Beautiful seafloor landforms indicate past Antarctic grounding-line retreat of kilometers per twelve months
A rapidly retreat
Are the rates at which we be taught ice shelves jumpy this day representative of how rapidly they shrank prior to now? Dowdeswell et al. characterize observations of the Antarctic seafloor that indicate the presence of submarine grounding-zone wedges on the Larsen continental shelf (be taught the Level of view by Jakobsson). The authors elaborate these ridges as being precipitated by the tidal upward push and fall of the ice shelf at the grounding line, which squeezes the underlying sediments when it rests on the seafloor. From this, they calculated that ice shelf retreat at this convey about 14,000 years ago turned into once every so incessantly as great as 100 times as rapidly because the sensible over the past 10,000 years.
Abstract
A attach of grounding-line landforms on the Antarctic seafloor, imaged at submeter horizontal resolution from an self reliant underwater vehicle, enables calculation of ice sheet retreat rates from a advanced of grounding-zone wedges on the Larsen continental shelf, western Weddell Sea. The landforms are aloof sets of as much as 90 ridges, <1.5 meters high and spaced 20 to 25 meters apart. We interpret these ridges as the product of squeezing up of soft sediment during the rise and fall of the retreating ice sheet grounding line during successive tidal cycles. Grounding-line retreat rates of 40 to 50 meters per day (>10 kilometers per twelve months) are inferred at some level of regional deglaciation of the Larsen shelf. If repeated this day, such rapidly mass loss to the ocean would bear sure implications for rising the velocity of world sea level upward push.