Abstract
It is hypothesised that the Medieval Warm Period was preceded and followed by periods of moraine deposition associated with glacier expansion. Improvements in the methodology of radiocarbon calibration make it possible to convert radiocarbon ages to calendar dates with greater precision than was previously possible. Dating of organic material closely associated with moraines in many montane regions has reached the point where it is possible to survey available information concerning the timing of the medieval warm period. The results suggest that it was a global event occurring between about 900 and 1250 A.D., possibly interrupted by a minor readvance of ice between about 1050 and 1150 A.D.
Similar content being viewed by others
References
Aeschlimann, H.: 1983,Zur Geschichte des Italienischen Mont Blanc Gebietes: Val Veni-Val Ferret-Ruitor, Unpublished Dissertation, Geographischen Institut der Universität Zürich.
Aitchison, T. C.et al.: 1989, ‘A Comparison of Methods Used for the Calibration of Radiocarbon Ages’,Radiocarbon 31, 846–64.
Benedict, J. B.: 1976, ‘Khumbu Glacier Series’,Radiocarbon 18, 177–8.
Bless, R.: 1984, ‘Beitrage zur Spät- und Postglazialen Geschichte der Gletscher im Nordöstlichen Mont Blanc Gebiet’,Phys. Geogr. 15, 1–116.
Bradley, R. S. and Jones, P. D.: 1992a, ‘When Was the “Little Ice Age” ’, in Mikami, T. (Ed.),Proceedings of the International Symposium on the Little Ice Age Climate, Tokyo Metropolitan University.
Bradley, R. S. and Jones, P. D.: 1992b,Climate since A.D. 1500, Routledge, London and New York.
Bradley, R. S. and Jones, P. D.: 1993, ‘“Little Ice Age” Summer Temperature Variations: Their Nature and Relevance to Recent Global Warming Trends’,The Holocene 3, 367–76.
Burrows, C. J.: 1973, ‘Studies of Some Glacial Moraines in New Zealand - 2. Ages of Moraines of the Mueller, Hooke and Tasman Glaciers (S79)’,New Zeal. Geol. Geophys. 16, 831–55.
Burrows, C. J.: 1979, ‘A Chronology for Cool-Climate Episodes in the Southern Hemisphere 12000-1000 yr. BP’,Palaeogeogr. Palaeoclimatol. Palaeoecol. 27, 287–347.
Burrows, C. J.: 1980, ‘Radiocarbon Dates for Post-Otiran Glacial Activity in the Mt. Cook Region, New Zealand’,New Zeal. J. Geol. Geophys. 23, 239–48.
Burrows, C. J. and Greenland, D. E.: 1979, ‘An Analysis of the Evidence for Climatic Change in New Zealand in the Last Thousand Years: Evidence from Diverse Natural Phenomena and from Instrumental Records’,J. Roy. Soc. New Zeal. 9, 321–73.
Calkin, P. E.: 1988, ‘Holocene Glaciation of Alaska (and Adjoining Yukon Territory, Canada)’,Quatern. Sci. Rev. 7, 159–84.
Calkin, P. E. and Ellis, J. M.: 1981, ‘A Cirque Glacier Chronology Based on Emergent Lichens and Mosses’,J. Glaciol. 27, 512–5.
Clapperton, C. M. and Sugden, D. E.: 1988, ‘Holocene Glacier Fluctuations in South America and Antarctica’,Quatern. Sci. Rev. 7, 185–98.
Egan, C. P.: 1971,Contribution to the Late Neoglacial History of the Lynn Canal and Taku Valley Sections of the Alaska Boundary Range, PhD Dissertation, State University, East Lancing, Michigan.
Fushini, H.; 1977, ‘Glaciation in the Khumbu Himal’,Seppyo, J. Jap. Soc. Snow Ice 39, 60–7.
Fushini, H.: 1978, ‘Glaciation in the Khumbu Himal’,Seppyo, J. Jap. Soc. Snow Ice 40, 71–7.
Gellatly, A. F., Chinn, T. J. H., and Röthlisberger, F.: 1988, ‘Holocene Glacier Variations in New Zealand: A Review’,Quatern. Sci. Rev. 7, 227–42.
Griffey, N. J. and Matthews, J. A.: 1978, ‘Major Neoglacial Expansion Episodes in Southern Norway: Evidence from Moraine Stratigraphy with C14 Dates on Buried Paleosols and Moss Layers’,Geograf. Annal. 60(A), 73–96.
Grove, J. M.: 1985, ‘The Timing of the Little Ice Age in Scandinavia’, in Tooley, M. J. and Sheail, G. M. (eds.),The Climatic Scene, Allen and Unwin, London.
Grove, J. M.: 1988,The Little Ice Age, Methuen, London and New York.
Grove, J. M. and Orombelli, G.: ‘The Southern Region of Europe; the Alps, Italy and the Pyrenees’, in Boulton, G. S. and Mason, P. (eds.),Evaluation of Climate Proxy Data in Relation to the European Holocene, Special issue: ESF Project European Climate and Man.Paläoklimaforsch. Palaoclim. Res., in press.
Gouze, P.,et al.: 1986, ‘Interpretation Paleoclimatique des Oscillations des Glaciers au Cours des 20 Derniers Millenaires dans les Regions Tropicales: Example des Andes Boliviennes’,Compte Rend. L'Acad. Sci. Paris 303 (II), 219–23.
Heuser, C. J.: 1956, ‘Postglacial Environments in the Canadian Rocky Mountains’,Ecol. Monogr. 26, 253–302.
Holzhauser, P.: 1984a, ‘Zur Geschichte der Aletschgletscher und des Fieschergletscher’,Phys. Geogr. 13, 1–448.
Holzhauser, P.: 1988, ‘Methoden zur Rekonstruktion von Gletscherschwankungen’,Die Alpen 64, 135–65.
Holzhauser, P.: 1984b, ‘Rekonstruktion von Gletscherschwankungen mit Hilfe Fossiler Holzer’,Geograph. Helv. 39, 3–15.
Karlén, W.: 1988, ‘Scandinavian Glacial and Climatic Fluctuations during the Holocene’,Quatern. Sci. Rev. 7, 100–209.
Lamb, H. H.: 1965, ‘The Early Medieval Warm Period and Its Sequel’,Paleogeogr., Paleoclimatol., Paleoecol. 1, 13–37.
Luckman, B. H. and Osborn, G. D.: 1979, ‘Holocene Glacier Fluctuations in the Middle Canadian Rocky Mountains’,Quatern. Res. 25, 10–24.
Luckmann, B. H.: 1986, ‘Reconstruction of Little Ice Age Events in the Canadian Rocky Mountains’,Geograph. Phys. Quatern. XL, 17–28.
Luckman, B. H.: 1993, ‘Neoglacial Glacier Fluctuations in the Canadian Rockies’,Quatern. Res. 39, 144–53.
Lütschg, O.: 1926, ‘Über Niederschlag und Abfluss im Hochgebirge, Sonderdarstellung des Mattmarkgebietes’,Schweizerischer Wasserwirtschaftverband, Verbandschrift C14, Veröffentlichung der Schweizerischen Meteorologischen Zentralanstalt in Zürich, Zürich Sekretariat des Schweizerischen Wasserwirtschaftstverbandes.
Kinzl, H.: 1932, ‘Die Grössten Nacheiszeitlichen Gletschervorstösse in den Schweizer Alpen und in der Mont-Blanc-Gruppe’,Zeitschr. Gletscherk. 20, 269–397.
Mann, D. H.: 1986, ‘Reliability of a Fjord Glacier's Fluctuations for Paleoclimatic Reconstruction’,Quatern. Res. 25, 10–24.
Matthews, J. A.: 1984, ‘Limitations of C14 Dates from Buried Soils in Reconstructing Glacier Variations and Holocene Climate’, in Morner, N. A. and Karlén, W. (eds.),Climatic Changes on a Yearly to Millennial Basis: Geological, Historical and Instrumental Records, 281-90.
Matthews, J. A.: 1985, ‘14C Dating of Paleosols, Pollen Analysis and Landscape Change: Studies from Low- and Mid-Alpine Belts of Southern Norway’, in Boerdman, J. (ed.),Soils and Quaternary Landscape Evolution, John Wiley London, pp. 87–116.
Mayr, F.: 1964, ‘Untersuchungen über Ausmass und Folgen der Klima- und Gletscherswankungen seit dem Beginn der postglazialen Wärmezeit’,Zeitschr. Geomorphol. 8, 257–85.
Mercer, J. H.: 1965, ‘Glacier Variations in Southern Patagonia’,Geograph. Rev. 55, 390–413.
Mercer, J. H.: 1968, ‘Variations of Some Patagonian Glaciers since the Late Glacial I’,Amer. J. Sci. 266, 1–25.
Mercer, J. H.: 1970, ‘Variations of Some Patagonian Glaciers since the Late Glacial II’,Amer. J. Sci 269, 91–109.
Mercer, J. H.: 1976, ‘Glacial History of Southernmost South America’,Quatern. Res. 6, 125–66.
Mercer, J. H. and Palacios, O.: 1977, ‘Radiocarbon Dating of the Last Glaciation in Peru’,Geol. 5, 600–4.
Miller, G. H.: 1973, ‘Late Quaternary Glacial and Climatic History of Northern Cumberland Peninsula, East Baffin Island, NWT, Canada’,Quatern. Res. 3, 561–83.
Nesje, A.: 1991, ‘Holocene Glacial and Climatic History of the Jostedalen Region, Western Norway' Evidence from Lake Sediments and Terrestial Deposits’,Quatern Sci. Rev. 10, 87–114.
Nesje, A. and Dahl, S. D.: 1991, ‘Holocene Variations of Blaisen, Hardangerjoklen, Central South Norway’,Quatern. Res. 35, 25–40.
Nesje, A. and Rye, N.: 1993, ‘Late Holocene Glacial Activity at Sandskard Fonna, Jostedalsbreen Area, Western Norway’,Norsk Geogr. Tidsskr. 47, 21–8.
Nesje, A.et al.: 1991, ‘Holocene Glacial and Climatic History of the Jostedalsbreen Region, Western Norway; Evidence from Lake Sediments and Terrestial Deposits’,Quatern. Sci. Rev. 10, 87–114.
Oeschger, H. and Röthlisberger, H.: 1961, ‘Datierung Eines Ehemaligen Standes des Aletschgletschers durch Radioaktivitätsmessung an Holsproben und Bemerkungen zu Holsfunden an Weiteren Gletschern’,Zeitschr. Gletscherk. Glazialgeol. 4, 191–205.
Orombelli, G. and Porter, S. C.: 1982, ‘Late Holocene Fluctuations of Brenva Glacier’,Geogr. Fis. Dinam. Quatern. 5, 14–37.
Osborn, G.: 1986, ‘Lateral Moraine Stratigraphy and Neoglacial History of Bugaboo Glacier, British Columbia’,Quatern. Res. 26, 171–8.
Osborn, G. and Luckman, B. H.: 1988, ‘Holocene Glacier Fluctuations in the Canadian Cordillera (Alberta and British Columbia)’,Quatern. Sci. Rev. 7, 115–28.
Porter, S. C.: 1981, ‘Lichenometric Studies in the Cascade Range of Washington: Establishment ofRhizocarpon Geographicum Growth Curves on Mt. Rainier’,Arc. Alp. Res. 13, 11–23.
Porter, S. C. and Orombelli, G.: 1986, ‘Glacier Contraction during the Middle Holocene in the Western Italian Alps: Evidence and Implications’,Geol. 13, 296–8.
Rabot, C.: 1902, ‘Essai de Chronologie des Variations Glaciaires’,Bull. Geogr. Histor. Descript. 285-327.
Röthlisberger, F.: 1986,10000 Jahre Gletschergeschichte der Erde, Mit einem Beitrag von M. A. Geyh, Sauerländer, Aarau und Frankfurt am Main.
Röthlisberger, F. and Schneebeli, W.: 1979, ‘Genesis of Lateral Moraine Complexes, Demonstrated by Fossil Soils and Trunks: Indicators of Postglacial Climatic Fluctuations’, in Schluchter, E. (ed.),Moraines and Varves, Balkema, Rotterdam, pp. 387–419.
Röthlisberger, F.,et al.: 1980, ‘Holocene climatic Fluctuations. Radiocarbon Dating of Fossil Soils (fAh) and Wood from Moraines and Glaciers in the Alps’,Geogr. Helv. 35, 21–52.
Röthlisberger, F. and Geyh, M. A.: 1985a, ‘Glacier Variations in the Himalayas and Karakorum’,Zeitschr. Gletscher, Glazialgeol. 21, 237–49.
Röthlisberger, F. and Geyh, M. A.: 1985b, ‘Gletscherschwankungen der Nacheiszeit in der Cordillera Blanca (Peru) und den Südlichen Anden Chiles und Argentiniens’,Zentralbl. Geol. Paleoontol. 11, 1611–3.
Ryder, J. M. and Thomson, B.: 1986, ‘Neoglaciation in the Southern Coast Mountains of British Columbia: Chronology of Events Prior to the Late Neoglacial Maximum’,Canad. J. Earth Sci. 23, 273–87.
Sacco, F.: 1917, ‘I Ghiacciai Italiani del Gruppo Monte Bianco’,Boll. Comit. Glaciol. Ital. Ser. 2.3, 21–102.
Seltzer, G. O.: 1990, ‘Recent Glacial History and Paleoclimate of the Peruvian-Bolivian Andes’,Quatern. Sci. Rev. 9, 137–52.
Stuiver, M. and Pearson, G. W.: 1986, ‘High Precision Calibration of the Radiocarbon Timescale A. D. 1950-500 B. C.’,Radiocarbon 28, 805–38.
Stuiver, M. and Pearson, G. W.: 1993, ‘High-Precision Bidecadal Calibration of the Radiocarbon Timescale A. D. 1950-500 B. C.’,Radiocarbon 35, 1–23.
Suess, H. E.: 1970, ‘Bristlecone Pine Calibration of the Radiocarbon Timescale 5200 B. C. to Present’, in Olson, I. U. (ed.),Radiocarbon Variations and Absolute Chronology, Interscience, New York.
Tuthill, S. J., Field, W. O., and Clayton, L.: 1966, ‘Past Earthquake Studies of the Sherman and Sheridan Glaciers’, inThe Great Alaskan Earthquakes of 1964 (Hydrology Volume), National Academy of Sciences, Washington, D. C. Publication 163, pp. 318–28.
Villalba, R.: 1990, ‘Climatic Fluctuations in Northern Patagonia during the Last Thousand Years as Inferred from Tree Rings’,Quatern Res. 34, 346–60.
Wardle, P.: 1973, ‘Variations of Glaciers in Westland National Park and the Hooker Range’,New Zeal. J. Botany 11, 349–88.
Wheeler, J. O.: 1964, ‘Selkirk and Monash Mountains: Recent Glacier Fluctuations’,Canad. Geophys. Bull. 17, 1267.
Williams, V. S.: 1983, ‘Present and Former Equilibrium Line Altitudes near Mt. Everest, Nepal and Tibet’,Arc. Alp. Res. 15, 201–11.
Willis, E. H., Munnich, K. O., and Tauber, H.: 1960, ‘The Variations in Atmospheric Radiocarbon Activity over the Past 1800 Years’,Amer. J. Sci. Radiocarb. Suppl. 2, 1–4.
Worsley, P. and Alexander, M.: 1975, ‘Neoglacial Paleoenvironmental Change at Engabreen, Svartisen, Holandsfiord, North Norway’,Norges Geol. Underokelse 321, 37–66.
Wright, H. E.: 1984, ‘Late Glacial and Late Holocene Moraines in the Cerros Cuchpanga, Central Peru’,Quatern. Res. 21, 275–85.
Zumbühl, H. J. and Holzhauser, H.: 1990, ‘Alpengletscher in den Kleinen Eiszeit’,Geogr. Bern. 31, 3–36.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Grove, J.M., Switsur, R. Glacial geological evidence for the medieval warm period. Climatic Change 26, 143–169 (1994). https://doi.org/10.1007/BF01092411
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01092411