Kind: captions
Language: en
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the island of Greenland is covered with
an enormous ice sheet in some places two
miles thick if it all melted it's
estimated that the sea level around the
world would rise by about 20 feet for
centuries the ice year was relatively
stable but recently it's been melting
faster and faster
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nasa scientists are trying to find out
exactly how fast the glaciers of
Greenland are melting and moving water
into the sea leading the team is Josh
Willis this is a dangerous place to be
this is West Greenland 220 miles north
of the Arctic Circle and we're looking
at the Averna lick clay sure it's a
river of ice made up of snow compacted
over thousands of years and it empties
right here into the ocean at any moment
a huge chunk of ice could break off and
crush a person if they were standing
right here or cause a tidal wave that
would sweep a person away but this ice
isn't just dangerous because it's
falling the glacial flow of a Verna lick
is speeding up just like glaciers all
across the world 15 years ago this
glacier was losing ice at a speed of
about 3 feet per day according to
scientists latest measurements it has
tripled its speed now losing 10 feet per
day and it's not the only one that is
melting faster you were on the deck of a
nasa research boat called the Neptune
this is the Bernstorff you are Eric
green yo is a professor at UC Irvine and
a senior scientist on the NASA team in
the distance about 3 miles from here a
simple relation fable glacier didn't
used to be that far
it used to be much much closer in fact
about 100 years ago it was right here
the glacier retreated more in the last
15 years than in the previous 70 years
we'd like to know why this is what we
came here we think climate warming has
something to do with it and not just air
temperature because air temperature is
not enough to explain this between we
think something is happening down below
in the ocean
we're downstairs inside the boat the
computers behind me are connected to a
sonar that's scanning the shape and
depth of the seafloor that's important
because the glaciers are sitting right
in the water and water is really good at
melting the ice just imagine an ice cube
melting in a glass of water as opposed
to an ice cube left out on the counter
in the air the water is really good at
melting ice because it contains so much
heat and the warmer the water the faster
it melts so to better understand how
fast Greenland's glaciers will melt and
raise sea level scientists need to
figure out how much of that ice is
sitting underwater and how warm that
water is the NASA team is trying to
measure this from the Neptune but also
from the air
this is NASA to the Gulfstream 3 that is
my home for about five weeks a year when
we're in Greenland taking measurements
it's probably the most important
platform we have for our mission because
it allows us to get to every corner of
Greenland in just a few weeks the racks
here
communicate with the radar that we
attach to the bottom of the plane the
radar measures the ice height and tells
us which glaciers are shrinking and
retreating the fastest we also drop
probes through a tube in the back of the
plane
this is where we drop the probes through
this tube that fall to the seafloor and
measure temperature and salinity so when
we get to the right spot the pilot says
3 2 1 drop pretty soon its radioing data
back from the surface all the way to the
seafloor something we've never been able
to do before
this is what the Kangol are not a
glacier in West Greenland looks like
from the air it's about two and a half
miles wide
on both sides of the fjord you can see a
line of lighter colored rocks where ice
used to be in the last 15 years more
than five square miles of this glacier
have been lost to the sea
parts of the glacier tower a hundred and
sixty feet above the ocean but how much
of this ice is sitting in the water the
data gathered by NASA provides a clearer
picture
try looking below the water's surface it
turns out that this fjord is around a
thousand feet deep meaning that most of
the glacier is underwater and here the
deeper water is warmer the NASA research
shows that warm salty currents from the
Atlantic are eating away at the glacier
from below now this appears to be
happening to glaciers all around
Greenland scientists like Josh and Eric
think this could be one big reason why
the ice here is breaking up and melting
faster and faster
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when you look at the glacier like that
vantage point of America after it looks
like it's going to be here forever
how could it possibly go away out the
window of this helicopter is the largest
glacier in Greenland
Jakob Savin the glacier here is about 12
miles long
Jakub sovereign is world-famous because
it produces some of the biggest icebergs
and it is believed that the one that
sank the Titanic might have come from
this glacier
in the last 15 years Jakob Holland has
lost more ice than it did in the
previous century shedding 10 miles worth
of ice into the sea back in 2008
filmmakers captured an enormous chunk of
ice
away
the changes that we are witnessing are
amazing none of us expected to see such
changes in Greenland
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we are just two years into this five
year long experiment to measure how much
the oceans are melting away the ice
around the edges of Greenland but we've
already found out that glaciers all
around Greenland sit in fjords that are
much deeper than we previously knew that
means more of the ice is in contact with
the ocean water and more glaciers are
threatened than we previously understood
sometimes I think about the evidence
that we have gathered over the past 2025
years even more on the impact of climate
warming on the ice sheets and my kids
and grandkids said let me look at me and
say you knew this was happening what
have you done to slow it down I study
them and I reported the results to
people I'm not sure that was enough but
I did the best I could
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NASA's findings suggest that current
predictions of how fast Greenland's
glaciers are melting may be too
conservative putting coastal cities from
Miami to Mumbai at greater risk of
catastrophic flooding similar forces
could be at work on the other side of
the planet in Antarctica where there is
ten times as much ice
you
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you