Calving fluxes and basal melt rates of Antarctic ice shelves

  title={Calving fluxes and basal melt rates of Antarctic ice shelves},
  author={Mathieu Depoorter and Jonathan L. Bamber and Jennifer A. Griggs and Jan T. M. Lenaerts and Stefan R. M. Ligtenberg and Michiel van den Broeke and Geir Moholdt},
Iceberg calving has been assumed to be the dominant cause of mass loss for the Antarctic ice sheet, with previous estimates of the calving flux exceeding 2,000 gigatonnes per year. More recently, the importance of melting by the ocean has been demonstrated close to the grounding line and near the calving front. So far, however, no study has reliably quantified the calving flux and the basal mass balance (the balance between accretion and ablation at the ice-shelf base) for the whole of… 

Ocean-driven thinning enhances iceberg calving and retreat of Antarctic ice shelves

  • Yan LiuJ. Moore F. Hui
  • Environmental Science, Geography
    Proceedings of the National Academy of Sciences
  • 2015
It is suggested that thinning associated with ocean-driven increased basal melt can trigger increased iceberg calving, implying that iceberg calve may play an overlooked role in the demise of shrinking ice shelves, and is more sensitive to ocean forcing than expected from steady state calving estimates.

Interannual variations in meltwater input to the Southern Ocean from Antarctic ice shelves

For the four largest ‘cold-water’ ice shelves, meltwater fluxes are partitioned into deep and shallow sources to reveal distinct signatures of temporal variability, providing insights into climate forcing of basal melting and the impact of this melting on the Southern Ocean.

Antarctic calving loss rivals ice-shelf thinning

Antarctica’s ice shelves help to control the flow of glacial ice as it drains into the ocean, meaning that the rate of global sea-level rise is subject to the structural integrity of these fragile,

Antarctic icebergs distributions 1992-2014: ANTARCTIC ICEBERG

Basal melting of floating ice shelves and iceberg calving constitute the two almost equal paths of freshwater flux between the Antarctic ice cap and the Southern Ocean. The largest icebergs ( 100

Antarctic icebergs distributions 1992 – 2014

Basal melting of floating ice shelves and iceberg calving constitute the two almost equal paths of freshwater flux between the Antarctic ice cap and the Southern Ocean. The largest icebergs (>100 km)

A 14-yr Circum-Antarctic Iceberg Calving Dataset Derived from Continuous Satellite Observations

Abstract. Iceberg calving is the main process that facilitates the dynamic mass loss of ice sheets into the ocean, which accounts for approximately half of the net mass loss of all Antarctic ice

Simulated melt rates for the Totten and Dalton ice shelves

The Totten Glacier is rapidly losing mass. It has been suggested that this mass loss is driven by changes in oceanic forcing; however, the details of the ice-ocean in- teraction are unknown. Here we

Melting and freezing under Antarctic ice shelves from a combination of ice-sheet modelling and observations

ABSTRACT Ice-shelf basal melting is the largest contributor to the negative mass balance of the Antarctic ice sheet. However, current implementations of ice/ocean interactions in ice-sheet models

Calving cycle of the Brunt Ice Shelf, Antarctica, driven by changes in ice shelf geometry

Abstract. Despite the potentially detrimental impact of large-scale calving events on the geometry and ice flow of the Antarctic Ice Sheet, little is known about the processes that drive rift

Ocean heat drives rapid basal melt of the Totten Ice Shelf

Change in ocean heat flux is a plausible physical mechanism to explain past and projected changes in this sector of the East Antarctic Ice Sheet and its contribution to sea level.



Melting of ice shelves and the mass balance of Antarctica

Abstract We calculate the present ice budget for Antarctica from measurements of accumulation minus iceberg calving, run-off and in situ melting beneath the floating ice shelves. The resulting

Ice-Shelf Melting Around Antarctica

Detailed glaciological estimates of ice-shelf melting around the entire continent of Antarctica show that basal melting accounts for as much mass loss as does calving, making ice- shelf melting the largest ablation process in Antarctica.

Contribution of giant icebergs to the Southern Ocean freshwater flux

[1] In the period 1979–2003 the mass of “giant” icebergs (icebergs larger than 18.5 km in length) calving from Antarctica averaged 1089 ± 300 Gt yr−1 of ice, under half the snow accumulation over the

Glaciological and Oceanographic Calculations of the Mass Balance and Oxygen Isotope Ratio of a Melting Ice Shelf

Abstract Glaciological estimates of the ice supply to George VI Ice Shelf are obtained by integrating the accumulation over the catchment. The basal melt (or possible shelf thickening) rates for the

Antarctic ice-sheet loss driven by basal melting of ice shelves

Satellite laser altimetry and modelling of the surface firn layer are used to reveal the circum-Antarctic pattern of ice-shelf thinning through increased basal melt, which implies that climate forcing through changing winds influences Antarctic ice-sheet mass balance, and hence global sea level, on annual to decadal timescales.

Ice-Ocean Interaction On Ronne Ice Shelf, Antarctica

A detailed glaciological study of Ronne Ice Shelf has been undertaken along a flowline extending from Rutford Ice Stream grounding line to the ice front. Measurements of velocity, surface elevation,

Extensive dynamic thinning on the margins of the Greenland and Antarctic ice sheets

Many glaciers along the margins of the Greenland and Antarctic ice sheets are accelerating and, for this reason, contribute increasingly to global sea-level rise. Globally, ice losses contribute ∼1.8

Twenty-first-century warming of a large Antarctic ice-shelf cavity by a redirected coastal current

It is shown that a redirection of the coastal current into thefilchner Trough and underneath the Filchner–Ronne Ice Shelf during the second half of the twenty-first century would lead to increased movement of warm waters into the deep southern ice-shelf cavity, which would boost average basal melting from 0.2 metres to almost 4 metres per year.

Free-Drifting Icebergs: Hot Spots of Chemical and Biological Enrichment in the Weddell Sea

It is suggested that free-drifting icebergs can substantially affect the pelagic ecosystem of the Southern Ocean and can serve as areas of enhanced production and sequestration of organic carbon to the deep sea.

Lower satellite-gravimetry estimates of Antarctic sea-level contribution

A new model of GIA is adopted, developed from geological constraints, which produces GIA rates systematically lower than those of previous models, and an improved fit to independent uplift data is applied, finding that West Antarctica is nearly in balance and that East Antarctica is gaining substantial mass.