Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation


Our understanding of the deglacial evolution of the Antarctic Ice Sheet (AIS) following the Last Glacial Maximum (26,000–19,000 years ago)1 is based largely on a few well-dated but temporally and geographically restricted terrestrial and shallow-marine sequences2,3,4. This sparseness limits our understanding of the dominant feedbacks between the AIS, Southern Hemisphere climate and global sea level. Marine records of iceberg-rafted debris (IBRD) provide a nearly continuous signal of ice-sheet dynamics and variability. IBRD records from the North Atlantic Ocean have been widely used to reconstruct variability in Northern Hemisphere ice sheets5, but comparable records from the Southern Ocean of the AIS are lacking because of the low resolution and large dating uncertainties in existing sediment cores. Here we present two well-dated, high-resolution IBRD records that capture a spatially integrated signal of AIS variability during the last deglaciation. We document eight events of increased iceberg flux from various parts of the AIS between 20,000 and 9,000 years ago, in marked contrast to previous scenarios which identified the main AIS retreat as occurring after meltwater pulse 1A3,6,7,8 and continuing into the late Holocene epoch. The highest IBRD flux occurred 14,600 years ago, providing the first direct evidence for an Antarctic contribution to meltwater pulse 1A. Climate model simulations with AIS freshwater forcing identify a positive feedback between poleward transport of Circumpolar Deep Water, subsurface warming and AIS melt, suggesting that small perturbations to the ice sheet can be substantially enhanced, providing a possible mechanism for rapid sea-level rise.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Location map.
Figure 2: Climate development from the Last Glacial Maximum to the Holocene (25–7 kyr ago).
Figure 3: IBRD flux in the Scotia Sea compared to climate changes during the last deglaciation.
Figure 4: Three-dimensional pattern of temperature anomalies at 14.8–14 kyr ago (AID6).


  1. 1

    Clark, P. U. et al. The Last Glacial Maximum. Science 325, 710–714 (2009)

    CAS  ADS  PubMed  PubMed Central  Google Scholar 

  2. 2

    Heroy, D. C. & Anderson, J. B. Radiocarbon constraints on Antarctic Peninsula ice sheet retreat following the Last Glacial Maximum. Quat. Sci. Rev. 26, 3286–3297 (2007)

    ADS  Google Scholar 

  3. 3

    Mackintosh, A. et al. Retreat of the East Antarctic ice sheet during the last glacial termination. Nature Geosci. 4, 195–202 (2011)

    CAS  ADS  Google Scholar 

  4. 4

    Weber, M. E. et al. Interhemispheric ice-sheet synchronicity during the Last Glacial Maximum. Science 334, 1265–1269 (2011)

    CAS  ADS  PubMed  Google Scholar 

  5. 5

    Bond, G. C. & Lotti, R. Iceberg discharges into the North Atlantic on millennial timescales during the last glaciation. Science 267, 1005–1010 (1995)

    CAS  ADS  PubMed  Google Scholar 

  6. 6

    Peltier, W. R. Global glacial isostasy and the surface of the ice-age Earth: the ICE-5G (VM2) model and GRACE. Annu. Rev. Earth Planet. Sci. 32, 111–149 (2004)

    CAS  ADS  Google Scholar 

  7. 7

    Bentley, M. J. et al. Deglacial history of the West Antarctic Ice Sheet in the Weddell Sea embayment: constraints on past ice volume change. Geology 38, 411–414 (2010)

    ADS  Google Scholar 

  8. 8

    Conway, H., Hall, B. L., Denton, G. H., Gades, A. M. & Waddington, E. D. Past and future grounding-line retreat of the West Antarctic ice sheet. Science 286, 280–283 (1999)

    CAS  PubMed  Google Scholar 

  9. 9

    Gladstone, R. M., Bigg, G. R. & Nicholls, K. W. Iceberg trajectory modeling and meltwater injection in the Southern Ocean. J. Geophys. Res. 106, 19903–19915 (2001)

    ADS  Google Scholar 

  10. 10

    Silva, T. A. M., Bigg, G. R. & Nicholls, K. W. Contribution of giant icebergs to the Southern Ocean freshwater flux. J. Geophys. Res. 111, C03004 (2006)

    ADS  Google Scholar 

  11. 11

    Stuart, K. M. & Long, D. G. Tracking large tabular icebergs using the SeaWinds Ku-band microwave scatterometer. Deep Sea Res. II 58, 1285–1300 (2011)

    ADS  Google Scholar 

  12. 12

    Weber, M. E. et al. Dust transport from Patagonia to Antarctica—a new stratigraphic approach from the Scotia Sea and its implications for the last glacial cycle. Quat. Sci. Rev. 36, 177–188 (2012)

    ADS  Google Scholar 

  13. 13

    EPICA Community Members. One-to-one coupling of glacial climate variability in Greenland and Antarctica. Nature 444, 195–198 (2006)

  14. 14

    Schmitt, J. et al. Carbon isotope constraints on the deglacial CO2 rise from ice cores. Science 336, 711–714 (2012)

    CAS  ADS  PubMed  PubMed Central  Google Scholar 

  15. 15

    Deschamps, P. et al. Ice-sheet collapse and sea-level rise at the Bølling warming 14,600 years ago. Nature 483, 559–564 (2012)

    CAS  ADS  PubMed  PubMed Central  Google Scholar 

  16. 16

    Clark, P. U., Mitrovica, J. X., Milne, G. A. & Tamisiea, M. E. Sea-level fingerprinting as a direct test for the source of global meltwater pulse IA. Science 295, 2438–2441 (2002)

    CAS  ADS  PubMed  Google Scholar 

  17. 17

    Golledge, N. R., Fogwill, C. J., Mackintosh, A. N. & Buckley, K. M. Dynamics of the Last Glacial Maximum Antarctic ice-sheet and its response to ocean forcing. Proc. Natl Acad. Sci. USA 109, 16052–16056 (2012)

    CAS  ADS  PubMed  Google Scholar 

  18. 18

    Menviel, L., Timmermann, A., Timm, O. E. & Mouchet, A. Climate and biogeochemical response to a rapid melting of the West Antarctic ice sheet during interglacials and implications for future climate. Paleoceanography 25, PA4231 (2010)

    ADS  Google Scholar 

  19. 19

    Bintanja, R., van Oldenborgh, G. J., Drijfhout, S. S., Wouters, B. & Katsman, C. A. Important role for ocean warming and increased ice-shelf melt in Antarctic sea-ice expansion. Nature Geosci. 6, 376–379 (2013)

    CAS  ADS  Google Scholar 

  20. 20

    Peltier, W. R. & Fairbanks, R. G. Global glacial ice volume and Last Glacial Maximum duration from an extended Barbados sea level record. Quat. Sci. Rev. 25, 3322–3337 (2006)

    ADS  Google Scholar 

  21. 21

    Bard, E., Hamelin, B. & Delanghe-Sabatier, D. Deglacial meltwater pulse 1B and Younger Dryas sea levels revisited with boreholes at Tahiti. Science 327, 1235–1237 (2010)

    CAS  ADS  PubMed  Google Scholar 

  22. 22

    Marshall, S. J. & Koutnik, M. R. Ice sheet action versus reaction: distinguishing between Heinrich events and Dansgaard-Oeschger cycles in the North Atlantic. Paleoceanography 21, PA2021 (2006)

    ADS  Google Scholar 

  23. 23

    Pritchard, H. D. et al. Antarctic ice-sheet loss driven by basal melting of ice shelves. Nature 484, 502–505 (2012)

    CAS  ADS  Google Scholar 

  24. 24

    Jenkins, A. et al. Observations beneath Pine Island Glacier in West Antarctica and implications for its retreat. Nature Geosci. 3, 468–472 (2010)

    CAS  ADS  Google Scholar 

  25. 25

    Hellmer, H. H., Kauker, F., Timmermann, R., Determann, J. & Rae, J. Twenty-first-century warming of a large Antarctic ice-shelf cavity by a redirected coastal current. Nature 485, 225–228 (2012)

    CAS  ADS  Google Scholar 

  26. 26

    Gladstone, R. M. et al. Calibrated prediction of Pine Island Glacier retreat during the 21st and 22nd centuries with a coupled flowline model. Earth Planet. Sci. Lett. 333–334, 191–199 (2012)

    ADS  Google Scholar 

  27. 27

    Fischer, H. et al. Reconstruction of millennial changes in dust emission, transport and regional sea ice coverage using the deep EPICA ice cores from the Atlantic and Indian Ocean sector of Antarctica. Earth Planet. Sci. Lett. 260, 340–354 (2007)

    CAS  ADS  Google Scholar 

  28. 28

    Anderson, R. F. et al. Wind-driven upwelling in the Southern Ocean and the deglacial rise in atmospheric CO2 . Science 323, 1443–1448 (2009)

    CAS  ADS  Google Scholar 

  29. 29

    Sprenk, D. et al. Southern Ocean bioproductivity during the last glacial cycle—new decadal-scale insight from the Scotia Sea. Geol. Soc. Lond. Spec. Publ. 381, 245–261 (2013)

    ADS  Google Scholar 

  30. 30

    NGRIP Members. High-resolution record of Northern Hemisphere climate extending into the last interglacial period. Nature 431, 147–151 (2004)

  31. 31

    Weber, M. E., Niessen, F., Kuhn, G. & Wiedicke, M. Calibration and application of marine sedimentary physical properties using a multi-sensor core logger. Mar. Geol. 136, 151–172 (1997)

    CAS  ADS  Google Scholar 

  32. 32

    Jansen, J. H. F., Van der Gaast, S. J., Koster, B. & Vaars, A. J. CORTEX, a shipboard XRF-scanner for element analyses in split sediment cores. Mar. Geol. 151, 143–153 (1998)

    CAS  ADS  Google Scholar 

  33. 33

    Richter, T. O. et al. The Avaatech XRF Core Scanner: technical description and applications to NE Atlantic sediments. Geol. Soc. Lond. Spec. Publ. 267, 39–50 (2006)

    CAS  ADS  Google Scholar 

  34. 34

    Weber, M. E. Estimation of biogenic carbonate and opal by continuous non-destructive measurements in deep-sea sediments: application to the eastern Equatorial Pacific. Deep Sea Res. I 45, 1955–1975 (1998)

    CAS  ADS  Google Scholar 

  35. 35

    Weber, M. E. et al. BMPix and PEAK tools: new methods for automated laminae recognition and counting—application to glacial varves from Antarctic marine sediment. Geochem. Geophys. Geosyst. 11, 1–18 (2010)

    Google Scholar 

  36. 36

    Müller, P. J. & Schneider, R. An automated leaching method for the determination of opal in sediments and particulate matter. Deep Sea Res. I 40, 425–444 (1993)

    Google Scholar 

  37. 37

    Rosén, P. et al. Fourier transform infrared spectroscopy, a new method for rapid determination of total organic and inorganic carbon and biogenic silica concentration in lake sediments. J. Paleolimnol. 43, 247–259 (2010)

    ADS  Google Scholar 

  38. 38

    Kanfoush, S. l. et al. Millennial-scale instability of the Antarctic Ice Sheet during the last glaciation. Science 288, 1815–1819 (2000)

    CAS  ADS  Google Scholar 

  39. 39

    Martínez-Garcia, A. et al. Southern Ocean dust-climate coupling over the past four million years. Nature 476, 312–315 (2011)

    ADS  Google Scholar 

  40. 40

    Lamy, F. et al. Increased dust deposition in the Pacific Southern Ocean during glacial periods. Science 343, 403–407 (2014)

    CAS  ADS  PubMed  Google Scholar 

  41. 41

    Hofmann, A. Kurzfristige Klimaschwankungen im Scotiameer und Ergebnisse zur Kalbungsgeschichte der Antarktis während der letzten 200 000 Jahre (Rapid climate oscillations in the Scotia Sea and results of the calving history of Antarctica during the last 200000 years) PhD thesis (Univ. Bremen, 1999)

    Google Scholar 

  42. 42

    Diekmann, B. et al. Terrigenous sediment supply in the Scotia Sea (Southern Ocean): response to Late Quaternary ice dynamics in Patagonia and on the Antarctic Peninsula. Palaeogeogr. Palaeoclimatol. Palaeoecol. 162, 357–387 (2000)

    Google Scholar 

  43. 43

    Yoon, H. I., Khim, B. K., Yoo, K. C., Bak, Y. S. & Lee, J. I. Late glacial to Holocene climatic and oceanographic record of sediment facies from the South Scotia Sea off the northern Antarctic Peninsula. Deep Sea Res. II 54, 2367–2387 (2007)

    ADS  Google Scholar 

  44. 44

    Pugh, R. S., McCave, I. N., Hillenbrand, C. D. & Kuhn, G. Circum-Antarctic age modelling of Quaternary marine cores under the Antarctic Circumpolar Current: ice-core dust–magnetic correlation. Earth Planet. Sci. Lett. 284, 113–123 (2009)

    CAS  ADS  Google Scholar 

  45. 45

    Lisiecki, L. E. & Raymo, M. E. A. Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records. Paleoceanography 20, PA1003 (2005)

    ADS  Google Scholar 

  46. 46

    Parrenin, F. et al. The EDC3 chronology for the EPICA Dome C ice core. Clim. Past 3, 485–497 (2007)

    Google Scholar 

  47. 47

    Ruth, U. et al. “EDML1”: a chronology for the EPICA deep ice core from Dronning Maud Land, Antarctica, over the last 150 000 years. Clim. Past 3, 475–484 (2007)

    Google Scholar 

  48. 48

    Rasmussen, S. O. et al. A new Greenland ice core chronology for the last glacial termination. J. Geophys. Res. 111, D06102 (2006)

    ADS  Google Scholar 

  49. 49

    Lemieux-Dudon, B. d. et al. Consistent dating for Antarctic and Greenland ice cores. Quat. Sci. Rev. 29, 8–20 (2010)

    ADS  Google Scholar 

  50. 50

    Veres, D. et al. The Antarctic ice core chronology (AICC2012): an optimized multi-parameter and multi-site dating approach for the last 120 thousand years. Clim. Past Discuss. 8, 6011–6049 (2012)

    ADS  Google Scholar 

  51. 51

    Veres, D. et al. The Antarctic ice core chronology (AICC2012): an optimized multi-parameter and multi-site dating approach for the last 120 thousand years. Clim. Past 9, 1733–1748 (2013)

    Google Scholar 

  52. 52

    Grobe, H. A simple method for the determination of ice-rafted debris in sediment cores. Polarforschung 57, 123–126 (1987)

    Google Scholar 

  53. 53

    Roy, M., van de Flierdt, T., Hemming, S. R. & Goldstein, S. L. 40Ar/39Ar ages of hornblende grains and bulk Sm/Nd isotopes of circum-Antarctic glacio-marine sediments: implications for sediment provenance in the southern ocean. Chem. Geol. 244, 507–519 (2007)

    CAS  ADS  Google Scholar 

  54. 54

    Pierce, E. L. et al. Characterizing the sediment provenance of East Antarctica’s weak underbelly: the Aurora and Wilkes sub-glacial basins. Paleoceanography 26, PA4217 (2011)

    ADS  Google Scholar 

  55. 55

    Galton-Fenzi, B. K., Hunter, J. R., Coleman, R., Marsland, S. J. & Warner, R. C. Modeling the basal melting and marine ice accretion of the Amery Ice Shelf. J. Geophys. Res. 117, C09031 (2012)

    ADS  Google Scholar 

  56. 56

    Anderson, J. B. & Andrews, J. T. Radiocarbon constraints on ice sheet advance and retreat in the Weddell Sea, Antarctica. Geology 27, 179–182 (1999)

    CAS  ADS  Google Scholar 

  57. 57

    Schodlok, M. P., Hellmer, H. H., Rohardt, G. & Fahrbach, E. Weddell Sea iceberg drift: five years of observations. J. Geophys. Res. 111, C06018 (2006)

    ADS  Google Scholar 

  58. 58

    Pudsey, C. J. & Howe, J. A. Quaternary history of the Antarctic Circumpolar Current: evidence from the Scotia Sea. Mar. Geol. 148, 83–112 (1998)

    ADS  Google Scholar 

  59. 59

    Jacka, T. H. & Giles, A. B. Antarctic iceberg distribution and dissolution from ship-based observations. J. Glaciol. 53, 341–356 (2007)

    ADS  Google Scholar 

  60. 60

    Williams, T. et al. Evidence for iceberg armadas from East Antarctica in the Southern Ocean during the late Miocene and early Pliocene. Earth Planet. Sci. Lett. 290, 351–361 (2010)

    CAS  ADS  Google Scholar 

  61. 61

    Toggweiler, J. R. & Russell, J. Ocean circulation in a warming climate. Nature 451, 286–288 (2008)

    CAS  ADS  PubMed  Google Scholar 

  62. 62

    Toggweiler, J. R. & Lea, D. W. Temperature differences between the hemispheres and ice age climate variability. Paleoceanography 25, PA2212 (2010)

    ADS  Google Scholar 

  63. 63

    Smith, J. A., Hillenbrand, C.-D., Pudsey, C. J., Allen, C. S. & Graham, A. G. C. The presence of polynyas in the Weddell Sea during the Last Glacial Period with implications for the reconstruction of sea-ice limits and ice sheet history. Earth Planet. Sci. Lett. 296, 287–298 (2010)

    CAS  ADS  Google Scholar 

  64. 64

    Nielsen, S. H. H., Hodell, D. A., Kamenov, G., Guilderson, T. & Perfit, M. R. Origin and significance of ice-rafted detritus in the Atlantic sector of the Southern Ocean. Geochem. Geophys. Geosyst. 8, 1–23 (2007)

    Google Scholar 

  65. 65

    Nakada, M. et al. Late Pleistocene and Holocene melting history of the Antarctic ice sheet derived from sea-level variations. Mar. Geol. 167, 85–103 (2000)

    ADS  Google Scholar 

  66. 66

    White, D. A., Fink, D. & Gore, D. B. Cosmogenic nuclide evidence for enhanced sensitivity of an East Antarctic ice stream to change during the last deglaciation. Geology 39, 23–26 (2011)

    CAS  ADS  Google Scholar 

  67. 67

    Kirshner, A. E. et al. Post-LGM deglaciation in Pine Island Bay, West Antarctica. Quat. Sci. Rev. 38, 11–26 (2012)

    ADS  Google Scholar 

  68. 68

    Hall, B. L. & Denton, G. H. Radiocarbon chronology of Ross Sea drift, Eastern Taylor Valley, Antarctica: evidence for a grounded ice sheet in the Ross Sea at the Last Glacial Maximum. Geogr. Ann. 82, 305–336 (2000)

    Google Scholar 

  69. 69

    Price, S. F., Conway, H. & Waddington, E. D. Evidence for late Pleistocene thinning of Siple Dome, West Antarctica. J. Geophys. Res. 112, F03021 (2007)

    ADS  Google Scholar 

  70. 70

    Simms, A. R., Milliken, K. T., Anderson, J. B. & Wellner, J. S. The marine record of deglaciation of the South Shetland Islands, Antarctica since the Last Glacial Maximum. Quat. Sci. Rev. 30, 1583–1601 (2011)

    ADS  Google Scholar 

  71. 71

    Leventer, A. et al. Marine sediment record from the East Antarctic margin reveals dynamics of ice sheet recession. Geol. Soc. Am. Today 16, 4–10 (2006)

    Google Scholar 

  72. 72

    McKay, R. M. et al. Retreat history of the Ross Ice Sheet (Shelf) since the Last Glacial Maximum from deep-basin sediment cores around Ross Island. Palaeogeogr. Palaeoclimatol. Palaeoecol. 260, 245–261 (2008)

    Google Scholar 

  73. 73

    Menviel, L. & Joos, F. Toward explaining the Holocene carbon dioxide and carbon isotope records: results from transient ocean carbon cycle-climate simulations. Paleoceanography 27, PA1207 (2012)

    ADS  Google Scholar 

  74. 74

    Ritz, S. P., Stocker, T. F. & Joos, F. A coupled dynamical ocean–energy balance atmosphere model for paleoclimate studies. J. Clim. 24, 349–375 (2011)

    ADS  Google Scholar 

  75. 75

    Menviel, L., Timmermann, A., Mouchet, A. & Timm, O. Climate and marine carbon cycle response to changes in the strength of the Southern Hemispheric westerlies. Paleoceanography 23, PA4201 (2008)

    ADS  Google Scholar 

  76. 76

    Timmermann, A., Timm, O., Stott, L. & Menviel, L. The roles of CO2 and orbital forcing in driving Southern Hemispheric temperature variations during the last 21 000 Yr. J. Clim. 22, 1626–1640 (2009)

    ADS  Google Scholar 

  77. 77

    Timm, O., Timmermann, A., Abe-Ouchi, A., Saito, F. & Segawa, T. On the definition of seasons in paleoclimate simulations with orbital forcing. Paleoceanography 23, PA2221 (2008)

    ADS  Google Scholar 

  78. 78

    Knorr, G., Butzin, M., Micheels, A. & Lohmann, G. A warm Miocene climate at low atmospheric CO2 levels. Geophys. Res. Lett. 38, L20701 (2011)

    ADS  Google Scholar 

  79. 79

    Zhang, X., Lohmann, G., Knorr, G. & Xu, X. Different ocean states and transient characteristics in Last Glacial Maximum simulations and implications for deglaciation. Clim. Past 9, 2319–2333 (2013)

    Google Scholar 

  80. 80

    Wei, W., Lohmann, G. & Dima, M. Distinct modes of internal variability in the global meridional overturning circulation associated with the Southern Hemisphere westerly winds. J. Phys. Oceanogr. 42, 785–801 (2012)

    ADS  Google Scholar 

  81. 81

    Lourantou, A. et al. Constraint of the CO2 rise by new atmospheric carbon isotopic measurements during the last deglaciation. Glob. Biogeochem. Cycles 24, GB2015 (2010)

    ADS  Google Scholar 

Download references


We acknowledge support from the Deutsche Forschungsgemeinschaft (DFG grant numbers We2039/7-1, Ri525/17-1 and Ku683/9-1 to M.E.W. and G.K.), the University of Cologne (to M.E.W.), the US NSF Antarctic Glaciology Program (grant numbers ANT-1043517 to P.U.C. and ANT-1341311 to A.T.), the US NSF Paleoclimatology Program and the Japan Agency for Marine-Earth Science and Technology (to A.T.), and Helmholtz funding through the Polar Regions and Coasts in the changing Earth System (PACES) programme (to X.Z., G.L. and G.K.). Our study was also part of the Southern Ocean Initiative of the International Marine Past Global Change Study (IMAGES) program. We thank W. F. Budd for comments on Antarctic ice-sheet dynamics, and M. Winstrup and S. Rasmussen for advice on comparing ice-core chronologies. Experiments with the Bern3D were performed in the Department of Climate and Environmental Physics, University of Bern, and with funding through the Oeschger Center for Climate Change.

Author information




M.E.W. conceived the idea for the study and, with P.U.C., wrote most of the manuscript. G.K. selected the core sites and provided geochemical data. A.T. oversaw the modelling contributions and helped write the manuscript. R.G. provided insight into iceberg routing and associated ice-sheet modelling. D.S. helped develop the age model and provided biogenic opal data. G.L. and X.Z. contributed results from the COSMOS model. L.M., M.O.C. and T.F. contributed results from Bern3D and LOVECLIM models. C.O. contributed uncertainty estimates on the different age models. All authors commented on the manuscript.

Corresponding author

Correspondence to M. E. Weber.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Additional information

Further data are available at

Extended data figures and tables

Extended Data Figure 1 Deglacial dust chronology.

Five common tie points (TP1 to TP5, indicated by green vertical bands) depict consistent changes in slope and reproducible lows and highs between magnetic susceptibility (a, b), Fe (c) and Ca (d) records of deep-sea sites MD07-31333 and MD07-313412, and the non-sea-salt Ca record (e) of the EDML ice core27.

Extended Data Figure 2 Uncertainty estimates for AIDs.

Conservative error estimates (2σ) rely on bootstrapping of different age models and projecting them on to AIDs. a, Errors of the MD age model12 based on tie point correlation only. Black dots depict the centre of the AID and its absolute uncertainty range. Black error bars at the boxes mark the relative uncertainty with respect to the centre. Grey error bars show the absolute uncertainty of the beginning and end of each AID. b, Errors including the EDML1 (ref. 47), and EDC3 (ref. 46) uncertainties. c, Relative duration of AIDs and related uncertainties. d, Error propagation of the three different age scales through the last deglaciation. IU is interpolation uncertainty. Note that uncertainties are highly correlated for nearby ages. Accounting for this correlation, the duration of each AID as well as the time between two AIDs is significantly more accurate than its absolute age uncertainty.

Extended Data Figure 3 X-radiograph images from Scotia Sea Site MD07-3134.

IBRD (bright dropstones) are embedded in a matrix-supported diatomaceous mud. Low IBRD contents are documented for the Last Glacial Maximum (LGM, 24.7 kyr ago) and the Holocene (8.8 kyr ago), whereas higher numbers indicate enhanced iceberg routeing through Iceberg Alley during three distinct deglaciation phases (centre panels): AID8 (MWP-19KA), AID7 and AID6 (MWP-1A).

Extended Data Table 1 Uncertainty estimates

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Weber, M., Clark, P., Kuhn, G. et al. Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation. Nature 510, 134–138 (2014).

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing