (JGOFS), the Global Ocean Data Assimilation Experiment (GODAE), and the SeaWiFS, Aqua, and Terra satellites.

   

   Figure \(\PageIndex{5}\): Tracks of research ships making a one-time global survey of the ocean of the world. From World Ocean Circulation Experiment.

   

   Figure \(\PageIndex{6}\): Example from the era of satellites. Topex/Poseidon tracks in the Pacific Ocean during a 10-day repeat of the orbit. From Topex/Poseidon Project.