A biogenic-silica δ18O record of climate change during the last glacial-interglacial transition in southwestern Alaska

Feng Sheng Hu, Aldo Shemesh

Research output: Contribution to journalArticlepeer-review


Despite growing evidence for environmental oscillations during the last glacial-interglacial transition from high latitude, terrestrial sites of the North Pacific rim, oxygen-isotopic records of these oscillations remain sparse. The lack of data is due partially to the paucity of lakes that contain carbonate sediment suitable for oxygen-isotopic analysis. We report here the first record of oxygen-isotopic composition in diatom silica (δ18OSi) from a lake in that region. δ18OSi increases gradually from 19.0 to 23.5‰ between 12,340 and 11,000 14C yr B.P., reflecting marked climatic warming at the end of the last glaciation. Around 11,000 14C yr B.P., δ18OSi decreases by 1.7‰, suggesting a temperature decrease of 3.5-8.9 °C at the onset of the Younger Dryas (YD) in southwestern Alaska. Climatic recovery began ca. 10,740 14C yr B.P., as inferred from the increase of δ18OSi to a maximum of 23.9‰ near the end of the YD. Our data reveal that a YD climatic reversal in southwestern coastal areas of Alaska occurred, but the YD climate did not return to full-glacial conditions.

Original languageEnglish (US)
Pages (from-to)379-385
Number of pages7
JournalQuaternary Research
Issue number3
StatePublished - May 2003


  • Alaska
  • Lake sediment
  • North Pacific
  • Oxygen isotopes
  • Paleoclimate
  • Younger Dryas

ASJC Scopus subject areas

  • Arts and Humanities (miscellaneous)
  • Earth-Surface Processes
  • Earth and Planetary Sciences(all)


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