Texas A&M University
Department of Oceanography
Winter 1998 / Spring 1999 - Vol. 6, No. 3
A complete map of the seafloor?
HOW LOW CAN YOU GO?
Side-scan sonars and multibeam echo sounders each use different sound frequencies for different applications.
Although you would think that multibeam echo sounders
and side-scan sonars would have allowed scientists to map most of the ocean
basins by now, sadly this hasn't happened. The problem is mainly that the
oceans are just plain big.
A multibeam mapping ship moving at 10 knots (about 11.5
mph) in 3,000 meters of water can cover about 111 square kilometers in an
hour. But the oceans have an area of about 3.6 x 108 square kilometers,
implying it would take that ship on the order of 371 years to finish the
job. Ouch.
Academic scientists collect data to learn about how
the seafloor got to be the way it is. Many more industry oceanographers
just need to know the depth and shape. The offshore high-resolution seafloor
mapping industry is booming because of the need to emplace oil rigs, build
pipelines, lay fiber-optic cables, map harbor entrances, and dredge waterways.
Needless to say, offshore mapping is a robust area of
employment for oceanographers, and probably will be for some time. 
Dr. Will Sager is a professor and head of the geological oceanography section of the Department of Oceanography at Texas A&M University. His e-mail address is wsager@ ocean.tamu.edu.
http://oceanography.tamu.edu/Quarterdeck/1998/3/sager-7.html
Copyright 1998-1999, Department
of Oceanography, Texas A&M University.
Updated November 24, 1998. (abdw)
Send Quarterdeck inquiries to quarterdeck@ocean.tamu.edu.
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