The Antarctic Peninsula cryosphere in the instrumental period

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This page is part of the topic The ice sheet in the instrumental period

The Antarctic Peninsula north of 70°S represents less than 1% of the area of the entire grounded Antarctic ice sheet, but receives nearly 10% of its snowfall (van Lipzig et al., 2004a[1]). A third of this area lies close to the coast and below 200 m elevation, where summer temperatures are frequently above 0°C, so that this is the only part of continental Antarctica that experiences substantial summer melt. About 80% of its area is classed as a percolation zone (Rau and Braun, 2002[2]), and melt water run-off is a significant component in its mass balance (Vaughan, 2006[3]).

Beginning in the early 1990s, climatologists noted a pronounced warming trend present in the instrumental record from the Antarctic Peninsula stations (King, 1994[4]; Vaughan and Doake, 1996[5]; Skvarca et al., 1998[6]). This region has the highest density of long-term weather observations in the Antarctic, dating back to 1903 for Orcadas Station. Rates of warming on the Antarctic Peninsula are some of the fastest measured in the Southern Hemisphere (~3ºC in the last 50 years) (King, 2003[7]; Vaughan et al., 2003[8]) and there has been a clear increase in the duration and intensity of summer melting conditions by up to 74% since 1950 (Vaughan, 2006[3]).

A recent study has shown that circa 2005, the Antarctic Peninsula was contributing to global sea level rise through enhanced melt and glacier acceleration at a rate of 0.16 ± 0.06 mm/yr (which can be compared to an estimated total Antarctic Peninsula ice volume of 95,200 km3, equivalent to 242 mm of sea-level) (Pritchard and Vaughan, 2007[9]). Although it is known that Antarctic Peninsula glaciers drain a large volume of ice, it is not yet certain how much of the increased outflow is balanced by increased snow accumulation. One estimate of mass change due primarily to temperature-dependent increases in snowfall on the peninsula suggested a contribution to sea level of approximately -0.003 mm/yr (Morris and Mulvaney, 2004[10]).

Glaciers

The ice-cover on the Antarctic Peninsula is a complex alpine system of more than 400 individual glaciers that drain a high and narrow mountain plateau. The tidewater/marine glacier systems in this region (excluding ice shelves and the former tributary glaciers of Larsen A, B and Wordie ice shelves) have an area of 95,000 km2 and a mean net annual accumulation of 143 ± 29 Gt/yr (after van Lipzig et al., 2004a[1]). Changes in the ice margin around the Antarctic Peninsula based on data from 1940 to 2001 have been compiled (Ferrigno et al., 2002[11], 2006[12]; Cook et al. 2005[13]). Analysis of the results revealed that of the 244 marine glaciers that drain the ice sheet and associated islands, 212 (87%) have shown overall retreat since their earliest known position (which, on average, was 1953). The other 32 glaciers have shown overall advance, but these advances are generally small in comparison with the scale of retreats observed.

4.35 Overall change observed in glacier fronts since earliest records. (From Cook et al., 2005[13]).
4.36 Change in Antarctic Peninsula glaciers over time and by latitude. Prior to 1945 the limit of glacier retreat was north of 64°S; in 1955 it was in the interval 64-66°S; in 1960 between 66-68°S and in 1965 between 68-70°S. (from Cook et al., 2005[13]).

The glaciers that have advanced are not clustered in any pattern, but are evenly scattered down the coast (Figure 4.35). Examination of the timing of changes along the peninsula indicates that from 1945 until 1954 there were more glaciers advancing (62%) than retreating (38%). After that time, the number retreating has risen, with 75% in retreat in the period 2000-2004. The results indicate a transition between mean advance and mean retreat; a southerly migration of that transition at a time of ice shelf retreat and progressive atmospheric warming; and a clear regime of retreat which now exists across the Antarctic Peninsula (Figure 4.36). The rapidity of the migration suggests that atmospheric warming may not be the sole driver of glacier retreat in this region. Glaciers with fully grounded marine termini exhibit unusually complex responses to changing mass balance because in addition to the normal forcings they are also subject to oceanographic forcing and subglacial topography. Future analysis of changes in all boundary conditions may reveal why the glaciers have responded in this way.

A recent study of flow rates of tidewater glaciers has revealed a widespread acceleration of ice flow across the Peninsula (Pritchard and Vaughan, 2007[9]). This widespread acceleration trend was attributed not to meltwater-enhanced lubrication or increased snowfall but to a dynamic response to frontal retreat and thinning. Measurements were taken from over 300 glaciers on the west coast through nine summers from 1992 to 2005. They showed that overall flow rate increased by 10% and that this trend is greater than the seasonal variability in flow rate. A comparison of measurements between the years 1993 and 2003 only (with profiles tailored to optimize coverage in just these years) revealed a slightly greater overall acceleration of 12.4 ± 0.9%.

The loss of ice shelves (described below) has caused acceleration of the glaciers that fed them (Rignot et al., 2004a[14], 2005[15]; Rott et al., 1996[16]; Scambos et al., 2004[17]) creating locally high imbalances in ice mass. Immediately after break-up, glaciers flowing into the now-collapsed sections of the Larsen Ice Shelf accelerated to speeds of 2 to 8 times the pre-disintegration flow rate (Rignot et al., 2004a[14]; Scambos et al., 2004[17]). The glaciers flowing into the Wordie Ice Shelf also accelerated following ice shelf loss, and have been losing mass to the ocean over the last decade (Rignot et al., 2005[15]). One of these, Fleming Glacier, accelerated by about 50% during the period 1974-2003, and the region was losing mass at 18 ± 5.4 Gt/yr. A field campaign carried out in December 2008 using GPS measurements and an airborne laser survey confirmed that the glacier maintains these high flow rates and experiences a pronounced ice thinning (Wendt et al., In Press). The ice flux increase may be partially offset by increased precipitation in the western Peninsula (Turner et al., 2005b[18]), but both ice shelves (Fox and Vaughan, 2005[19]) and glaciers in the west (Pritchard and Vaughan, 2007[9]) continue to retreat. The combined estimate of mass loss (as of 2005) was 43 ± 7 Gt/yr, but a more recent assessment of the region suggests this rate has slowed (28±45 Gt/yr, Rignot et al., 2008[20]). In addition to the increase in flow rates, a recent study has revealed profound dynamic thinning of collapsed-ice shelf tributary glaciers flowing from the Antarctic Peninsula plateau to both east and west coasts (Pritchard et al., submitted). Analysis of ICESat laser altimeter data, processed along-track for the period 2003-2007, showed how surface elevation has changed over the whole of the Antarctic Peninsula. The high, central plateau and slow flowing ice caps thickened at rates as high as 1 m/yr. In contrast, some of the highest rates of thinning recorded either in Antarctica or Greenland (up to tens of metres per year) are occurring on glaciers that flowed into ice shelves that have now disappeared. Glacier tributaries feeding the intact but thinning ice shelves of Larsen C and remnants of Larsen B, plus George VI Ice Shelf and the little-studied Larsen D also thinned at rates up to several metres per year. This behaviour confirms that glaciers are very sensitive to ice shelf thinning as well as collapse, and that shelf collapse leads not just to short-term and localized adjustment but to sustained, widespread and substantial loss of grounded ice from tributary glaciers (Pritchard et al., submitted).

Ice shelves

4.37 Rapid disintegration of Larsen B ice shelf. Image on left collected on January 31, 2002 and on right collected on March 7, 2002.

Retreat of several ice shelves on either side of the Peninsula was already occurring when scientific observations began in 1903. Since that time, ice shelves on both the east and west coasts have suffered progressive retreat and some abrupt collapse (Morris and Vaughan, 2003[21]; Scambos et al., 2000[22]). Ten ice shelves have undergone retreat during the latter part of the 20th Century (Cooper, 1997[23]; Doake and Vaughan, 1991[24]; Fox and Vaughan, 2005[19]; Luchitta and Rosanova, 1998[25]; Rott et al., 1996[16], 2002[26]; Scambos et al., 2000[22], 2004[17]; Skvarca, 1994[27]; Ward, 1995[28]) (Table 4.1). Wordie Ice Shelf, the northernmost large (>1,000 km2) shelf on the western Peninsula, disintegrated in a series of fragmentations through the 1970s and 1980s, and was almost completely absent by the early 1990s. The Wordie break-up was followed in 1995 and 2002 by spectacular retreats of the two northernmost sections of the Larsen Ice Shelf (termed Larsen ‘A’ and Larsen ‘B’ by nomenclature proposed by Vaughan and Doake, 1996[5]) and the last remnant of the Prince Gustav Ice Shelf (Figure 4.37). A similar ‘disintegration’ event was observed in 1998 on the Wilkins Ice Shelf (Scambos et al., 2000[22]), but much of the calved ice remained until 2008 when dramatic calving removed about 1,400 km2 of ice. The ice bridge connecting the Wilkins Ice Shelf to Charcot Island disintegrated in early April 2009. In all these cases, persistent seasonal retreats by calving (Cooper, 1997[23]; Skvarca, 1993[29]; Vaughan, 1993[30]) culminated in catastrophic disintegrations, especially for the Larsen A (Rott et al., 1996[16]; Scambos et al., 2000[22]) and Larsen B (Scambos et al., 2003[31]).

The sequence of events leading up to the collapse of the Larsen B ice shelf suggests the processes responsible for the ultimate disintegration. In the 35-day period from 31 January 2002, satellite images recorded by the Moderate Resolution Imaging Spectroradiometer (MODIS) revealed a disintegration of a 5,700 km2 section of the Larsen B ice shelf. The January MODIS images showed that prior to its disintegration, the Larsen B ice shelf was subject to more extensive ponding of meltwater than in previous years (Scambos et al., 2004[17]). As this water drained into pre-existing crevasses, and filled them, the water pressure would have been sufficient to propagate the cracks through the entire thickness of the ice shelf (Weertman, 1973[32]; Scambos et al. 2000[22]). Satellite radar interferometry has been used with ice flow models to show that the ice shelf sped up considerably in the period before its final collapse because of weakening within its margins, perhaps as a consequence of this mechanism (Vieli et al., 2007[33]). Once the Larsen B ice shelf had disintegrated into icebergs, the forces set up as they toppled against one another drove them rapidly apart (MacAyeal et al., 2003[34]). A MODIS image taken on 7 March 2002 (Figure 4.37) shows a plume of icebergs being ejected, clearing the bay that was previously occupied by the ice shelf.

The latest results reveal an overall reduction in total ice shelf area on the Antarctic Peninsula by over 27,000 km2 in the last 50 years. As discussed in the previous section, recent findings (and studies of similar events in the southern Greenland ice sheet; see Howat et al., 2008[35]) have fostered new appreciation of the importance of floating ice on controlling ice flow, and the rapidity with which loss of floating ice could cause an acceleration in the contribution to sea level rise.

The direct cause of the Peninsula ice shelf retreats is thought by many to be a result of increased surface melting, attributed to atmospheric warming. Increased fracturing via melt-water infilling of pre-existing crevasses explains many of the observed characteristics of the break-up events (Scambos et al., 2000[22]; 2003), and melting in 2002 on the Larsen B was extreme (van den Broeke, 2005[36]).

Observations of northward-drifting icebergs support the theory that surface melt ponds or surface firn saturated with melt-water can rapidly culminate in disintegration of either ice shelves or icebergs (Scambos et al., 2004[17]).

Ice Shelf First recorded date Last recorded date Area on first
recorded date (km2)		 Area on last
recorded date (km2)		 Change (km2) % of original
area remaining		 Reference
Müller 1956 1993 80 49 -31 61 Ward (1995[28])
Wordie 1966 1989 2,000 700 -1,300 35 Doake and Vaughan (1991[24])
Wordie 1989 2009 700 96 -600 5 Wendt et al. (In Press)
Northern George VI 1974 1995 ~ 26,000 ~ 25,000 -993 96 Luchitta and Rosanova (1998[25])
Northern Wilkins 1990 1995 ~ 17,400 ~ 16,000 -1,360 92 Luchitta and Rosanova (1998[25])
1995 1998 -1,098 85 Scambos et al. (2000[22])
Jones 1947 2003 25 0 -25 0 Fox and Vaughan (2005[19])
Prince Gustav 1945 1995 2,100 ~ 100 -2,000 5 Cooper (1997[23])
1995 2000 47 2 Rott et al. (2002[26])
Larsen Inlet 1986 1989 407 0 -407 0 Rott et al. (2002[26])
Larsen A 1986 1995 2,488 320 -2,168 13 Rott et al. (1996[16])
Larsen B 1986 2000 11,500 6,831 -4,669 59 Rott et al. (2002[26])
2000 2002 3,631 -3,200 32 Scambos et al. (2004[17])
Larsen C 1976 1986 ~ 60,000 ~ 50,000 -9,200 82 Skvarca (1994[27]) and
Vaughan and Doake (1996[5])

Table 4.1 Summary of changes observed in ten ice shelves located on the Antarctic Peninsula. The figures were obtained from references that recorded the measured area of a particular ice shelf on both the earliest and most recent dates available.

Specific mechanisms of ice shelf break-up are still debated. The role of subsurface waters circulating beneath the shelves in thinning and/or warming the ice remains undetermined. Others have suggested that a change to negative surface mass balance (Rott et al., 1998[37]), or reduced fracture toughness due to a thickening temperate ice layer (Vaughan and Doake, 1996[5]), or basal melting (Shepherd et al., 2002[38]) caused the break-up. Recent modeling and observational studies have shown that the Larsen B, at least, was pre-conditioned to a retreat and breakup by faster flow, increased rifting, and detachment from the coast (Vieli et al., 2007[33]; Glasser and Scambos, 2008[39]); all these are consistent with a thinning shelf in the years leading up to disintegration.

4.38 Contours of interpolated mean annual temperature. Currently existing ice shelves are shown in grey. Portions of ice shelves that have been lost through climate-driven retreat are shown in red (From Morris and Vaughan, 2003[21]).

The pattern of ice shelf retreat on the Antarctic Peninsula appears to be consistent with the existence of a thermal limit on ice-shelf viability (Morris and Vaughan, 2003[21]; Vaughan and Doake, 1996[5]) (Figure 4.38). The limit of ice shelves known to have retreated during the last 100 years is bounded by the –5°C and –9°C isotherms (calculated for 2000 A.D.) suggesting that the retreat of ice shelves in this region is consistent with the observed warming trend of 3.5 ± 1.0°C/century (Morris and Vaughan, 2003[21]).

Sub-Antarctic Islands

Glaciers on the sub-Antarctic islands of Heard Island (53°S, 73°30’E), Kerguelen Islands (49°15’S, 69°35’E) and South Georgia (54°30’S, 36°30’W) have shown accelerating rates of retreat over the past half-century. The glaciers on Heard Island have shown extensive retreat since the 1940s (Allison and Keage, 1986[40]; Kiernan and McConnell, 1999[41], 2002[42]; Budd, 2000[43]). After a period of advance between 1963-71, most of the recession occurred since 1970 (Allison and Keage, 1986[40]). The total glacierized area has reduced by 11%, and several coastal lagoons have been formed as a result. The rapid glacier recession reflects a temperature rise on the island of about 1.3°C during the last 50 years (Budd, 2000[43]). Of the twelve major glaciers and several minor glaciers on the island, current research includes two specific examples: Stephenson Glacier and Brown Glacier. Historical records, recent observations, and geomorphological evidence indicate that rates of retreat and downwasting of the tidewater Stephenson Glacier, and concurrent expansion of ice-marginal melt-lakes, has increased by an order of magnitude since 1987 (Kiernan and McConnell, 2002[42]). In addition, Brown Glacier retreated 50 metres since 2000/01, contributing to a retreat of approximately 1.1 km since 1950 (a decrease in total volume of about 38%) (Australian Antarctic Division 2005: http://www.heardisland.aq/). Similarly at Kerguelen, glacier recession has accelerated since the early 1970s (Frenot et al., 1993[44], 1997[45]).

Glaciers, ice caps and snowfields cover over 50% of the island of South Georgia. In a recent study, the changing positions of the 103 coastal glacier fronts on South Georgia were mapped using archival aerial photographs and satellite imagery dating from the 1950s to the present (Cook et al., in submission). Of these, 97% have retreated since their earliest recorded position (which, on average, was 1961). The majority (64%) of the glaciers retreated by between 0 and 500 m since their first observations. Two glaciers stand out as having retreated the most: Neumayer Glacier by 4.4 km since 1957, and the ice front fed by Ross and Hindle Glaciers, by 2.14 km since 1960. The rate of retreat for all 103 glaciers has increased from (on average) 8 m/yr in the late 1950s, to 35 m/yr at present, revealing an accelerating rate of retreat since the 1990s. The recent rapid increase in the average rate is largely due to large increases in retreat rates of glaciers in the north-east of the island, which are currently showing an average of 60 m/yr retreat. The glaciers along the south-west coast of the island, however, are significantly different in their rate of change, due to dissimilar weather patterns caused by orographic effects (Gordon et. al., 2008). They have been in retreat slowly since the 1950s, but this has remained at a constant rate of approximately 8 m/yr. This retreat rate may now be gradually increasing, although on a much smaller scale (currently 12 m/yr). The climate records from South Georgia (recorded at Grytviken from 1905 until 1988, and subsequently from 2001 until 2008) show that in the early 1900s the summer temperatures were relatively high, lower between the 1920s to the 1940s, and higher from the 1950s to the present (Gordon et al., 2008[46]). The retreat of South Georgia glaciers over the past half-century coincides with the recent period of climate warming that began in the 1950s. Acceleration in retreat rates of glaciers on the north-east coast has occurred in the past decade as the climate has continued to warm, and although the glaciers on the south-west side have been slow to respond, their retreat rates may now also be on the increase (Cook et al., in submission).

References

  1. ↑ 1.0 1.1 Van Lipzig, N.P.M., King, J.C., Lachlan-Cope, T.A. and Van Den Broeke, M.R. 2004a. Precipitation, Sublimation and Snow Drift in the Antarctic Peninsula Region from a Regional Atmospheric Model, Journal of Geophysical Research, 109, doi 10.1029/2004JD004701.
  2. ↑ Rau, F. and Braun, M. 2002. The regional distribution of the dry-snow zone on the Antarctic Peninsula north of 70° S, Annals of Glaciology, 34, 95-100.
  3. ↑ 3.0 3.1 Vaughan, D.G. 2006. Recent trends in melting conditions on the Antarctic Peninsula and their implications for ice-sheet mass balance, Arctic, Antarctic and Alpine Research, 38, 147-152.
  4. ↑ King, J.C. 1994. Recent variability in the Antarctic Peninsula, International Journal of Climatology, 14(4), 357-369.
  5. ↑ 5.0 5.1 5.2 5.3 5.4 Vaughan, D.G. and Doake, C.S.M. 1996. Recent atmospheric warming and retreat of ice shelves on the Antarctic Peninsula, Nature, 379, 328-330.
  6. ↑ Skvarca, P., Rack, W., Rott, H., Ibarzábal, T. and Donángelo, Y. 1998. Evidence of recent climatic warming on the eastern Antarctic Peninsula, Annals of Glaciology, 27, 628-635.
  7. ↑ King, J.C. 2003. Antarctic Peninsula climate variability and its causes as revealed by analysis of instrumental records, Antarctic Peninsula Climate Variability: Historical and Paleoenvironmental Perspectives. Antarctic Research Series, 79, edited by E. Domack, et al., pp. 17-30, AGU, Washington, DC.
  8. ↑ Vaughan, D.G., Marshall, G., Connolley, W.M., Parkinson, C., Mulvaney, R., Hodgson, D.A., King, J.C., Pudsey, C.J., Turner, J. and Wolff, E. 2003. Recent rapid regional climate warming on the Antarctic Peninsula, Climatic Change, 60, 243-274.
  9. ↑ 9.0 9.1 9.2 Pritchard, H.D. and Vaughan, D.G. 2007. Widespread acceleration of tidewater glaciers on the Antarctic Peninsula, J. Geophys. Res., 112, F03S29, doi:10.1029/2006JF000597.
  10. ↑ Morris, E.M. and Mulvaney, R. 2004. Recent variations in surface mass balance of the Antarctic Peninsula Ice Sheet, J. Glaciol., 50, 257-267.
  11. ↑ Ferrigno, J.G., Williams, R.S. Jr. and Thomson, J.W. 2002. Joint U.S. Geological Survey – British Antarctic Survey Fact Sheet FS-017-02, 2p.
  12. ↑ Ferrigno, J.G., Cook, A.J., Foley, K.M., Williams, R.S. Jr., Swithinbank, C., Fox, A.J., Thomson, J.W. and Sievers, J. 2006. Coastal-Change and Glaciological Maps of the Trinity Peninsula area, Antarctica: 1843-2002 (USGS map number I-2600-A).
  13. ↑ 13.0 13.1 13.2 Cook, A., Fox, A., Vaughan, D. and Ferrigno, J. 2005, Retreating glacier fronts on the Antarctic Peninsula over the past half-century, Science, 308, 541-544.
  14. ↑ 14.0 14.1 Rignot, E., Casassa, G., Gogineni, P., Krabill, W., Rivera, A. and Thomas, R. 2004a. Accelerated ice discharge from the Antarctic Peninsula following the collapse of Larsen B ice shelf, Geophys. Res. Let., 31, doi:10.1029/2004GL020679.
  15. ↑ 15.0 15.1 Rignot, E., Casassa, G., Gogineni, P., Kanagaratnam, P., Krabill, W., Pritchard, H., Rivera, A., Thomas, R., Turner, J. and Vaughan, D.G. 2005. Recent ice loss from the Fleming and other glaciers,Wordie Bay, West Antarctic Peninsula, Geophys. Res. Let., 32, doi:10.1029/2004GL021947.
  16. ↑ 16.0 16.1 16.2 16.3 Rott, H., Skvarca, P. and Nagler, T. 1996. Rapid collapse of Northern Larsen Ice Shelf, Antarctica, Science, 271, 788-792.
  17. ↑ 17.0 17.1 17.2 17.3 17.4 17.5 Scambos, T.A., Bohlander, J., Shuman, C. and Skvarca, P. 2004. Glacier acceleration and thinner after ice shelf collapse in the Larsen B embayment, Antarctica, Geophys. Res. Lett., 31, doi:10.1029/2004GL020670.
  18. ↑ Turner, J., Lachlan-Cope, T.A., Colwell, S. and Marshall, G.J. 2005b. A positive trend in western Antarctic Peninsula precipitation over the last 50 years reflecting regional and Antarctic-wide atmospheric circulation changes, Ann. Glaciol., 41, 85-91.
  19. ↑ 19.0 19.1 19.2 Fox, A.J. and Vaughan, D.G. 2005. The retreat of Jones Ice Shelf, Antarctic Peninsula, J. Glaciol., 51(175), 555-560.
  20. ↑ Rignot, E., Bamber, J.L., Van Den Broeke, M.R., Davis, C., Yonghong, L., Van Deberg, W.J. and Van Meijgaard, E. 2008. Recent Antarctic ice mass loss from radar interferometry and regional climate modeling, Nature Geoscience, 13 January 2008; doi:10.1038/ngeo102.
  21. ↑ 21.0 21.1 21.2 21.3 Morris, E.M. and Vaughan, D.G. 2003. Spatial and temporal variation of surface temperature on the Antarctic Peninsula and the limit of viability of ice shelves, In Antarctic Peninsula Climate Variability: Historical and Paleoenvironmental Perspectives. Antarctic Research Series, 79, edited by E. Domack, et al., 61-68, AGU, Washington, DC.
  22. ↑ 22.0 22.1 22.2 22.3 22.4 22.5 22.6 Scambos, T., Huble, M., Fahnestock, M. and Bohlander, J. 2000. The link between climate warming and break-up of ice shelves in the Antarctic Peninsula, Journal of Glaciology, 46, 516-530.
  23. ↑ 23.0 23.1 23.2 Cooper, A.P.R. 1997. Historical observations of Prince Gustav Ice Shelf, Polar Record, 33(187), 285-294.
  24. ↑ 24.0 24.1 Doake, C.S.M. and Vaughan, D.G. 1991. Rapid disintegration of the Wordie Ice shelf in response to atmospheric warming, Nature, 350, 328-330.
  25. ↑ 25.0 25.1 25.2 Luchitta, B.K. and Rosanova, C.E. 1998. Retreat of northern margins of George VI and Wilkins ice shelves, Antarctic Peninsula, Ann. Glaciol., 27, 41.
  26. ↑ 26.0 26.1 26.2 26.3 Rott, H., Rack, W., Skvarca, P. and De Angelis, H. 2002. Northern Larsen Ice Shelf, Antarctica: further retreat after collapse, Annals of Glaciology, 34, 277-282.
  27. ↑ 27.0 27.1 Skvarca, P. 1994. Changes and surface features of the Larsen Ice Shelf, Antarctica, derived from Landsat and Kosmos mosaics, Ann. Glaciol., 20, 6.
  28. ↑ 28.0 28.1 Ward, C.G. 1995. Mapping ice front changes of Müller Ice Shelf, Antarctic Peninsula, Antarct. Science, 7, 197.
  29. ↑ Skvarca, P. 1993. Fast recession of the northern Larsen Ice Shelf monitored by space images, Annals of Glaciology, 17, 317-321.
  30. ↑ Vaughan, D.G. 1993. Implications of the break-up of the Wordie Ice Shelf, Antarctica for sea level rise, Antarctic Science, 5(4), 403-408.
  31. ↑ Scambos, T.A., Hulbe, C. and Fahnestock, M. 2003. Climate-induced ice shelf disintegration in the Antarcitc Peninsula. In: Antarctic Peninsula Climate Variability; Historical and Paleoenvironmental Perspectives (E. Domack, A. Burnett, A. Leventer, P. Conley, M. Kirby, and R. Bindschadler, editors), Antarctic Research Series, 79, 79-92.
  32. ↑ Weertman, J., 1973, Can a water-filled crevasse reach the bottom surface of a glacier?, International Association of Scientific Hydrology Publication, 95, 139-145.
  33. ↑ 33.0 33.1 Vieli, A., Payne, A.J., Shepherd, A. and Du, Z. 2007. Causes of pre-collapse o fthe Larsen B ice shelf: numerical modeling and assimilation of satellite observations, Earth and Planetary Science Letters, 259, 297-306, doi:10.1016/j.epsl.2007.04.50.
  34. ↑ Macayeal, D.R., Scambos, T.A., Hulbe, C.L. and Fahnestock, M.A., 2003. Catastrophic Ice-Shelf Break-Up by an Ice-Shelf-Fragment-Capsize Mechanism, J. Glaciol., 49(164) 22-36.
  35. ↑ Howat, I.M., Smith, B.E., Joughin, I. and Scambos, T.A. 2008. Rates of southeast Greenland ice volume loss from combined ICESat and ASTER observations, Geophys. Res. Lett., 35, L17505, doi:10.1029/2008GL034496.
  36. ↑ Van Den Broeke, M. 2005. Strong surface melting preceded collapse of Antarctic Peninsula ice shelf, Geophysical Research Letters, 32, L12815, doi:10.1029/2005GL023247.
  37. ↑ Rott, H., Rack, W., Nagler, T. and Skvarca, P. 1998. Climatically induced retreat and collapse of northern Larsen Ice Shelf, Antarctic Peninsula, Annals of Glaciology, 27, 86-92.
  38. ↑ Shepherd, A.P., Wingham, D.J. and Mansley, J.A.D. 2002. Inland thinning of the Amundsen Sea sector, West Antarctica, Geophys. Res. Lett., 29, 1364, doi:10.1029/2001GL014183.
  39. ↑ Glasser, N. and Scambos, T.A. 2008. A structural glaciological analysis of the 2002 Larsen B ice shelf collapse, Journal of Glaciology, 54 (184), 3-16.
  40. ↑ 40.0 40.1 Allison, I.F., Keage, P.L., 1986. Recent changes in the glaciers of Heard Island. Polar Record, 23, 255-271.
  41. ↑ Kiernan, K. and McConnell, A. 1999. Geomorphology of the sub- Antarctic Australian territory of Heard Island–McDonald Island, Australian Geographer, 30, 159-195.
  42. ↑ 42.0 42.1 Kiernan, K. and McConnell, A. 2002. Glacier retreat and melt-lake expansion at Stephenson Glacier, Heard Island World Heritage Area, Polar Record, 38, 297-308.
  43. ↑ 43.0 43.1 Budd, G.M. 2000. Changes in Heard Island glaciers, king penguins and fur seals since 1947. Papers and Proceedings of the Royal Society of Tasmania, 133, 47-60.
  44. ↑ Frenot, Y., Gloaguen, J.-C., Picot, G., Bougère, J. and Benjamin, D. 1993. Azorella selago Hook used to estimate glacier fluctuations and climatic history in the Kerguelen Islands over the last two centuries, Oecologia, 95, 140-144.
  45. ↑ Frenot, Y., Gloaguen, J.-C. and Tréhen, P. 1997. Climate change in Kerguelen Islands and colonization of recently deglaciated areas by Poa kerguelensis and P. annua. In: Battaglia, B., Valencia, J., Walton, D.W.H. (Eds.), Antarctic Communities. Species, Structure and Survival. Cambridge University Press, Cambridge, 358-366.
  46. ↑ Gordon, J.E., Haynes, V.M. and Hubbard, A. 2008. Recent glacier changes and climate trends on South Georgia, Global and Planetary Change, 60, 72-84.
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