There’s a new digital map limning the composition of the seafloor, a major factor in global climate change, and it’s shown evidence of “microfossil” graveyards off the coast of Australia, in addition to other complex deep-ocean geology.
SEAFLOOR GRAVEYARD IS AVAILABLE ONLINE
The interactive map is actually available via the online journal Geology, published August 9th. This marks a first at creating an extensive, comprehensive map in the past 40 years. There hasn’t been a single attempt at such a map since the 1970s, which the University of Sydney has announced was drawn by hand. Back then, the impetus to understand how the planet reacts to global climate change wasn’t so great, either.
“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 study author Adriana Dutkiewicz, a sedimentologist at the University of Sydney in a statement. “Life in the Southern Ocean is much richer than previously thought.”
SECRET TO GLOBAL CLIMATE CHANGE AVERSION IN DEAD DIATOMS
The microfossils discovered are actually from a type of phytoplankton that takes in carbon dioxide and excretes oxygen. Known as diatoms, these phytoplankton take roughly 20% of breathable oxygen in the air, air we need to breathe. When they die, diatoms sink down to the dark musty abyssal of the oceans, dragging all the their carbon with them. This process is referred to as “carbon sink,” and it helps prevent the renown greenhouse gas carbon dioxide from spreading into and warming the planet’s fragile atmosphere.
The new map also showed scientists that masses of dead diatoms are resting in the Southern Ocean, which are not where diatoms ordinarily bloom on the ocean surface. Continuing our studies of these underwater distributions of dead diatoms will help us come to understand how oceans reacted to eras of greater climate change in the past, said Dutkiewicz. Color coding (visible on the map) represents what composes the seafloor from region to region: light green is “diatom ooze,” which is a mix of mud and diatom bits; blue is “calcareous ooze,” which is mud and calcium carbonate from microscopic shelled animals; and brown is simply clay. Red spots are volcanic ash and gravel, and yellow is sand.
DATA COLLECTION & MAP MAKING
So far the data incorporated to construct a map of the 15,000 seafloor samples has been collected exclusively from research cruises. After the ventures, big-data algorithms were used to synthesize the data into one contiguous map.
Dutkiewicz is excited that for this new map to guide future research missions.
“Australia’s new research vessel ‘Investigator’ is ideally placed to further investigate the impact of environmental change on diatom productivity,” she explained. “We urgently need to understand how the ocean responds to climate change.”