More than two-thirds of the earth’s surface is covered by deep oceans, yet researchers know one hundred times more about the topography of Mars than about the seafloor. While ship-based surveys provide a high resolution of the ocean’s floor, the amount of coverage by ships represents a very small fraction of the total surface area and it would require 100-200 years of survey time to map the entire ocean. Fortunately, researchers are able to use remote sensing to access the more remote areas of the ocean floor to create a complete map of the world’s oceans. Variations in the topography of the ocean floor affects the gravitational pull which can be captured by radar altimeters on satellites.
The new map created from satellite data has exposed the existence of thousands of previously unknown ocean mountains. The latest ocean map has twice the resolution of the last global seafloor map which was created twenty years ago. The map was created using data pulled from European Space Agency’s (ESA) CryoSat-2 satellite and NASA’s Jason-1 satellite to measure gravity on the ocean floor. The remote sensing techniques used to create the map allows researchers to see below mile-thick layers of ocean sediment to understand tectonics of the ocean including continental connections.
KML files of marine gravity anomaly, vertical gravity gradient, and gravity error are available for download from the Exploring Ocean Tectonics from Space site.
References
Sandwell, D. T., R. D. Müller, W. H. F. Smith, E. Garcia, R. Francis, New global marine gravity model from CryoSat-2 and Jason-1 reveals buried tectonic structure, Science, Vol. 346, no. 6205, pp. 65-67, doi: 10.1126/science.1258213, 2014.
“New Map Exposes Previously Unseen Details of Seafloor.” Scripps Institution of Oceanography, UC San Diego |. N.p., 2 Oct. 2014. Web. 06 Oct. 2014. <https://scripps.ucsd.edu/news/new-map-exposes-previously-unseen-details-seafloor>.
