Journal of Paleolimnology

, Volume 24, Issue 1, pp 29–41

Late quaternary paleoclimatic reconstructions for interior Alaska based on paleolake-level data and hydrologic models

  • Valerie A. Barber
  • Bruce P. Finney
Article

DOI: 10.1023/A:1008113715703

Cite this article as:
Barber, V.A. & Finney, B.P. Journal of Paleolimnology (2000) 24: 29. doi:10.1023/A:1008113715703

Abstract

Hydrologic models are developed for two lakes in interior Alaska to determine quantitative estimates of precipitation over the past 12,500 yrs. Lake levels were reconstructed from core transects for these basins, which probably formed prior to the late Wisconsin. Lake sediment cores indicate that these lakes were shallow prior to 12,500 yr B.P. and increased in level with some fluctuation until they reached their modern levels 4,000-8,000 yr B.P. Evaporation (E), evapotranspiration (ET), and precipitation (P) were adjusted in a water-balance model to determine solutions that would maintain the lakes at reconstructed levels at key times in the past (12,500, 9,000 and 6,000 yr B.P.). Similar paleoclimatic solutions can be obtained for both basins for these times. Results indicate that P was 35-75% less than modern at 12,500 yr B.P., 25-45% less than modern at 9,000 yr B.P. and 10-20% less than modern at 6,000 yr B.P. Estimates for E and ET in the past were based on modern studies of vegetation types indicated by fossil pollen assemblages. Although interior Alaska is predominantly forested at the present, pollen analyses indicate tundra vegetation prior to about 12,000 yr B.P. The lakes show differing sensitivities to changing hydrologic parameters; sensitivity depends on the ratio of lake area (AL) to drainage basin (DA) size. This ratio also changed over time as lake level and lake area increased. Smaller AL to DA ratios make a lake more sensitive to ET, if all other factors are constant.

Alaskahydrologyevapotranspirationpaleoprecipitationpaleoclimateslakes

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Valerie A. Barber
    • 1
  • Bruce P. Finney
    • 2
  1. 1.Institute of Marine ScienceUniversity of Alaska FairbanksFairbanksUSA
  2. 2.Institute of Marine ScienceUniversity of Alaska FairbanksFairbanksUSA