The last complete map was hand-drawn in the 1970s.
But
now, following half a century of research collating around 15,000
samples from research ships, the University of Sydney's School of
Geosciences has developed an unprecedented impression of the world in
stunning detail.
The
map, published in the latest edition of Geology, offers fresh insights
into the depths of the world's oceans, which make up 70 per cent of the
Earth's surface, and how they have been affected by climate change.
Crucially, researchers found, much of the seafloor is not covered in clay but a 'complex patchwork of microfossil remains'.
To emphasise
the sheer scale of the data, lead researcher Dr Adriana Dutkiewicz
teamed up with National ICT Australia (NICTA) big data experts to use
algorithms to develop an interactive 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.
While
researchers have recently experimented with satellite data-gathering to
build impressions of the Earth's surface, this method - acoustic beams
from ships - is deemed to be the most accurate.
Dr Dutkiewicz said the primary benefit of this research will be to enhance our understanding of 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,'
said Dr Dutkiewicz.
'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... We urgently need to
understand how the ocean responds to climate change.'
It
will also pave the way for marine research voyages 'aimed at better
understanding the workings and history of the marine carbon cycle,' Dr
Dutkiewicz added. Some speculate it will even be useful for oil
exploration.
Much
of North America, particularly on the West side, is surrounded by
siliceous mud, a sediment commonly made up of phytoplankton shells.
Australasia's
landscape became a key focus of the study as the data quickly began to
disprove much of what scientists believe to be true about the region.
The seafloor they found, is complex, deep and covered in microfossil remains.
According
to the map, which shows an aura of light blue around Australia, the sea
bed is largely made up of calcareous ooze, which is a calcium carbonate
mud formed from free-floating organisms. The research team will now set
their sights on the relationship between this part of the ocean bed and
the surface waters to understand the significance.
'Australia's
new research vessel Investigator is ideally placed to further
investigate the impact of environmental change on diatom [the most
common form of phytoplankton] productivity,' said Dr Dutkiewicz.
'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.
'Life in the Southern Ocean is much richer than previously thought.'
The
digital map comes after a landmark study in 2014, when researchers at
the University of California, San Diego, used satellites to build
impressions of mountains - 'seamounts' - which lie beneath miles of
sediment on the ocean floor.
The 2014 study laid bare the lack of information on the buried tectonic structures.
Previously
unseen features include newly exposed continental connections across
South America and Africa, and new evidence for seafloor spreading ridges
at the Gulf of Mexico that were active 150 million years ago.
Dating for everyone is here: ❤❤❤ Link 1 ❤❤❤
ΑπάντησηΔιαγραφήDirect sexchat: ❤❤❤ Link 2 ❤❤❤
ZW .