Massive canyon discovered buried under Greenland ice
A vast gorge in the Earth on the
same scale as the Grand Canyon
lies buried under ice in Greenland,
scientists have learned.
The massive hidden canyon is at
least 466 miles (740km) long and
up to 800 metres (2,600ft) deep in
places.
The feature, resembling a
meandering river channel, is
believed to pre-date the ice sheet
that has covered Greenland for
millions of years.
Prof
Jonathan
Bamber,
from the
school of
geographical studies at the
University of Bristol, said: "With
Google Streetview available for
many cities around the world and
digital maps for everything from
population density to happiness,
one might assume that the
landscape of the Earth has been
fully explored and mapped.
"Our research shows there's still a
lot left to discover."
The canyon was uncovered by
airborne radar which can
penetrate ice and bounce off the
land beneath.
Scientists pieced together radar
measurements covering thousands
of kilometres collected by Arctic
researchers over several decades.
They found evidence of a fissure in
the bedrock stretching northwards
almost from the centre of
Greenland.
The canyon ends in a deep fjord
connecting it to the Arctic ocean.
Prof David Vaughan, from the
British Antarctic Survey based in
Cambridge, another member of the
team whose findings appear in the
journal Science, said: "A discovery
of this nature shows that the Earth
has not yet given up all its secrets.
A 750km canyon preserved under
the ice for millions of years is a
breathtaking find in itself, but this
research is also important in
furthering our understanding of
Greenland's past.
"This area's ice sheet contributes to
sea level rise and this work can
help us put current changes in
context."
Co-author Dr Michael Studinger,
from the US space agency Nasa's
Goddard space flight centre, said:
"It is quite remarkable that a
750km-long channel the size of
parts of the Grand Canyon is
discovered in the 21st century
below the Greenland ice sheet. It
shows how little we still know
about the bedrock below large
continental ice sheets."
The canyon is believed to play an
important role transporting sub-
glacial meltwater from Greenland's
interior to the edge of the ice sheet,
and ultimately to the ocean.
Even before the ice sheet appeared,
at least 4 million years ago, the
canyon probably provided a major
pathway for flowing water.
