A new digital map of the seafloor debunks an earlier belief that the seafloor is mainly covered with clay. The digital seafloor map will allow scientists to understand the ocean composition and how it helps the ocean react to climate change.
"In order to understand environmental change in the oceans we need to better understand what is preserved in the geological record in the seabed," Dr Adriana Dutkiewicz, study lead author from the University of Sydney, said in the news release.
"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."
The researchers built the digital seafloor map using nearly 14,500 samples. They stitched the images using big-data algorithms to produce a continuous map. The map appears color-coded to show the variations in the seafloor composition. Light green represents the "diatom ooze" (mix of mud and diatom bits), blue is the "calcareous ooze" (mud and calcium carbonate from microscopic shelled animals), brown for clay, red for volcanic ash and gravel, and yellow for sand, according to the LiveScience.
One of the significant changes observed invovled the waters surrounding Australia. The old map showed that they were mainly clay but the new map revealed plankton graveyards.
"The old map suggests much of the Southern Ocean around Australia is mainly covered by clay blown off the continent, whereas our map shows this area is actually a complex patchwork of microfossil remains," said Dr Dutkiewicz. "Life in the Southern Ocean is much richer than previously thought."
Plankton graveyards are actually beneficial to Earth because they keep 20 percent of the carbon dioxide away from the atmosphere, which it thought to help mitigate global warming.
Details of the study were published in the August 9 issue of the journal Geology. You can also view the online map here.
