Cochise College           Student Papers in Geology

Geology Home Page                   physical geology  historical geology  planetary  gems           

Roger Weller, geology instructor

ocean floor
by Trevor Behr
Physical Geology
Fall 2016

Mapping Ocean Floors

            As a species, humans have held onto a strong sense of curiosity throughout the short time they have existed on this planet called Earth.  Through that curiosity they have discovered fire, created nuclear energy, and cured mass epidemic diseases and all of these discoveries had a specific set of directions leading them.  It is for this curiosity that humans have plans on how to build great skyscrapers and how to tie one’s own shoes, but the greatest map of all time has yet to be completed.  The earliest remnants of modern day humans chalk up to being about 200,000 years old and our recorded civilization being only 6,000 years of that, one would think there would be somewhat of a complete map of the planet they exist on (Howell).

            In fact, humans actually only have about one third of the entire Earth’s surfaces mapped.  This is calculated by knowing that the continents and land masses of Earth have been 90% explored, leaving places like the Amazon Rainforest, Antarctica, and large deserts to still be discovered.  With the largest missing piece being that people have only explored and mapped about 5% of the entire ocean (Peters).  Being that the ocean makes up 70% of the Earth, leads us back to the notion that only about 30.5% of Earth has been mapped thus far.

            The task of mapping the ocean floor seemed simple in theory, but the combined efforts of geologists and measurements from ship sonar and satellite graphing still struggled to create a completely accurate map.  This turned to be so challenging that people had known more features of the Moon than they did their planet’s own ocean.  A group of geophysicist had set out to correct such a notion, with the aid of U.S. Navy’s satellites and ships and partnership with the National Oceanic and Atmospheric Administration (NOAA).  Their idea was to use the satellites to help measure the amount of gravitation tension surrounding all parts of the Earth.  From those measurements they would predict depths of the ocean is specific areas and double check and correct those measurements with the sonar from the Navy’s ships.


  Gravitational pressure on the ocean (NASA). 2014

            Since satellites could not sense the bottom of the ocean, microwaves were bounced off the ocean’s surface to measure the body of water’s shape.  This would put in place both the distance from Earth the satellite was and what portion of the Earth the satellite was viewing.  Before being able to measure the depths of the entire ocean through satellites, scientists only mapped major shipping and travel routes between continents using hydrography.  Hydrography, by definition, is being the science of surveying and charting bodies of water.  A part of the surveying process called bathymetry was used to map the inner most edges of continents for ship traffic by using sonar. This same method was also used to double check the satellite gravity readings.  


“Bathymetry map of East Flower Garden Bank” (NOAA).

            Knowing more of how the ocean floor is structured helps scientists predict and study continental drift and plate tectonics more thoroughly.  Since the undersea mapping had begun the NOAA has continued their discoveries and researching into things such as lithospheric structure, mapping of undersea volcanoes, and mining exploration of petroleum (Sandwell).  Of course this mapping process will also help to further identify changes in sea levels and the identification of possible new landmasses.

            There are still some problems with current ocean mapping, such as that satellites cannot recognize ocean features smaller than 12 kilometers across.  This still puts a lot of guess work into mapping, David Monahan explains this, “It's like drawing a map of a city, where you know a lot about one street, then nothing for 10 miles, then a lot about another street” (Mackenzie).  Another example would be that, you know one street has buildings on it, and three streets down has building on it, so you would assume that in between these two points the other streets should have buildings.

            In conclusion, underwater mapping has yet to be near to completion, but has made great efforts to do so.  As people strive to go further into space and Mars, people will also try to reach deeper depths closer to our planet’s core.  The more technologically advanced the human race becomes, the more they will learn of the planet they call home.  One day there should be a complete map of Earth as scientists and exploiters continues to discover new hidden spaces of the planet.  It is said that since the mapping of our oceans that the total space covered may soon be up to 15% (Fox).     


Works Cited

Fox, Paul J. "Upheaval from the Abyss: Ocean Floor Mapping and the Earth Science  Revolution.
" Bulletin of the American Meteorological Society 84.5 (2003): 671-4.   
ProQuest. Web. 21 Nov. 2016.

Howell, Elizabeth. "How Long Have Humans Been On Earth? - Universe Today."
Universe Today. N.p., 23 Dec. 2015. Web. 21 Nov. 2016.

Mackenzie, Dana. "Ocean Floor is Laid Bare by New Satellite Data." Science 277.5334 (1997):
1921. ProQuest. Web. 21 Nov. 2016.

NASA. "Seafloor Features Are Revealed by the Gravity Field." NASA. NASA, 29 Dec. 2015.
Web. 21 Nov. 2016.

Peters, Colleen. "The Ocean: Haven't We Already Mapped It? - Schmidt Ocean Institute."    
Schmidt Ocean Institute. N.p., 12 Mar. 2013. Web. 21 Nov. 2016.

Sandwell, David T. "Estimated and Predicted Sea Floor Topography from Satellite Altimetry."    
National Centers For Environmental Information. U.S. Department of Commerce, 1995.       
Web. 21 Nov. 2016.