NOAA/WDS Paleoclimatology - KR02 Lake Surface Temperature Reconstructions during the Past 11000 Years

Changes in chironomid species assemblages and community dynamics at Lake KR02, western Victoria Island were analysed to produce a record of environmental change over the Holocene for the western Arctic. Past air temperatures were inferred from the chironomid record using transfer function and modern analogue techniques, and past lake water pH was reconstructed using sediment carbonate and biogenic silica content. The early-Holocene (10.2–6.5 ka) was a warm period of high aquatic and terrestrial production. A further change in environmental conditions occurred at 4 ka and lasted for the next two millennia. Conditions warmed abruptly at 1.6 ka, and rapidly cooled at ~1.0 ka. A warming then started at 0.14 ka and continued through to recent times, although temperatures still remained cooler than those experienced prior to 6.5 ka. The climatic changes over the Holocene as recorded at Lake KR02 are consistent with those inferred from independent records from other sites on Victoria Island and across the Arctic.