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Biogenic silica concentration as a high‐resolution, quantitative temperature proxy at Hallet Lake, south‐central Alaska
Author(s) -
McKay Nicholas P.,
Kaufman Darrell S.,
Michelutti Neal
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl032876
Subject(s) - proxy (statistics) , climate change , paleoclimatology , context (archaeology) , climatology , biogenic silica , geology , sediment , high resolution , temperature record , environmental science , physical geography , oceanography , geography , geomorphology , paleontology , remote sensing , machine learning , computer science
High‐resolution, quantitative temperature records are valuable for placing recent warming in the context of long‐term, natural climate variability. Here we use biogenic silica (BSi) concentrations preserved in lacustrine sediment from an oligotrophic lake to quantitatively reconstruct air temperature at Hallet Lake in south‐central Alaska. Mean June through August temperature measured over the past 80 yr at Valdez (Alaska) correlate with BSi from Hallet Lake (r = 0.87, p = 0.01). We chose a nested function to model the non‐linear relation between summer temperature and BSi in the calibration data set, and to reconstruct temperature for the past 2 ka. Our BSi‐inferred temperature reconstruction shows synchronous changes with independent paleoclimatic proxies for southern Alaska, and provides evidence for a greater rate and magnitude of 20th century temperature warming at Hallet Lake than recorded by other quantitative temperature proxies in the region.