Floating ice shelves mark the outermost
edges of an ice sheet and line nearly half the Antarctic coastline.
«There have been many efforts over the years to photograph
the edge of the ice sheet, for many purposes,» he added.
Researchers at the University of Washington and the University of Edinburgh used data from the European Space Agency's CryoSat - 2 to identify a sudden drainage of large pools below Thwaites Glacier, one of two fast - moving glaciers at
the edge of the ice sheet.
Especially in West Antarctica, where much of the ice sheet sits below sea level, complex interactions at
the edge of the ice sheet can sensitively affect the rate of ice - sheet retreat.
The caves in the limestone gorge of Creswell Crags have provided archaeologists with important evidence of human activity towards the end of the last Ice Age when the area was right at
the edge of the ice sheet.
Thomas, I appreciate that they are imperfect things to compare, but have you ever seen pictures of the ice pack near
the edge of the ice sheet where the melting is happening fastest?
Around
the edges of the ice sheet, though, there is accelerated melting.
Collecting data from NASA's satellite Gravity and Recovery Climate Experiment, known as GRACE, and GPS measurements of the bedrock on
the edges of the ice sheet, the Denmark Technical Institute's National Space Institute in Copenhagen was able to show that crustal uplift due to ice loss has gone up by 1.5 inches between October 2005 and August 2009 along the northwest coast, a change that study co-author John Wahr calls «very dramatic».
In these areas, the location of
the edge of the ice sheet is very sensitive to both ocean condition and the amount of ice fracturing (crevasses or rifts).
If a relatively small chunk of ice currently plugging
the edge of an ice sheet in Antarctica were to melt, it could release massive amounts of ice into the ocean that would significantly increase global sea level for the next 10,000 years, according to a new report.
In fact, 2005 looks to feature the greatest amount of melting of
the edge of the ice sheet in Greenland in about 30 years (or more):
This ocean will be incredibly important for sea level rise, because the easiest way to destabilise the Antarctic Ice Sheet is to warm up the ocean and melt the ice shelves (
the edges of the ice sheet which extend over the ocean) from below.
Especially in West Antarctica, where much of the ice sheet sits below sea level, complex interactions at
the edge of the ice sheet can sensitively affect the rate of ice - sheet retreat.
And it's partly driven by rising ocean temperatures, as warmer water chews away at
the edges of the ice sheet.
An hour after taking off from an airstrip about 90 km from the western
edge of the ice sheet, the helicopter lands on flat, dry, crunchy snow.
Dust trapped over the centuries has become concentrated at the melting
edge of the ice sheet.
Long, roughly parallel cracks score the surface, formed by water and pressure; impossibly blue lakes of meltwater fill depressions; and veiny networks of azure streams meander west, flowing to
the edge of the ice sheet and eventually out to sea.
«Now that we have mapped the whole
edge of the ice sheet, it rules out any chance that parts of Antarctica are advancing.
Not exact matches
-- On a lower speed, add eggs one at a time and vanilla until well incorporated — Increase mixing speed to high and let it go for 10 minutes — the mixture will become really pale and will almost double in size — In a medium sized bowl, whisk together flour, baking powder, baking soda, and salt — When 10 minutes are up, add flour mixture slowly until just combined, about 45 - 60 seconds — Chop up and mix together all
of your baking and snack ingredients in a small bowl, and fold into batter with a spatula until just incorporated — Using a medium - sized
ice cream scoop, portion cookie dough on parchment paper - lined cookie
sheet and wrap the entire thing tightly with plastic wrap — Refrigerate for a minimum
of 1 hour and up to 1 week — Heat oven to 400F and arrange cookies on cookie
sheets at least 4 ″ apart — Bake 9 - 11 minutes, until they are golden in color and slightly brown along the
edges — Cool the cookies completely on the
sheet pan (or just eat them immediately...)
1) Mix flour, butter and
icing sugar in a bowl using two knives to cut the butter until the mixture resembles fine breadcrumbs 2) Add in the egg yolks and vanilla extracts and mix well, then add
iced water until the dough starts to come together 3) Shape the dough into a ball on a cool, flat, floured surface 4) Flatten dough into a disc and then wrap in plastic wrap, and chill in the refrigerator for at least 30 minutes 5) Meanwhile, peel, core and slice the apples into as thin slices as possible 6) Mix sugar and ground cinnamon powder with sliced apples and let it rest for a while 7) Pre-heat oven to 180 deg cel 8) Once dough has chilled, roll pastry dough on a
sheet of parchment paper until it has expanded to the size
of the tart mold (I used a rough mold the size
of a large pizza) 9) Leaving at least an inch
of dough free, arrange apple slices by overlapping them slightly in the shape
of a circle, starting from the outermost part
of the circle, until you reach the inside 10) Fold the
edges of dough over the filling and then sprinkle the dough with a bit
of sugar 11) Bake for about 40 - 45 minutes, or until the crust is golden brown and the apples are soft 12) Serve warm, with a side
of whipped cream or
ice cream (optional)
The Dry Valleys are a line
of nearly snow - and
ice - free valleys in the West Antarctic Ice Sheet at the edge of the Ross Ice She
ice - free valleys in the West Antarctic
Ice Sheet at the edge of the Ross Ice She
Ice Sheet at the
edge of the Ross
Ice She
Ice Shelf.
The
edge of America's
ice sheet — marked by a line
of rubble called the terminal moraine — ran along Long Island.
But the thing is, [the
ice sheet] kind
of stops right there at the
edge [
of South America], especially down around Cape Horn and those islands down there — those were not glaciated at last glacier maximum.
«The
ice shelf generally breaks at points that are between a half and full thickness
of the
ice sheet from the
edge,» summarises Christmann.
Research by the UK Centre for Polar Observation and Modelling (CPOM) at the University
of Leeds has produced the first complete map
of how the
ice sheet's submarine
edge, or «grounding line,» is shifting.
Highlights included field trips to the
ice edge and Bratina Island, an upside - down piece
of seafloor now frozen in the
ice sheet, where we collected samples from hypersaline ponds filled with all domains
of life: archaea, bacteria, and eukaryota.
The research team found the evidence confirming the stability
of the East Antarctic
ice sheet at an altitude
of 6,200 feet, about 400 miles from the South Pole at the
edge of what's called the polar plateau, a flat, high surface
of the
ice sheet covering much
of East Antarctica.
Melting near the
edges of the Greenland
ice sheet, where the surface is below 4,000 feet, causes about half
of its annual
ice loss.
The great
ice sheets of Greenland and Antarctica, which rise to over 13,000 feet above sea level, accumulate
ice over most
of their surfaces and melt only at their lower elevations near the
edges.
Professor Poinar continues, «Mammoths were much better at adapting to new habitats than we first thought — we suspect that subgroups
of mammoths evolved to deal with local conditions, but maintained genetic continuity by encountering and potentially interbreeding with each other where their two different habitats met, such as at the
edge of glaciers and
ice sheets.»
These new measurements confirm what some
of the more pessimistic scientists thought: The melting along the crucial
edges of the two major
ice sheets is accelerating and is in a self - feeding loop.
Using 50 million laser readings from a NASA satellite, scientists for the first time calculated changes in the height
of the vulnerable but massive
ice sheets and found them especially worse at their
edges.
To track the growth and retreat
of ice cover in the region, Miller and colleagues have been hunting for remnants
of scraggly mosses along the
edges of the island's retreating
ice sheets.
Ice shelves are floating masses of ice on the edge of the continental ice she
Ice shelves are floating masses
of ice on the edge of the continental ice she
ice on the
edge of the continental
ice she
ice sheet.
Using satellite images and other data, the team studied the
edge of the former Laurentide
Ice Sheet, a vast expanse of ice that covered two - thirds of North America during the last ice a
Ice Sheet, a vast expanse
of ice that covered two - thirds of North America during the last ice a
ice that covered two - thirds
of North America during the last
ice a
ice age.
«Most
ice cores are collected from the middle
of the
ice sheet where it rarely ever melts, or on the
ice sheet edge where the meltwater flows into the ocean,» Karina Graeter, the lead author
of the study as a graduate student in Dartmouth's Department
of Earth Sciences, said in a statement.
At this pit on Mars, the steep slope at the northern
edge (toward the top
of the image) exposes a cross-section
of a thick
sheet of underground water
ice.
This is because a bit
of extra heat in summer is a very efficient way to get rid
of ice...» applies equally to what appears to be happening with respect to ablation on the low altitude edges of the Greenland Ice She
ice...» applies equally to what appears to be happening with respect to ablation on the low altitude
edges of the Greenland
Ice She
Ice Sheet.
Other factors would include: — albedo shifts (both from
ice > water, and from increased biological activity, and from
edge melt revealing more land, and from more old dust coming to the surface...); — direct effect
of CO2 on
ice (the former weakens the latter); — increasing, and increasingly warm, rain fall on
ice; — «stuck» weather systems bringing more and more warm tropical air ever further toward the poles; — melting
of sea
ice shelf increasing mobility
of glaciers; — sea water getting under parts
of the
ice sheets where the base is below sea level; — melt water lubricating the
ice sheet base; — changes in ocean currents -LRB-?)
The rates
of rapid rise Jim Hansen talks about occurred when large
ice sheets covered Canada and the Antarctic
ice sheet extended to the
edge of the continental shelf.
So, as the leading
edge melts, this deformation and filling would be first observed as a thinning
of the
sheet and, in particular, the trunk or main
ice stream channel, as well as an acceleration
of the stream.
This is in fact increasingly observed around the
edges of Greenland and Antarctica in recent years: outlet glaciers and
ice streams that drain the
ice sheets have greatly accelerated their flow.
Considering what I've learned in the nine years since I got to visit the frigid summit and eroding
edges of Greenland's amazing
ice sheet, in a final note to Alley here's how I described my reply to the Climate Desk's «Can We Save Greenland?»
Even prior to any large feedback involving the
ice sheets or carbon cycle, the actual rise in sea - level continues to be at the top
edge of the envelope
of the IPCC's predictions.
But without the
ice shelves to impede the flow
of glacial
ice, typically moving 400 — 900 meters a year, the flow
of ice from the continent could accelerate, leading to a thinning
of the
ice sheet on the
edges of the Antarctic continent.
Unlike the formerly - glaciated regions
of the Northern Hemisphere, 98 %
of Antarctic bedrock remains covered by
ice and the
ice sheet edge is fringed by extensive
ice shelves; this hampers the collection
of data on
ice history and introduces substantial uncertainty in reconstructions.
Generally yes, but there has been a lot
of new information learned since the IPCC Third Assessment Report (e.g., on trends in hurricane intensity, the accelerated melting back
of Arctic sea
ice, the intensifying deterioration of the edges of the Greenland Ice Sheet, etc.) and Gore's presentation of the science has been updated to account for these, drawing from what are the really highly reviewed and high quality papers by leading scientis
ice, the intensifying deterioration
of the
edges of the Greenland
Ice Sheet, etc.) and Gore's presentation of the science has been updated to account for these, drawing from what are the really highly reviewed and high quality papers by leading scientis
Ice Sheet, etc.) and Gore's presentation
of the science has been updated to account for these, drawing from what are the really highly reviewed and high quality papers by leading scientists.
-- Susan Solomon, Nature The Long Thaw is written for anyone who wishes to know what cutting -
edge science tells us about the modern issue
of global warming and its effects on the pathways
of atmospheric chemistry, as well as global and regional temperatures, rainfall, sea level, Arctic sea -
ice coverage, melting
of the continental
ice sheets, cyclonic storm frequency and intensity and ocean acidification.
This small outlet glacier south
of Jakobshavn Isbrae is moving
ice from the interior
of the
ice sheet out to the
ice sheet edge (top right), where the
ice calves off into the ocean.
In a new study, Box and a team
of researchers describe the decline in
ice sheet reflectivity and the reasons behind it, noting that if current trends continue, the area
of ice that melts during the summer season is likely to expand to cover all
of Greenland for the first time in the observational record, rather than just the lower elevations at the
edges of the continent, as is the case today.