The station lies at 71 ° 57» S and 23 ° 20» E, 220 km due South from
the edge of the ice shelf.
Schematic cartoon of a glacier flowing into an ice shelf, showing the grounding line and calving at the ice cliff at
the edge of the ice shelf.
During a flight over the Pine Island Glacier ice shelf, the DC - 8 banks over the Amundsen Sea and the clean
edge of the ice shelf front.
Lead author of the study Joseph MacGregor said in a statement: «Typically, the leading
edge of an ice shelf moves forward steadily over time, retreating episodically when an iceberg calves off (breaks off and floats out to sea), but that is not what happened along the shear margins.»
Not exact matches
More than once we had lost one
of our four engines, and in 1987 a giant crack became persistently visible along the
edge of the Larsen B
ice shelf, off the Antarctic Peninsula — making it abundantly clear that an emergency landing would be no gentle touchdown.
Scientists have drilled into one
of the most isolated depths in all
of the world's oceans: a hidden shore
of Antarctica that sits under 740 meters
of ice, hundreds
of kilometers in from the sea
edge of a major Antarctic
ice shelf.
This isolated cavity
of seawater, down at the grounding zone, sits deep beneath the back corner
of the
ice shelf — 850 kilometers back from where the
edge of the
ice meets the open sea.
Break up
of a floating «
ice shelf» in front
of the glacier left tall
ice «cliffs» at its
edge.
«The
ice shelf generally breaks at points that are between a half and full thickness
of the
ice sheet from the
edge,» summarises Christmann.
Floating
ice shelves mark the outermost
edges of an
ice sheet and line nearly half the Antarctic coastline.
Ice shelves (the floating front
edges of glaciers that extend tens to hundreds
of miles offshore) melt more because
of contact with ocean water below them than they do because
of sunlight.
That's because it appears that most
of the action is happening beneath the
ice shelves — those giant plains
of floating
ice that cling to the continent's
edges.
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.
The Larsen C
ice shelf is 217 miles thick and sits at the
edge of West Antarctica, holding back the flow
of glaciers feeding into it.
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.
One reason, as other Antarctic research has shown, is that the speed
of loss
of Antarctic
ice is to a large extent not a function
of air temperature in any case, but
of ocean heat intruding beneath the vast
shelves of floating
ice around the
edges.
From your link: «In some instances, bright red spots or streaks along the
edge of the continent show where icebergs calved or
ice shelves disintegrated, meaning the satellite began seeing warmer ocean water where there had previously been
ice.»
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.
These authors postulated an extended Barents Sea
Ice Sheet, the western part of the huge Eurasian Ice Sheet51, 55, that had reached the shelf edge causing polynya - like open - water conditions (triggered by strong katabatic winds) with phytoplankton and sea ice algae production, subglacial meltwater outflow and the deposition of suspended material on the slope at site PS2138 -
Ice Sheet, the western part
of the huge Eurasian
Ice Sheet51, 55, that had reached the shelf edge causing polynya - like open - water conditions (triggered by strong katabatic winds) with phytoplankton and sea ice algae production, subglacial meltwater outflow and the deposition of suspended material on the slope at site PS2138 -
Ice Sheet51, 55, that had reached the
shelf edge causing polynya - like open - water conditions (triggered by strong katabatic winds) with phytoplankton and sea
ice algae production, subglacial meltwater outflow and the deposition of suspended material on the slope at site PS2138 -
ice algae production, subglacial meltwater outflow and the deposition
of suspended material on the slope at site PS2138 - 2.
The study also found that the Southern Ocean Circumpolar Current, which helps determine sea -
ice extent, is steered by submerged ridges and canyons along the
edge of the Antarctic continental
shelf, rather than by global warming or other climatic conditions.
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 bel
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 bel
ice shelves (the
edges of the
ice sheet which extend over the ocean) from bel
ice sheet which extend over the ocean) from below.
Eventually, the leading
edge forms a cantilevered
ice shelf that floats on the water but remains attached to the anchored part
of the
ice sheet.
Warmer water has been detected closer to the
edges of Antarctica in recent years, and that can accelerate the melting
of ice shelves from below.
Where the
ice shelves have collapsed some
of the glaciers have apparently tripled their speed so on the
edges there is a downward grade in spots (as evidenced from the topology map...
The answer is that since the effect
of CO2 is at the surface, rather than distributed throughout the troposphere, then the surface
of the Antarctic
ice shelves melted supplying fresh water to the sea
ice edge.