North Pacific freshwater events linked to changes in glacial ocean circulation


There is compelling evidence that episodic deposition of large volumes of freshwater into the oceans strongly influenced global ocean circulation and climate variability during glacial periods1,2. In the North Atlantic region, episodes of massive freshwater discharge to the North Atlantic Ocean were related to distinct cold periods known as Heinrich Stadials1,2,3. By contrast, the freshwater history of the North Pacific region remains unclear, giving rise to persistent debates about the existence and possible magnitude of climate links between the North Pacific and North Atlantic oceans during Heinrich Stadials4,5. Here we find that there was a strong connection between changes in North Atlantic circulation during Heinrich Stadials and injections of freshwater from the North American Cordilleran Ice Sheet to the northeastern North Pacific. Our record of diatom δ18O (a measure of the ratio of the stable oxygen isotopes 18O and 16O) over the past 50,000 years shows a decrease in surface seawater δ18O of two to three per thousand, corresponding to a decline in salinity of roughly two to four practical salinity units. This coincided with enhanced deposition of ice-rafted debris and a slight cooling of the sea surface in the northeastern North Pacific during Heinrich Stadials 1 and 4, but not during Heinrich Stadial 3. Furthermore, results from our isotope-enabled model6 suggest that warming of the eastern Equatorial Pacific during Heinrich Stadials was crucial for transmitting the North Atlantic signal to the northeastern North Pacific, where the associated subsurface warming resulted in a discernible freshwater discharge from the Cordilleran Ice Sheet during Heinrich Stadials 1 and 4. However, enhanced background cooling across the northern high latitudes during Heinrich Stadial 3—the coldest period in the past 50,000 years7—prevented subsurface warming of the northeastern North Pacific and thus increased freshwater discharge from the Cordilleran Ice Sheet. In combination, our results show that nonlinear ocean–atmosphere background interactions played a complex role in the dynamics linking the freshwater discharge responses of the North Atlantic and North Pacific during glacial periods.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Study area.
Fig. 2: Proxy data from the North Pacific and North Atlantic (50 kyr to 5 kyr bp).
Fig. 3: Results of freshwater hosing experiments LGM_NA, LGM_NA+NP and 30kyr_NA.
Fig. 4: Proxy data from the eastern Equatorial Pacific (EEP) and northeastern North Pacific (NENP).


  1. 1.

    Maslin, M. A., Shackleton, N. J. & Pflaumann, U. Surface water temperature, salinity, and density changes in the northeast Atlantic during the last 45,000 years: Heinrich events, deep water formation, and climatic rebounds. Paleoceanography 10, 527–544 (1995).

    Article  ADS  Google Scholar 

  2. 2.

    Kageyama, M. et al. Climatic impacts of fresh water hosing under Last Glacial Maximum conditions: a multi-model study. Clim. Past 9, 935–953 (2013).

    Article  Google Scholar 

  3. 3.

    Böhm, E. et al. Strong and deep Atlantic meridional overturning circulation during the last glacial cycle. Nature 517, 73–76 (2015).

    Article  PubMed  ADS  CAS  Google Scholar 

  4. 4.

    Praetorius, S. & Mix, A. Synchronisation of North Pacific and Greenland climates preceded abrupt deglacial warming. Science 345, 444–448 (2014).

    Article  PubMed  ADS  CAS  Google Scholar 

  5. 5.

    Menviel, L., England, M. H., Meissner, K. J., Mouchet, A. & Yu, J. Atlantic-Pacific seesaw and its role in outgassing CO2 during Heinrich events. Paleoceanography 29, 58–70 (2014).

    Article  ADS  Google Scholar 

  6. 6.

    Werner, M. et al. Glacial-interglacial changes in H2 18O, HDO and deuterium excess—results from the fully coupled ECHAM5/MPI-OM Earth system model. Geosci. Model Dev. 9, 647–670 (2016).

    Article  ADS  CAS  Google Scholar 

  7. 7.

    North Greenland Ice Core Project members. High-resolution record of Northern Hemisphere climate extending into the last interglacial period. Nature 431, 147–151 (2004).

    Article  CAS  Google Scholar 

  8. 8.

    Henry, L. G. et al. North Atlantic ocean circulation and abrupt climate changes during the last glaciation. Science 353, 470–474 (2016).

    Article  PubMed  ADS  CAS  Google Scholar 

  9. 9.

    Chikamoto, M. O. et al. Variability in North Pacific intermediate and deep water ventilation during Heinrich events in two coupled climate models. Deep Sea Res. Part II Top. Stud. Oceanogr. 61–64, 114–126 (2012).

    Article  ADS  Google Scholar 

  10. 10.

    Seguinot, J., Rogozhina, I., Stroeven, A. P., Margold, M. & Kleman, J. Numerical simulations of the Cordilleran ice sheet through the last glacial cycle. Cryosphere Discuss. 9, 4147–4203 (2015).

    Article  ADS  Google Scholar 

  11. 11.

    Hendy, I. L. & Cosma, T. Vulnerability of the Cordilleran Ice Sheet to iceberg calving during late Quaternary rapid climate change events. Paleoceanography 23, PA2101 (2008).

    Article  ADS  Google Scholar 

  12. 12.

    Maier, E. et al. Deglacial subarctic Pacific surface water hydrography and nutrient dynamics and links to North Atlantic climate variability and atmospheric CO2. Paleoceanography 30, 949–968 (2015).

    Article  ADS  Google Scholar 

  13. 13.

    Gebhardt, H. et al. Paleonutrient and productivity records from the subarctic North Pacific for Pleistocene glacial terminations I to V. Paleoceanography 23, PA4212 (2008).

    Article  ADS  Google Scholar 

  14. 14.

    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).

    Article  Google Scholar 

  15. 15.

    Siddall, M. et al. Sea-level fluctuations during the last glacial cycle. Nature 423, 853–858 (2003).

    Article  PubMed  ADS  CAS  Google Scholar 

  16. 16.

    Hu, A. et al. Influence of Bering Strait flow and North Atlantic circulation on glacial sea-level changes. Nat. Geosci. 3, 118–121 (2010).

    Article  ADS  CAS  Google Scholar 

  17. 17.

    Wiedmer, M., Montgomery, D. R., Gillespie, A. R. & Greenberg, H. Late Quaternary megafloods from Glacial Lake Atna, Couthcentral Alaska, U.S.A. Quat. Res. 73, 413–424 (2010).

    Article  Google Scholar 

  18. 18.

    Benito, G. & O’Connor, J. E. Number and size of last-glacial Missoula floods in the Columbia River valley between the Pasco Basin, Washington, and Portland, Oregon. Geol. Soc. Am. Bull. 115, 624–638 (2003).

    Article  ADS  Google Scholar 

  19. 19.

    Livingstone, S. J., Clark, C. D. & Tarasov, L. Modelling North American palaeo-subglacial lakes and their meltwater drainage pathways. Earth Planet. Sci. Lett. 375, 13–33 (2013).

    Article  ADS  CAS  Google Scholar 

  20. 20.

    Taylor, M. A., Hendy, I. L. & Pak, D. K. Deglacial ocean warming and marine margin retreat of the Cordilleran Ice Sheet. Earth Planet. Sci. Lett. 403, 89–98 (2014).

    Article  ADS  CAS  Google Scholar 

  21. 21.

    Praetorius, S. et al. North Pacific deglacial hypoxic events linked to abrupt climate warming. Nature 527, 362–366 (2015).

    Article  PubMed  ADS  CAS  Google Scholar 

  22. 22.

    Kipphut, G. W. Glacial meltwater input to the Alaska Coastal Current: evidence from oxygen isotope measurements. J. Geophys. Res. 95, 5177–5181 (1990).

    Article  ADS  CAS  Google Scholar 

  23. 23.

    Cheng, H. et al. Ice age terminations. Science 326, 248–252 (2009).

    Article  PubMed  ADS  CAS  Google Scholar 

  24. 24.

    Deplazes, G. et al. Links between tropical rainfall and North Atlantic climate during the last glacial period. Nat. Geosci. 6, 213–217 (2013).

    Article  ADS  CAS  Google Scholar 

  25. 25.

    Martínez-Botí, M. A. et al. Boron isotope evidence for oceanic carbon dioxide leakage during the last deglaciation. Nature 518, 219–222 (2015).

    Article  PubMed  ADS  CAS  Google Scholar 

  26. 26.

    Leduc, G. et al. Moisture transport across Central America as a positive feedback on abrupt climatic changes. Nature 445, 908–911 (2007).

    Article  PubMed  ADS  CAS  Google Scholar 

  27. 27.

    Okumura, Y. M., Deser, C., Hu, A., Timmermann, A. & Xie, S.-P. North Pacific climate response to freshwater forcing in the subarctic North Atlantic: oceanic and atmospheric pathways. J. Clim. 22, 1424–1445 (2009).

    Article  ADS  Google Scholar 

  28. 28.

    Marcott, S. A. et al. Ice-shelf collapse from subsurface warming as a trigger for Heinrich Events. Proc. Natl Acad. Sci. USA 108, 13415–13419 (2011).

    Article  PubMed  ADS  Google Scholar 

  29. 29.

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

    Article  PubMed  ADS  CAS  Google Scholar 

  30. 30.

    Antonov, J. I. et al. World Ocean Atlas 2009, Vol. 2: Salinity. (NOAA Atlas NESDIS 69, US Gov. Print. Off., Washington DC, 2010).

    Google Scholar 

  31. 31.

    Ruth, U. et al. Ice core evidence for a very tight link between North Atlantic and east Asian glacial climate. Geophys. Res. Lett. 34, L03706 (2007).

    Article  ADS  Google Scholar 

  32. 32.

    Serno, S. et al. Comparing dust flux records from the Subarctic North Pacific and Greenland: implications for atmospheric transport to Greenland and for application of dust as a chronostratigraphic tool. Paleoceanography 30, 583–600 (2015).

    Article  ADS  Google Scholar 

  33. 33.

    Hendy, I. L., Kennett, J. P., Roark, E. B. & Ingram, B. L. Apparent synchroneity of submillennial scale climate events between Greenland and Santa Barbara Basin, California from 30-10 ka. Quat. Sci. Rev. 21, 1167–1184 (2002).

    Article  ADS  Google Scholar 

  34. 34.

    Cartapanis, O., Tachikawa, K. & Bard, E. Northeastern Pacific oxygen minimum zone variability over the past 70 kyr: impact of biological production and oceanic ventilation. Paleoceanography 26, PA4208 (2011).

    Article  ADS  Google Scholar 

  35. 35.

    Blaauw, M. & Christen, A. J. Flexible paleoclimate age-depth models using an autoregressive gamma process. Bayesian Anal. 6, 457–474 (2011).

    MathSciNet  MATH  Google Scholar 

  36. 36.

    Reimer, P. J. et al. INTCAL13 and MARINE13 radiocarbon age calibration curves 0-50,000 years cal BP. Radiocarbon 55, 1869–1887 (2013).

    Article  CAS  Google Scholar 

  37. 37.

    Sarnthein, M., Balmer, S., Grootes, P. M. & Muddelsee, M. Planktic and benthic 14C reservoir ages for three ocean basins calibrated by a suite of 14C plateaus in the glacial-to-deglacial Suigetsu atmospheric 14C record. Radiocarbon 57, 129–151 (2015).

    Article  CAS  Google Scholar 

  38. 38.

    Maier, E. et al. Combined oxygen and silicon isotope analysis of diatom silica from a deglacial subarctic Pacific record. J. Quat. Sci. 28, 571–581 (2013).

    Article  Google Scholar 

  39. 39.

    Sancetta, C. Distribution of diatom species in surface sediments of the Bering and Okhotsk seas. Micropaleontology 28, 221–257 (1982).

    Article  Google Scholar 

  40. 40.

    Sancetta, C. Three species of Coscinodiscus Ehrenberg from North Pacific sediments examined in the light and scanning electron microscopes. Micropaleontology 33, 230–241 (1987).

    Article  Google Scholar 

  41. 41.

    Swann, G. E. A. & Leng, M. J. A review of diatom δ18O in palaeoceanography. Quat. Sci. Rev. 28, 384–398 (2009).

    Article  ADS  Google Scholar 

  42. 42.

    Taylor, H. P. J. The oxygen isotope geochemistry of igneous rocks. Contrib. Mineral. Petrol. 19, 1–71 (1968).

    Article  ADS  CAS  Google Scholar 

  43. 43.

    Sheppard, A. M. F. & Gilg, H. A. Stable isotope geochemistry of clay minerals. Clay Miner. 31, 1–24 (1996).

    Article  ADS  CAS  Google Scholar 

  44. 44.

    Chapligin, B. et al. A high-performance, safer and semi-automated approach for the analysis of diatom silica and new methods for removing exchangeable oxygen. Rapid Commun. Mass Spectrom. 24, 2655–2664 (2010).

    Article  PubMed  ADS  CAS  Google Scholar 

  45. 45.

    Chapligin, B. et al. Inter-laboratory comparison of oxygen isotope compositions from biogenic silica. Geochim. Cosmochim. Acta 75, 7242–7256 (2011).

    Article  ADS  CAS  Google Scholar 

  46. 46.

    Von Huene, R., Larson, E. & Crouch, J. in Initial Reports of the Deep Sea Drilling Project, Vol. XVIII (eds Musich, L. F. & Weser, O. E.) 835–842 (US Gov. Printing Office, Washington DC, 1973).

  47. 47.

    St John, K. E. K. & Krissek, L. A. Regional patterns of Pleistocene ice-rafted debris flux in the North Pacific. Paleoceanography 14, 653–662 (1999).

    Article  ADS  Google Scholar 

  48. 48.

    Méheust, M., Fahl, K. & Stein, R. Variability in modern sea surface temperature, sea ice and terrigenous input in the sub-polar North Pacific and Bering Sea: reconstruction from biomarker data. Org. Geochem. 57, 54–64 (2013).

    Article  CAS  Google Scholar 

  49. 49.

    Sikes, E. L., Volkman, J. K., Robertson, L. G. & Pichon, J.-J. Alkenones and alkenes in surface waters and sediments of the Southern Ocean: implications for paleotemperature estimation in polar regions. Geochim. Cosmochim. Acta 61, 1495–1505 (1997).

    Article  ADS  CAS  Google Scholar 

  50. 50.

    Leclerc, A. J. & Labeyrie, L. Temperature dependence of the oxygen isotopic fractionation between diatom silica and water. Earth Planet. Sci. Lett. 84, 69–74 (1987).

    Article  ADS  CAS  Google Scholar 

  51. 51.

    Waelbroeck, C. et al. Sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. Quat. Sci. Rev. 21, 295–305 (2002).

    Article  ADS  Google Scholar 

  52. 52.

    Takahashi, K. Seasonal fluxes of pelagic diatoms in the subarctic Pacific, 1982–1983. Deep-Sea Res. 33, 1225–1251 (1986).

    Article  ADS  Google Scholar 

  53. 53.

    Epstein, S. & Sharp, R. P. Oxygen-isotope variations in the Malaspina and Saskatchewan glaciers. J. Geol. 67, 88–102 (1959).

    Article  ADS  CAS  Google Scholar 

  54. 54.

    Dansgaard, W. & Tauber, H. Glacier oxygen-18 content and Pleistocene ocean temperatures. Science 166, 499–502 (1969).

    Article  PubMed  ADS  CAS  Google Scholar 

  55. 55.

    IAEA/WMO. Global Network of Isotopes in Precipitation. The GNIP Database (2015).

  56. 56.

    Jakobsson, M. et al. Post-glacial flooding of the Bering Land Bridge dated to 11calka BP based on new geophysical and sediment records. Clim. Past 13, 991–1005 (2017).

    Article  Google Scholar 

  57. 57.

    Roeckner, E. et al. The Atmospheric General Circulation Model ECHAM5. Part 1: Model Description (Max Planck Inst. Meteorol. Rep. 349, 2003).

  58. 58.

    Brovkin, V., Raddatz, T., Reick, C. H., Claussen, M. & Gaylor, V. Global biogeophysical interactions between forest and climate. Geophys. Res. Lett. 36, L07405 (2009).

    Article  Google Scholar 

  59. 59.

    Marsland, S. J., Haak, H., Jungclaus, J. H., Latif, M. & Röske, F. The Max-Planck-Institute global ocean/sea ice model with orthogonal curvilinear coordinates. Ocean Model. 5, 91–127 (2003).

    Article  ADS  Google Scholar 

  60. 60.

    Hibler, W. III A dynamic thermodynamic sea ice model. J. Phys. Oceanogr. 9, 815–846 (1979).

    Article  ADS  Google Scholar 

  61. 61.

    Zhang, X., Lohmann, G., Knorr, G. & Purcell, C. Abrupt glacial climate shifts controlled by ice sheet changes. Nature 512, 290–294 (2014).

    Article  PubMed  ADS  CAS  Google Scholar 

  62. 62.

    Zhang, X., Knorr, G., Lohmann, G. & Barker, S. Abrupt North Atlantic circulation changes in response to gradual CO2 forcing in a glacial climate state. Nat. Geosci. 10, 518–523 (2017).

    Article  ADS  CAS  Google Scholar 

  63. 63.

    Monterey, G. & Levitus, S. Seasonal Variability of Mixed Layer Depth for the World Ocean (NOAA Atlas NESDIS 14, US Gov. Printing Office, Washington DC, 1997).

    Google Scholar 

  64. 64.

    Kuroyanagi, A., Kawahata, H. & Nishi, H. Seasonal variation in the oxygen isotopic composition of different-sized planktonic foraminifer Neogloboquadrina pachyderma (sinistral) in the northwestern North Pacific and implications for reconstruction of the paleoenvironment. Paleoceanography 26, PA4215 (2011).

    Article  ADS  Google Scholar 

  65. 65.

    Mulitza, S. et al. Temperature: δ18O relationships of planktonic foraminifera collected from surface waters. Palaeogeogr. Palaeoclimatol. Palaeoecol. 202, 143–152 (2003).

    Article  Google Scholar 

  66. 66.

    Zhang, Y. et al. Equatorial Pacific forcing of western Amazonian precipitation during Heinrich Stadial 1. Sci. Rep. 6, 35866 (2016).

    Article  PubMed  PubMed Central  ADS  CAS  Google Scholar 

  67. 67.

    Lambeck, K. & Chappell, J. Sea level change through the last glacial cycle. Science 292, 679–686 (2001).

    Article  PubMed  ADS  CAS  Google Scholar 

  68. 68.

    Grant, K. M. et al. Rapid cooling between ice volume and polar temperature over the past 150,000 years. Nature 491, 744–747 (2012).

    Article  PubMed  ADS  CAS  Google Scholar 

  69. 69.

    Köhler, P., Nehrbass-Ahles, C., Schmitt, J., Stocker, T. F. & Fischer, H. A. 156 kyr smoothed history of the atmospheric greenhouse gases CO2, CH4, and N2O and their radiative forcing. Earth Syst. Sci. Data 9, 363–387 (2017).

    Article  ADS  Google Scholar 

  70. 70.

    Berger, A. L. Long-term variations of caloric insolation resulting from the Earth’s orbital elements. Quat. Res. 9, 139–167 (1978).

    Article  Google Scholar 

  71. 71.

    Flückinger, J., Knutti, R. & White, J. W. C. Oceanic processes as potential trigger and amplifying mechanisms for Heinrich events. Paleoceanography 21, PA2014 (2006).

    ADS  Google Scholar 

  72. 72.

    Álvarez-Solas, J. et al. Heinrich event 1: an example of dynamic ice-sheet reaction to oceanic changes. Clim. Past 7, 1297–1306 (2011).

    Article  Google Scholar 

  73. 73.

    Bronk Ramsey, C. et al. A complete terrestrial radiocarbon record for 11.2 to 52.8 kyr B.P. Science 338, 370–374 (2012).

    Article  PubMed  ADS  CAS  Google Scholar 

  74. 74.

    Gersonde, R. Documentation of sediment core SO202-27-6 (2010).

  75. 75.

    Laskar, J. et al. A long-term numerical solution for the insolation quantities of the Earth. Astron. Astrophys. 428, 261–285 (2004).

    Article  ADS  Google Scholar 

  76. 76.

    Clague, J. J. & James, T. S. History and isostatic effects of the last ice sheet in southern British Columbia. Quat. Sci. Rev. 21, 71–87 (2002).

    Article  ADS  Google Scholar 

  77. 77.

    Kaufman, D. S., Young, N. E., Briner, J. P. & Manley, W. F. Alaska palaeo-glacier atlas (version 2). Dev. Quat. Sci. 15, 427–445 (2011).

    Google Scholar 

  78. 78.

    Ehlers, J. & Gibbard, P. L. The extent and chronology of Cenozoic global glaciation. Quat. Int. 164-165, 6–20 (2007).

    Article  Google Scholar 

  79. 79.

    Schlitzer, R. Ocean Data View (2018).

Download references


This work was largely part of the Innovative NOrth Pacific EXperiment (INOPEX), funded by the Bundesministerium für Bildung und Forschung. We also acknowledge funding by the Helmholtz Postdoc program (PD-301; to X.Z.), as well as Helmholtz funding through the Polar Regions and Coasts in the Changing Earth System (PACES) program of the Alfred Wegener Institute. Funding from the Qingdao National Laboratory for Marine Science and Technology (QNLM201703) is also acknowledged. We thank U. Böttjer, B. Glückselig and R. Cordelair for the thorough purification of diatom samples for isotope analyses; M. Warnkross for picking planktic foraminifera for stable-isotope analysis and radiocarbon dating; S. Steph and A. Mackensen for performing the foraminiferal oxygen-isotope analysis; and G. Knorr for helpful discussions.

Reviewer information

Nature thanks S. Dee, A. Hu, K. Thirumalai and the other anonymous reviewer(s) for their contribution to the peer review of this work.

Author information




E.M. and X.Z. designed the study and wrote the manuscript with contributions from A.A., R.G. and G.L. E.M. performed the diatom isotope measurements with support from B.C. and H.M. X.Z. designed the model experiments and performed simulations with support from M.W. and G.L. E.M. constructed the age model and S.M. carried out the proxy uncertainty modelling. E.M. performed the contamination analysis of diatom samples. M.M. and R.S. contributed alkenone-based sea-surface temperatures (SSTs), and J.R. the diatom composition of the isotope samples. All authors contributed to the final version of the manuscript.

Corresponding authors

Correspondence to E. Maier or X. Zhang.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data figures and tables

Extended Data Fig. 1 Results from two freshwater hosing experiments.

Left, LGM_NA; right LGM_NA+NP. Model results are presented as anomalies between the hosing simulations and the LGM state (see Methods). a, e, Total precipitation anomalies. b, f, Precipitation δ18O anomalies. c, g, δ18Odiat. anomalies. d, h, Subsurface δ18Osw anomalies (at depths of 120–180 m). The yellow star marks the location of core SO202-27-6.

Extended Data Fig. 2 Link between our data from core SO202-27-6, and NGRIP climate variabilities.

a–d, SO202-27-6. a, Scheme and pictures describing the sediment core74. b, Linear sedimentation rate (LSR). c, Calcium intensity based on XRF analysis. d, Iron intensity based on XRF analysis. ka, thousands of years ago; kcps, thousands of counts per second. e, NGRIP δ18O record7. f, NGRIP dust concentration31, including age-control points for SO202-27-6. g, Mean summer insolation at 65° N (ref. 75).

Extended Data Fig. 3 SSS/δ18Osw mixing model for the last glacial open northeastern North Pacific.

a, Study area as shown in Fig. 1, including the modern extent of the CIS (black), the extent of the CIS during the LGM76,77 (black dashed line), the site of the studied core (yellow star), and the locations where precipitation (red dots) and modern glacier (light blue dots) parameters were taken for the SSS/δ18Osw mixing model. b, Study area from the North Pacific. Shaded white areas represent the extents of the LIS and CIS during the LGM78. c, SSS/δ18Osw mixing model assuming linear regression between SSS and δ18Osw. We used three low-salinity endmembers and one high-salinity endmember to estimate SSS changes at our core site between 43 kyr and 11 kyr ago (see Methods). The Northern Hemisphere map and the SSS map were created using Ocean Data View79.

Extended Data Fig. 4 Sea-level-pressure and surface-wind anomalies in our hosing experiments.

a, b, Results obtained using COSMOS. a, LGM_NA experiment. b, 30kyr_NA experiment. c–f, Results obtained using ECHAM5. c, A_HS1 experiment. d–f, A_HS1 experiment, imposing SST fields on the Atlantic Basin (Atl) only (d), the Atlantic Basin and the east Equatorial Pacific (EEP; e), and the EEP only (f). The yellow star marks the location of studied Core SO202-27-6. Surface-wind anomalies (vectors) are presented in m s−1. Sea-level-pressure anomalies are shown with shading.

Extended Data Fig. 5 Results from freshwater hosing experiments LGM_NP, LGM_NA and LGM_NA02, presented as anomalies.

a–c, LGM_NP experiment (0.1 Sv). a, Global SST anomaly; b, North Pacific subsurface temperature anomaly (120–180 m). c, Temperature anomaly over the meridional transaction of the Atlantic basin (60° W to 15° W). d–g, LGM_NA experiment (0.15 Sv) (d, e) and LGM_NA02 experiment (0.2 Sv) (f, g). d, f, AMOC field anomalies. e, g, Subsurface temperature anomalies (120–180 m). The yellow star marks the location of core SO202-27-6.

Extended Data Fig. 6 Comparison of northwestern North Pacific eolian dust and iron intensity, as well as NGRIP dust concentration over the last deglaciation.

a, Eolian dust (terrestrial 4He concentration)32 and b, iron intensity from core SO202-07-6 (51.3° N, 167.7° E; 2,340 m water depth). c, NGRIP dust concentration31. Dust changes in the northwestern North Pacific and Greenland are synchronous32, and coincide with iron-intensity changes in the northwestern North Pacific. B/A, Bølling/Allerød interstadial; YD, Younger Dryas cold period. Red arrows mark chronological coincidence between the changes in 4He, iron intensity and NGRIP dust concentration; ncc STP g−1, nano-cubic centimetre per gram at standard temperature and pressure.

Extended Data Fig. 7 Age–depth relationship for core SO202-27-6.

The grey envelope shows the 95% confidence interval around the median age (black line). Crosses indicate age-control points obtained from radiocarbon dating (red), and from proxy correlation to core MD02-2489 (ref. 12) and the NGRIP dust record31 (blue).

Extended Data Fig. 8 Diatom isotope sample composition, residual contamination with non-biogenic silicates and mass-balance-corrected δ18Odiat. (from core SO202-27-6).

a, Relative abundances of the following diatom species in the isotope samples: C. marginatus, C. oculus-iridis, and other diatom species. b, Contamination of purified diatom samples with non-biogenic silicates, estimated by inductively coupled plasma optical emission spectrometry (ICP-OES) and energy-dispersive X-ray spectrometry (EDS). c, Blue line, measured δ18Odiat. values (error bars indicate errors of replicate analyses or long-term reproducibility of standards (1σ)). Black dotted lines, δ18Odiat. values that have been mass-balance-corrected for contamination with non-biogenic silicates (estimated by EDS), and using one of two different δ18O values for non-biogenic silicate contamination (+2‰ or +30‰). Contamination values, δ18Odiat. values and mass-balance-corrected δ18Odiat. values younger than 25 kyr bp are taken from ref. 12.

Extended Data Table 1 Overview of model experiments
Extended Data Table 2 Age constraints of core SO202-27-6

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Maier, E., Zhang, X., Abelmann, A. et al. North Pacific freshwater events linked to changes in glacial ocean circulation. Nature 559, 241–245 (2018).

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.