Climatic Change

, Volume 26, Issue 2, pp 143–169

Glacial geological evidence for the medieval warm period

  • Jean M. Grove
  • Roy Switsur

DOI: 10.1007/BF01092411

Cite this article as:
Grove, J.M. & Switsur, R. Climatic Change (1994) 26: 143. doi:10.1007/BF01092411


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.

Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • Jean M. Grove
    • 1
  • Roy Switsur
    • 2
  1. 1.Girton CollegeCambridgeU.K.
  2. 2.Wolfson CollegeCambridgeU.K.