Itilliq Lake, Baffin Island 2000 Year Geochemical and Chironomid Data Thomas, E.K.; Briner, J.P.; Axford, Y.; Francis, D.R.; Miller, G.H.; Walker, I.R. Thomas, E.K. Briner, J.P. Axford, Y. Francis, D.R. Miller, G.H. Walker, I.R. Arctic earth science/paleoclimate/insect|paleolimnology (total head capsules,sediment,null,count,null,insect|paleolimnology,null,null,N,total identified) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Heterotrissocladius sp.) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Tanytarsina) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Micropsectra sp.) earth science/paleoclimate/paleolimnology (nitrogen,sediment,null,percent,null,paleolimnology,null,elemental analysis,N,null) earth science/paleoclimate/paleolimnology (delta 13C,sediment,null,per mil PDB,null,paleolimnology,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Cricotopus/Orthocladius) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Pentaneurini) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Abiskomyia sp.) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Corynoneura/Thienemanniella) earth science/paleoclimate/insect|paleolimnology (age,null,null,year Common Era,null,insect|paleolimnology,null,null,N,null) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Sergentia sp.) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Zalutschia sp.) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Tanytarsus lugens/Corynocera oliveri type) earth science/paleoclimate/paleolimnology (biogenic silica,sediment,null,percent,null,paleolimnology,null,spectrophotometry,N,null) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Chironomus sp.) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Paracladius sp.) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Protanypus sp.) earth science/paleoclimate/paleolimnology (carbon/nitrogen,sediment,null,dimensionless,null,paleolimnology,null,elemental analysis,N,total organic carbon/total nitrogen) earth science/paleoclimate/paleolimnology (chlorophyll,sediment,null,dimensionless,null,paleolimnology,null,spectrophotometry,N,650-750nm; relative absorbance value chlorophyll a) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Orthocladius trigonolabis) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Orthocladiinae) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Cricotopus sp.) earth science/paleoclimate/insect|paleolimnology (depth,null,null,centimeter,null,insect|paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (delta 15N,sediment,null,per mil AIR,null,paleolimnology,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/paleolimnology (carbon,sediment,null,percent,null,paleolimnology,null,elemental analysis,N,null) earth science/paleoclimate/paleolimnology (organic matter,sediment,null,percent,null,paleolimnology,null,loss on ignition,N,null) earth science/paleoclimate/insect|paleolimnology (total head capsules,sediment,null,count per gram,null,insect|paleolimnology,null,null,N,null) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Psectrocladius sp.) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Paratanytarsus sp.) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Orthocladius oliveri) earth science/paleoclimate/insect|paleolimnology (identified midge,null,null,percent,null,insect|paleolimnology,null,null,N,Mesocricotopus sp.) earth science/paleoclimate/paleolimnology earth science/paleoclimate/paleolimnology (Itilliq Lake>LATITUDE 69.9917>LONGITUDE -67.1167) We generate a multi-proxy sub-centennial-scale reconstruction of environmental change during the past two millennia from Itilliq Lake, Baffin Island, Arctic Canada. Our reconstruction arises from a finely subsectioned 210Pb- and 14C-dated surface sediment core and includes measures of organic matter (e.g., chlorophyll a; carbon-nitrogen ratio) and insect (Diptera: Chironomidae) assemblages. Within the past millennium, the least productive, and by inference coldest, conditions occurred ca. AD 1700-1850, late in the Little Ice Age. The 2000-yr sediment record also reveals an episode of reduced organic matter deposition during the 6th-7th century AD; combined with the few other records comparable in resolution that span this time interval from Baffin Island, we suggest that this cold episode was experienced regionally. A comparable cold climatic episode occurred in Alaska and western Canada at this time, suggesting that the first millennium AD cold climate anomaly may have occurred throughout the Arctic. Dramatic increases in aquatic biological productivity at multiple trophic levels are indicated by increased chlorophyll a concentrations since AD 1800 and chironomid concentrations since AD 1900, both of which have risen to levels unprecedented over the past 2000 yr. STUDY NOTES: High-resolution multiproxy lake sediment record from Arctic Canada for the past 2,000 years. Data include organic matter content and insect assemblages as proxies of productivity, interpreted as a temperature signal. The 51-cm-long surface core (05ITLSC) was recovered from Itilliq Lake in 2005. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Thomas, E.K. Investigator : Briner, J.P. Investigator : Axford, Y. Investigator : Francis, D.R. Investigator : Miller, G.H. Investigator : Walker, I.R. 2011-04-29 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/11130 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/canada/baffin/itilliq2011.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/canada/baffin/itilliq2011.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/canada/baffin/itilliq2011.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/canada/baffin/itilliq2011.txt English https://www.ncdc.noaa.gov/paleo/study/11130 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/canada/baffin/itilliq2011.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/canada/baffin/itilliq2011.txt Thomas, E.K., J.P. Briner, Y. Axford, D.R. Francis, G.H. Miller, and I.R. Walker. 2011. A 2000-yr-long multi-proxy lacustrine record from eastern Baffin Island, Arctic Canada reveals first millennium AD cold period. Quaternary Research, Vol. 75, Issue 3, May 2011, pp. 491-500. doi:10.1016/j.yqres.2011.03.003 START YEAR: -841 AD * END YEAR: 2005 AD -67.1167 69.9917 -67.1167 69.9917