Tim Haas, age 14, of Beaumont, Texas, for his question:
JUST WHAT IS OCEANOGRAPHY?
Oceanography is the branch of physical geography that deals with the oceans of the world. The major goals of oceanography are to understand the geologic and geochemical processes involved in the evolution and alteration of the ocean and its basins to evaluate the interaction of the ocean and the atmosphere so that greater knowledge of climatic variations can be attained and to describe how the biological productivity in the sea is controlled.
Oceanographers have a tremendously large workplace. Oceans of the world cover 71 percent of the earth's surface.
The structure and topography of the ocean floors are studied by oceanographers through the use of sonar and seismic techniques. Depths are found by measuring the time for a second wave to travel from the surface of the ocean to the bottom, and to return.
Often several returns are recorded, indicating several layers of sediment below the surface of the ocean floor.
Oceanographers have discovered that ocean floors are covered by an average thickness of sediment of up to three tenths of a mile. Some of the thickness, however, measures up to more than four miles. Some regions, particularly the central parts of the mid ocean ridges where new crust is formed, have little, if any, sediment on them.
The ocean's sediments are studied by dredging and by taking core samples. From 1968 to 1983, the Deep Sea Drilling Project, conducted by the National Science Foundation's research ship Glomar Challenger, obtained sediment columns from the ocean floor in many places. The foundation's new program, called Ocean Drilling Program, uses a ship named "JOIDES Resolution."
When oceanographers study core samples, which can represent plant and animal sediment from millions of years of deposits, they discover a continuous history of the earth's environmental changes.
The science of oceanography has many different specialties. Physical oceanographers deal with waves, currents and tides. Chemical oceanographers study the chemicals found in seawater. Marine biologists study the animals and plants of the sea. Marine geologists are concerned with the rocks beneath the sea, the sand and mud on the ocean floor and how shores are formed.
An oceanographer is really a scientific sailor. He must go to the
:ea for his information. The oceanographer works on research ships that re equipped with special instruments to study the sea and everything in it.
There are more than 5,000 oceanographers in the United States and many more will be needed in the future to work on new research vessels.
A bachelor's degree is the minimum educational requirement for a career in oceanography. For many research and teaching positions, a person must have graduate training. Many oceanographers have a doctor's degree in oceanography.