First ever digital map of seafloor’s geology created

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Over 40 years after the most recent hand drawn map of composition of the Earth’s seafloor was created, researchers have created a digital map of seafloor’s geology.

The digital map – a collaborative effort of scientists led by University of Sydney’s School of Geosciences, is the first ever attempt at mapping the seafloor’s geology in digital version. The map has been published in the latest edition of journal Geology and is available here.

Published in the latest edition of Geology, the map reveals the complexity of deep ocean basins. Researchers say that the map will enable other scientists better understand how our oceans have responded, and will respond, to environmental 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,” says lead researcher Dr Adriana Dutkiewicz from the University of Sydney. “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.”

Researchers reveal in the latest study that phytoplankton called diatoms are responsible for production of quarter of the oxygen we breathe and are at the forefront of the fight against global warming with their contribution much larger than most terrestrial plants on land. Their dead remains sink to the bottom of the ocean, locking away their carbon.

The new map demonstrates that diatom accumulations on the seafloor are nearly entirely independent of diatom blooms in surface waters in the Southern Ocean. Researchers say that this particular disconnect reveals that we may understand the carbon source, but do not understand the sink.

Professor Dietmar Muller from the University of Sydney suggested that more research in this arena is required to better understand this relationship.

The map and the accompanying research will pave way for future marine research voyages aimed at better understanding the workings and history of the marine carbon cycle.

Researchers note in their report that some of the most significant changes to the seafloor map are in the oceans surrounding Australia. Previous map suggested that much of the Southern Ocean around Australia is mainly covered by clay blown off the continent, however, the latest map shows that this area is actually a complex patchwork of microfossil remains.

“Life in the Southern Ocean is much richer than previously thought”, said Dr Dutkiewicz.

Dr Dutkiewicz and colleagues analysed and categorised around 15,000 seafloor samples – taken over half a century on research cruise ships to generate the data for the map. She teamed with the National ICT Australia (NICTA) big data experts to find the best way to use algorithms to turn this multitude of point observations into a continuous digital map.

“Recent images of Pluto’s icy plains are spectacular, but the process of unveiling the hidden geological secrets of the abyssal plains of our own planet was equally full of surprises!” co-author Dr Simon O’Callaghan from NICTA said.