Geology of Earth's Seabed: Interactive Digital Map Shows Depth of Basins

Observe the long, slashing volcanic ridge across the wide Pacific, and zoom in on color-coded areas of the seafloor composed of "sponge spicules," shells and coral fragments, or "mixed calcareous -siliceous ooze," why don't you. It's among the possibilities with the first digital geology map of the seafloor, which covers 70 percent of the Earth's surface. The data are now available open-access online--complete with a globe you can turn and control by clicking. 

Researchers from University of Sydney (USYD)'s School of Geosciences and elsewhere recently published their findings in the journal Geology. This is the first mapping of the seafloor since the 1970s, when a map was hand drawn. The map will allow scientists to better understand how oceans have responded, and will respond, to climate change. It also turns out that the deep ocean basins are more complicated places than previously thought, according to a statement.

"The deep ocean floor is a graveyard with much of it made up of the remains of microscopic sea creatures called phytoplankton, which thrive in sunlit surface waters. The composition of these remains can help decipher how oceans have responded in the past to climate change," said lead researcher Dr. Adriana Dutkiewicz, USYD, in the release. 

The type of phytoplankton called diatoms, for instance, are responsible for about one-quarter of the oxygen we breathe. Their contribution to fighting global warming is larger than that of most plants on land. When diatoms die, they sink to the ocean floor, locking away the carbon, the release noted.

In the new geology map, researchers learned that diatom accumulations on the seafloor are almost entirely separate from diatom blooms in the Southern Ocean's surface waters. This shows that we understand carbon's source but not its sink, noted Professor Dietmar Muller, USYD, in the release.

Many of the new results are from the ocean floor near Australia. For instance, the Southern Ocean was formerly thought to be covered by clay blown off the continent-but the current map shows it to be a patchwork of microfossil leftovers. Data from the project was collected from 15,000 seafloor samples taken over 50 years on research cruise ships, the release said.

To see the open-access maps and materials, including a globe you can spin by clicking it, go here. 

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