Climate of the Past www.clim-past.net 1814-9324 1814-9332 5 1 2009 10.5194/cp-5-53-2009 http://www.clim-past.net/5/53/2009/ http://www.clim-past.net/5/53/2009/cp-5-53-2009.html http://www.clim-past.net/5/53/2009/cp-5-53-2009.pdf 53 72 2009-03-06 Millennial-scale climatic variability between 340 000 and 270 000 years ago in SW Europe: evidence from a NW Iberian margin pollen sequence S. Desprat sdesprat@whoi.edu M. F. Sánchez Goñi J. F. McManus J. Duprat E. Cortijo EPHE, UMR-CNRS 5805, EPOC, Université Bordeaux 1, Avenue des Facultés, 33405 Talence, France Woods Hole Oceanographic Institution, Department of Geology and Geophysics, Woods Hole, MA 02543, USA Laboratoire des Sciences du Climat et de l'Environnement, LSCE-Vallée, Bât. 12, avenue de la Terrasse, 91198 Gif-Sur-Yvette cedex, France We present a new high-resolution marine pollen record from NW Iberian margin sediments (core MD03-2697) covering the interval between 340 000 and 270 000 years ago, a time period centred on Marine Isotope Stage (MIS) 9 and characterized by particular baseline climate states. This study enables the documentation of vegetation changes in the north-western Iberian Peninsula and therefore the terrestrial climatic variability at orbital and in particular at millennial scales during MIS 9, directly on a marine stratigraphy. Suborbital vegetation changes in NW Iberia in response to cool/cold events are detected throughout the studied interval even during MIS 9e ice volume minimum. However, they appear more frequent and of higher amplitude during the 30 000 years following the MIS 9e interglacial period and during the MIS 9a-8 transition, which correspond to intervals of an intermediate to high ice volume and mainly periods of ice growth. Each suborbital cold event detected in NW Iberia has a counterpart in the Southern Iberian margin SST record. High to moderate amplitude cold episodes detected on land and in the ocean appear to be related to changes in deep water circulation and probably to iceberg discharges at least during MIS 9d, the mid-MIS 9c cold event and MIS 9b. This work provides therefore additional evidence of pervasive millennial-scale climatic variability in the North Atlantic borderlands throughout past climatic cycles of the Late Pleistocene, regardless of glacial state. However, ice volume might have an indirect influence on the amplitude of the millennial climatic changes in Southern Europe. % vor jede Referenz Alcara Ariza, F., Asensi Marfil, A., de Bolos, O., Capdevilla, O., Costa Tales, M., Arco Aguilar, M., Diaz Gonzales, T. E., Diez Garretas, B., Fernandez Prieto, J. A., Fernandez Gonzales, F., Izco Sevillando, J., Loidi Arregui, J., Martinez Parras, J. M., Navarro Andres, F., Ninot I Sugranes, J. M., Peinado Lorca, M., Rivas Martinez, S., Sanchez Mata, D., Valle Guitierrez, C., Vigo I., Bonada, J., and Wildpret de la Torre, W.: La vegetación de España, Universidad de Alcala de Henares, Spain, 544~pp., 1987. Allen, J. R. M., Brandt, U., Brauer, A., Hubberten, H.-W., Huntley, B., Keller, J., Kraml, M., Mackensen, A., Mingram, J., Negendank, J. F. W., Nowaczyk, N. R., Oberhänsli, H., Watts, W. A., Wulf, S., and Zolitschka, B.: Rapid environmental changes in southern Europe during the last glacial period, Nature, 400, 740–743, doi:10.1038/23432, 1999. Atlas Nacional de España: Climatologia, Ministerio de Obras Publicas y Transportes, Direccion General del Instituto Geografico Nacional, Madrid, Spain, 1992. Berger, A. L.: Long-Term variations of daily insolation and Quaternary climatic changes, J. Atmos. Sci., 35, 2362–2367, 1978. Bintanja, R., van de Wal, R. S. W., and Oerlemans, J.: Modelled atmospheric temperatures and global sea levels over the past million years, Nature, 437, 125–128, doi:10.1038/nature03975, 2005. Bond, G., Broecker, W., Johnsen, S., McManus, J., Labeyrie, L., Jouzel, J., and Bonani, G.: Correlations between climate records from North Atlantic sediments and Greenland ice, Nature, 365, 143–147, doi:10.1038/365143a0, 1993. Bond, G., Kromer, B., Beer, J., Muscheler, R., Evans, M. N., Showers, W., Hoffman, S., Lotti-Bond, R., Hajdas, I., and Bonani, G.: Persistent solar influence on North Atlantic climate during the Holocene, Science, 294, 2130–2136, doi:10.1126/science.1065680, 2001. Bond, G. and Lotti, R.: Iceberg discharges into the North Atlantic on millennial time scales during the Last Glaciation, Science, 267, 1005–1009, doi:10.1126/science.267.5200.1005, 1995. Bond, G., Showers, W., Cheseby, M., Lotti, R., Almasi, P., deMenocal, P., Priore, P., Cullen, H., Hajdas, I., and Bonani, G.: A pervasive millennial-scale cycle in North Atlantic Holocene and Glacial Climates, Science, 278, 1257–1266, doi:10.1126/science.278.5341.1257, 1997. Broecker, W. S., Bond, G., Klas, M., Bonani, G., and Wolfli, W.: A salt oscillator in the glacial Atlantic?, 1. The concept, Paleoceanography, 5, 469–477, 1990. Came, R. E., Oppo, D. W., and McManus, J. F.: Amplitude and timing of temperature and salinity variability in the subpolar North Atlantic over the past 10 k.y, Geology, 35, 315–318, 2007. Chapman, M. R. and Shackelton, N. J.: Global ice-volume fluctuations, North Atlantic ice-rafted events, and deep-ocean circulation changes between 130 and 70 ka, Geology, 27, 795–798, 1999. Cortijo, E., Duplessy, J.-C., Labeyrie, L., Leclaire, H., Duprat, J., and van Weering, T. C. E.: Eemian cooling in the Norwegian Sea and North Atlantic Ocean preceding continental ice-sheet growth, Nature, 372, 446–449, doi:10.1038/372446a0, 1994. Crucifix, M. and Loutre, M. F.: Transient simulations over the last interglacial period (126–115 kyr BP): feedback and forcing analysis, Clim. Dynam., 19, 417–433, 2002. Dansgaard, W., Johnsen, S. J., Clausen, H. B., Dahl-Jensen, D., Gundestrup, N. S., Hammer, C. U., Hvidberg, C. S., Steffensen, J. P., Sveinbjörnsdottir, A. E., Jouzel, J., and Bond, G.: Evidence for general instability of past climate from a 250-kyr ice-core record, Nature, 364, 218–220, doi:10.1038/364218a0, 1993. de Vernal, A., Henry, M., and Bilodeau, G.: Techniques de préparation et d'analyse en micropaléontologie, Les cahiers du GEOTOP, 3, 16–27, 1996. Delmotte, M., Chappellaz, J., Brook, E., Yiou, P., Barnola, J. M., Goujon, C., Raynaud, D., and Lipenkov, V. I.: Atmospheric methane during the last four glacial-interglacial cycles: Rapid changes and their link with Antarctic temperature, J. Geophys. Res., 109, D12104, doi:10.1029/2003JD004417, 2004. Desprat, S.: Réponses climatiques marines et continentales du Sud-Ouest de l'Europe lors des derniers interglaciaires et des entrées en glaciations, PhD thesis, Université Bordeaux I, France, 282~pp., 2005. Desprat, S., Sanchez Goni, M. F., Naughton, F., Turon, J.-L., Duprat, J., Malaize, B., Cortijo, E., and Peypouquet, J.-P.: Climate variability of the last five isotopic interglacials: Direct land-sea-ice correlation from the multiproxy analysis of North-Western Iberian margin deep-sea cores, in: The Climate of Past Interglacials, Developments in Quaternary Science, edited by: Sirocko, F., Litt, T., Claussen, M., and Sánchez Goñi, M. F., Elsevier, 375–386, 2007. Desprat, S., Sánchez Goñi, M. F., Turon, J.-L., Duprat, J., Malaizé, B., and Peypouquet, J.-P.: Climatic variability of Marine Isotope Stage 7: direct land-sea-ice correlation from a multiproxy analysis of a northwestern Iberian margin deep-sea core, Quaternary Sci. Rev., 25, 1010–1026, 2006. Desprat, S., Sánchez Goñi, M. F., Turon, J.-L., McManus, J. F., Loutre, M. F., Duprat, J., Malaizé, B., Peyron, O., and Peypouquet, J.-P.: Is vegetation responsible for glacial inception during periods of muted insolation changes?, Quaternary Sci. Rev, 24, 1361–1374, 2005. EPICA community members: Eight glacial cycles from an Antarctic ice core, Nature, 429, 623–628, doi:10.1038/nature02599, 2004. Fronval, T. and Jansen, E.: Eemian and early Weichselian (140–60 ka) paleoceanography and paleoclimate in the Nordic seas with comparisons to Holocene conditions, Paleoceanography, 12, 443–462, 1997. Grimm, E. C., Watts, W. A., Jacobson Jr., G. L., Hansen, B. C. S., Almquist, H., and Dieffenbacher-Krall, A. C.: Warm Wet Heinrich Events in Florida, Quaternary Sci. Rev., 25, 2197–2211, 2006. Grootes, P. M., Stuiver, M., White, J. W. C., Johnsen, S., and Jouzel, J.: Comparison of oxygen isotope records from the GISP2 and GRIP Greenland ice cores, Nature, 366, 552–554, doi:10.1038/366552a0, 1993. Heusser, L. E. and Balsam, W. L.: Pollen distribution in the N. E. Pacific Ocean, Quaternary Res., 7, 45–62, 1977. Heusser, L. and Oppo, D.: Millennial- and orbital-scale climate variability in southeastern United States and in the subtropical Atlantic during Marine Isotope Stage 5: evidence from pollen and isotopes in ODP Site 1059, Earth Planet. Sc. Lett., 214, 483–490, 2003. Huber, C., Leuenberger, M., Spahni, R., Flückiger, J., Schwander, J., Stocker, T. F., Johnsen, S., Landais, A., and Jouzel, J.: Isotope calibrated Greenland temperature record over Marine Isotope Stage 3 and its relation to CH4, Earth Planet. Sc. Lett., 243, 504–519, 2006. Indermühle, A., Monnin, E., Stauffer, B., Stocker, T. F., and Wahlen, M.: Atmospheric CO₂ concentration from 60 to 20 kyr BP from the Taylor Dome Ice Core, Antarctica, Geophys. Res. Lett., 27, 735–738, 2000. Kageyama, M., Charbit, S., Ritz, C., Khodri, M., and Ramstein, G.: Quantifying ice-sheet feedbacks during the last glacial inception, Geophys. Res. Lett., 31, L24203, doi:10.1029/2004GL021339, 2004. Kandiano, E. S. and Bauch, H. A.: Surface ocean temperatures in the Northeast Atlantic during the last 500 000 years: Evidence from foraminiferal census data, Terra Nova, 4, 265–271, doi:10.1046/j.1365-3121.2003.00488.x, 2003. Kawamura, K., Parrenin, F., Lisiecki, L., Uemura, R., Vimeux, F., Severinghaus, J. P., Hutterli, M. A., Nakazawa, T., Aoki, S., Jouzel, J., Raymo, M. E., Matsumoto, K., Nakata, H., Motoyama, H., Fujita, S., Goto-Azuma, K., Fujii, Y., and Watanabe, O.: Northern Hemisphere forcing of climatic cycles in Antarctica over the past 360000 years, Nature, 448, 912–916, doi:10.1038/nature06015, 2007. Kukla, G., McManus, J. F., Rousseau, D.-D., and Chuine, I.: How long and how stable was the last interglacial?, Quaternary Rev., 16, 605–612, 1997. Lea, D. W., Pak, D. K., Peterson, L. C., and Hughen, K. A.: Synchroneity of tropical high latitude Atlantic temperatures over the last glacial termination, Science, 301, 1361–1364, doi:10.1126/science.1088470, 2003. Lea, D. W., Pak, D. K., and Spero, H. J.: Climate impact of the Late Quaternary Equatorial Pacific sea surface temperature variations, Science, 289, 1719–1724, doi:10.1126/science.289.5485.1719, 2000. Lehman, S. J., Sachs, J. P., Crotwell, A. M., Keigwin, L. D., and Boyle, E. A.: Relation of subtropical Atlantic temperature, high-latitude ice rafting, deep water formation, and European climate 130000–60000 years ago, Quaternary Sci. Rev., 21, 1917–1924, 2002. Martrat, B., Grimalt, J. O., Lopez-Martinez, C., Cacho, I., Sierro, F. J., Flores, J. A., Zahn, R., Canals, M., Curtis, J. H., and Hodell, D. A.: Abrupt temperature changes in the Western Mediterranean over the past 250000 years, Science, 306, 1762–1765, doi:10.1126/science.1101706, 2004. Martrat, B., Grimalt, J. O., Shackleton, N. J., de Abreu, L., Hutterli, M. A., and Stocker, T. F.: Four climate cycles of recurring deep and surface water destabilizations on the Iberian margin, Science, 317, 502–507, doi:10.1126/science.1139994, 2007. Mayewski, P. A., Meeker, L. D., Twickler, M. S., Whitlow, S. I., Yang, Q., Lyons, W. B., and Prentice, M.: Major features and forcing of high latitude northern hemisphere atmospheric circulation over the last 110000 years, J. Geophys. Res., 102, 26345–26366, 1997. McManus, J. F., Bond, G. C., Broecker, W. S., Johnsen, S., Labeyrie, L., and Higgins, S.: High-resolution climate records from the North Atlantic during the last interglacial, Nature, 371, 326–329, 1994. McManus, J. F., Francois, R., Gherardi, J.-M., Keigwin, L. D., and Brown-Leger, S.: Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes, Nature, 428, 834–837, doi:10.1038/nature02494, 2004. McManus, J. F., Oppo, D. W., and Cullen, J. L.: A 0.5-million-year record of millennial-scale climate variability in the North Atlantic, Science, 283, 971–975, doi:10.1126/science.283.5404.971, 1999. McManus, J. F., Oppo, D. W., and Cullen, J. L.: ODP 980 Isotope and IRD Data. IGBP PAGES/World Data Center A for Paleoclimatology, Data Contribution Series #2001-065. NOAA/NGDC Paleoclimatology Program, Boulder, CO, USA, 2001. McManus, J. F., Oppo, D. W., and Keigwin, L. D.: Thermohaline circulation and prolonged interglacial warmth in the North Atlantic, Quaternary Res., 58, 17–21, 2002. Naughton, F.: As variações climáticas dos \'ultimos 30000 anos e sua influência na evolução dos sistemas costeiros do norte de Portugal, PhD thesis, University of Lisbon, Portugal, 362~pp., 2007. Naughton, F., Sanchez Goni, M. F., Desprat, S., Turon, J.-L., Duprat, J., Malaize, B., Joli, C., Cortijo, E., Drago, T., and Freitas, M. C.: Present-day and past (last 25000 years) marine pollen signal off western Iberia, Mar. Micropaleontol., 62, 91–114, 2007. Oppo, D. W.: Millennial climate oscillations, Science, 278, 1244–1246, doi:10.1126/science.278.5341.1244, 1997. Oppo, D. W., Keigwin, L. D., and McManus, J. F.: Persistent suborbital climate variability in marine isotope stage 5 and Termination II, Paleoceanography, 16, 280–292, 2001. Oppo, D. W., McManus, J. F., and Cullen, J. L.: Abrupt climate events 500000 to 340000 years ago: evidence from subpolar North Atlantic sediments, Science, 279, 1335–1338, doi:10.1126/science.279.5355.1335, 1998. Oppo, D. W., McManus, J. F., and Cullen, J. L.: Evolution and demise of the Last Interglacial warmth in the subpolar North Atlantic, Quaternary Sci. Rev., 25, 3268–3277, 2006. Ozenda, P.: Les végétaux dans la biosphère, Doin, Paris, France, 431~pp., 1982. Pahnke, K., Zahn, R., Elderfield, H., and Schulz, M.: 340000-year centennial-scale marine record of Southern Hemisphere climatic oscillation, Science, 301, 948–952, doi:10.1126/science.1084451, 2003. Pailler, D. and Bard, E.: High frequency palaeoceanographic changes during the past 140000 yr recorded by the organic matter in sediments of the Iberian Margin, Palaeogeogr. Palaeocl., 181, 431–452, 2002. Petit, J. R., Jouzel, J., Raynaud, D., Barkov, N. I., Barnola, J.-M., Basile, I., Bender, M., Chappellaz, J., Davis, M., Delaygue, G., Delmotte, M., Kotyakov, V. M., Legrand, M., Lipenkov, V. Y., Lorius, C., Pépin, L., Ritz, C., Saltzman, E., and Stievenard, M.: Climate and atmospheric history of the past 420000 years from the Vostok ice core, Antarctica, Nature, 399, 429–436, doi:10.1038/20859, 1999. Pflaumann, U., Duprat, J., Pujol, C., and Labeyrie, L. D.: SIMMAX: A modern analog technique to deduce Atlantic sea surface temperatures from planktonic foraminifera in deep-sea sediments, Paleoceanography, 11, 15–35, 1996. Prell, W. L., Imbrie, J., Martinson, D. G., Morley, J. J., Pisias, N. G., Shackleton, N. J., and Streeter, H. F.: Graphic correlation of oxygen isotope stratigraphy application to the late Quaternary, Paleoceanography, 1, 137–162, 1986. Prentice, I. C., Bartlein, P. J., and Webb III, T.: Vegetation and climate change in eastern North America since the Last Glacial Maximum, Ecology, 72, 2038–2056, 1991. Reille, M. and de Beaulieu, J.-L.: Long Pleistocene pollen records from the Praclaux Crater, South-Central France, Quaternary Res., 44, 205–215, 1995. Reille, M., de Beaulieu, J.-L., Svobodova, V., Andrieu-Ponel, V., and Goeury, C.: Pollen analytical biostratigraphy of the last five climatic cycles from a long continental sequence from the Velay region (Massif Central, France), J. Quaternary Sci., 15, 665-685, 2000. Roucoux, K. H., de Abreu, L., Shackleton, N. J., and Tzedakis, P. C.: The response of NW Iberian vegetation to North Atlantic climate oscillations during the last 65 kyr, Quaternary Sci. Rev., 24, 1637–1653, 2005. Roucoux, K. H., Tzedakis, P. C., de Abreu, L., and Shackleton, N. J.: Climate and vegetation changes 180000 to 345000 years ago recorded in a deep-sea core off Portugal, Earth Planet. Sc. Lett., 249, 307–325, 2006. Rousseau, D. D., Hatté, C., Guiot, J., Duzer, D., Schevin, P., and Kukla, G.: Reconstruction of the Grande Pile Eemian using inverse modeling of biomes and $\delta^13$C, Quaternary Sci. Rev., 25, 2806–2819, 2006. Ruddiman, W. F.: Ice-driven CO₂ feedback on ice volume, Clim. Past, 2, 43–55, 2006. Ruddiman, W. F.: The early anthropogenic hypothesis: Challenges and responses, Rev. Geophys., 45, RG4001, doi:10.1029/2006RG000207, 2007. Sakai, K. and Peltier, W. R.: Dansgaard-Oeschger oscillations in a coupled atmosphere-ocean climate model, J. Climate, 10, 949–970, 1997. Sánchez Goñi, M. F., Eynaud, F., Turon, J.-L., and Gendreau, S.: European climatic response to millennial-scale climatic changes in the atmosphere-ocean system during the Last Glacial period, Quaternary Res., 54, 394–403, 2000. Sánchez Goñi, M. F., Eynaud, F., Turon, J.-L., and Shackleton, N. J.: High resolution palynological record off the Iberian margin: direct land-sea correlation for the Last Interglacial complex, Earth Planet. Sc. Lett., 171, 123–137, 1999. Sánchez Goñi, M. F., Landais, A., Fletcher, W., Naughton, F., Desprat, S., and Duprat, J.: Contrasting impacts of Dansgaard – Oeschger events over a western European latitudinal transect modulated by orbital parameters, Quaternary Sci. Rev., 27, 1136–1151, 2008. Sánchez Goñi, M. F., Loutre, M. F., Crucifix, M., Peyron, O., Santos, L., Duprat, J., Malaizé, B., Turon, J.-L., and Peypouquet, J.-P.: Increasing vegetation and climate gradient in western Europe over the Last Glacial Inception (122–110 ka): models-data comparison, Earth Planet. Sc. Lett., 231, 111–130, 2005. Schulz, M., Berger, W. H., Sarnthein, M., and Grootes, P. M.: Amplitude variations of 1470-year climate oscillations during the last 100000 years linked to fluctuations of continental ice mass, Geophys. Res. Lett., 26, 3385–3388, 1999. Shackleton, N. J., Chapman, M., Sanchez-Goñi, M. F., Pailler, D., and Lancelot, Y.: The classic Marine Isotope Substage 5e, Quaternary Res., 58, 14–16, 2002. Shackleton, N. J., Hall, M. A., and Vincent, E.: Phase relationships between millennial-scale events 64000–24000 years ago, Paleoceanography, 15, 565–569, 2000. Siddall, M., Rohling, E. J., Almogi-Labin, A., Hemleben, C., Meischner, D., Schmelzer, I., and Smeed, D. A.: Sea-level fluctuations during the last glacial cycle, Nature, 423, 853–858, doi:10.1038/nature01690, 2003. Siddall, M., Stocker, T. F., Blunier, T., Spahni, R., Schwander, J., Barnola, J.-M., and Chappellaz, J.: Marine Isotope Stage (MIS) 8 millennial variability stratigraphically identical to MIS 3, Paleoceanography, 22, PA1208, doi:10.1029/2006PA001345, 2007. Siegenthaler, U., Stocker, T. F., Monnin, E., Lüthi, D., Schwander, J., Stauffer, B., Raynaud, D., Barnola, J.-M., Fischer, H., Masson-Delmotte, V., and Jouzel, J.: Stable carbon cycle – climate relationship during the Late Pleistocene, Science, 310, 1313–1317, doi:10.1126/science.1120130, 2005. Skinner, L. C. and Shackleton, N. J.: Deconstructing Terminations I and II: revisiting the glacioeustatic paradigm based on deep-water temperature estimates, Quaternary Sci. Rev., 25, 3312–3321, 2006. Spahni, R., Chappellaz, J., Stocker, T. F., Loulergue, L., Hausammann, G., Kawamura, K., Flückiger, J., Schwander, J., Raynaud, D., and Jouzel, J.: Atmospheric methane and nitrous oxide of the late Pleistocene from Antarctic ice cores, Science, 310, 1317–1321, doi:10.1126/science.1120132, 2005. Stirling, C. H., Esat, T. M., Lambeck, K., McCulloch, M. T., Blake, S. G., Lee, D.-C., and Halliday, A. N.: Orbital forcing of the Marine Isotope Stage 9 Interglacial, Science, 291, 290–293, doi:10.1126/science.291.5502.290 2001. Turon, J.-L.: Le palynoplancton dans l'environnement actuel de l'Atlantique nord-oriental, Evolution climatique et hydrologique depuis le dernier maximum glaciaire, Université de Bordeaux I, 313 pp., Bordeaux, France, 1984. Tzedakis, P. C.: Towards an understanding of the response of southern European vegetation to orbital and suborbital climate variability, Quaternary Sci. Rev., 24, 1585–1599, 2005. Tzedakis, P. C., Andrieu, V., de Beaulieu, J.-L., Birks, H. J. B., Crowhurst, S., Follieri, M., Hooghiemstra, H., Magri, D., Reille, M., Sadori, L., Shackleton, N. J., and Wijmstra, T. A.: Establishing a terrestrial chronological framework as a basis for biostratigraphical comparisons, Quaternary Sci. Rev., 20, 1583–1592, 2001. Tzedakis, P. C., Andrieu, V., de Beaulieu, J.-L., Crowhurst, S., Follieri, M., Hooghiemstra, H., Magri, D., Reille, M., Sadori, L., Shackleton, N. J., and Wijmstra, T. A.: Comparison of terrestrial and marine records of changing climate of the last 500000 years, Earth Planet. Sc. Lett., 150, 171–176, 1997. Tzedakis, P. C., Frogley, M. R., Lawson, I. T., Preece, R. C., Cacho, I., and de Abreu, L.: Ecological thresholds and patterns of millennial-scale climate variability: The response of vegetation in Greece during the last glacial period, Geology, 32, 109–112, 2004a. Tzedakis, P. C., McManus, J. F., Hooghiemstra, H., Oppo, D. W., and Wijmstra, T. A.: Comparison of changes in vegetation in northeast Greece with records of climate variability on orbital and suborbital frequencies over the last 450000 years, Earth Planet. Sc. Lett., 212, 197–212, 2003. Tzedakis, P. C., Roucoux, K. H., de Abreu, L., and Shackleton, N. J.: The duration of forest stages in southern Europe and interglacial climate variability, Science, 306, 2231–2235, doi:10.1126/science.1102398, 2004b. Viau, A. E., Gajewski, K., Fines, P., Atkinson, D. E., and Sawada, M. C.: Widespread evidence of 1500 yr climate variability in North America during the past 14000 yr, Geology, 30, 455–458, 2002. Waelbroeck, C., Labeyrie, L., Michel, E., Duplessy, J. C., McManus, J. F., Lambeck, K., Balbon, E., and Labracherie, M.: Sea-level and deep water temperature changes derived from benthic foraminifera isotopic records, Quaternary Sci. Rev., 21, 295–305, 2002. Wijmstra, T. A. and Smit, A.: Palynology of the middle part (30–78 meters) of the 120 m deep section in Northern Greece (Macedonia), Acta Bot. Neerl., 25, 297–312, 1976. Yokokawa, M. and Franz, S. O.: Changes in grain size and magnetic fabric at Blake-Bahama Outer Ridge during the late Pleistocene (marine isotope stages 8–10), Mar. Geol., 189, 123–144, 2002.