A 3000-year varved record of glacier activity and climate change from the proglacial lake Hvítárvatn, Iceland Larsen, D.J.; Miller, G.H.; Geirsdóttir, A.; Thordarson, T. Larsen, D.J. Miller, G.H. Geirsdóttir, A. Thordarson, T. Arctic Little Ice Age (LIA) Medieval Warm Period temperature earth science/paleoclimate/paleolimnology (age,null,null,year Common Era,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (carbon/nitrogen,sediment,null,dimensionless,null,paleolimnology,null,elemental analysis,N,null) earth science/paleoclimate/paleolimnology (varve thickness,null,null,centimeter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (organic carbon,sediment,null,weight percent,null,paleolimnology,null,elemental analysis,N,null) earth science/paleoclimate/paleolimnology (organic carbon,sediment,null,milligram per square centimeter per year,null,paleolimnology,null,elemental analysis,N,null) earth science/paleoclimate/paleolimnology earth science/paleoclimate/paleolimnology (Lake Hvítárvatn03-3>LATITUDE 64.63805>LONGITUDE -19.85912) (Lake Hvítárvatn03-1>LATITUDE 64.64172>LONGITUDE -19.83995) (Lake Hvítárvatn03-2>LATITUDE 64.64305>LONGITUDE -19.84928) A suite of environmental proxies in annually laminated sediments from Hvítárvatn, a proglacial lake in the central highlands of Iceland, are used to reconstruct regional climate variability and glacial activity for the past 3000 years. Sedimentological analysis is supported by tephrostratigraphy to confirm the continuous, annual nature of the laminae, and a master varve chronology places proxies from multiple lake cores in a secure geochronology. Varve thickness is controlled by the rate of glacial erosion and efficiency of subglacial discharge from the adjacent Langjökull ice cap. The continuous presence of glacially derived clastic varves in the sediment fill confirms that the ice cap has occupied the lake catchment for the duration of the record. Varve thickness, varve thickness variance, ice rafted debris, total organic carbon (mass flux and bulk concentration), and C:N of sedimentary organic matter, reveal a dynamic late Holocene climate with abrupt and large-scale changes in ice-cap size and landscape stability. A first-order trend toward cooler summers and ice-cap expansion is punctuated by notable periods of rapid ice cap growth and/or landscape instability at ca 1000 BC, 600 BC, 550 AD and 1250 AD. The largest perturbation began ca 1250 AD, signaling the onset of the Little Ice Age and the termination of three centuries of relative warmth during Medieval times. Consistent deposition of ice-rafted debris in Hvítárvatn is restricted to the last 250 years, demonstrating that Langjökull only advanced into Hvítárvatn during the coldest centuries of the Little Ice Age, beginning in the mid eighteenth century. This advance represents the glacial maximum for at least the last 3 ka, and likely since regional deglaciation 10 ka. The multi-centennial response of biological proxies to the Hekla 3 tephra deposition illustrates the significant impact of large explosive eruptions on local environments, and catchment sensitivity to perturbations. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Larsen, D.J. Investigator : Miller, G.H. Investigator : Geirsdóttir, A. Investigator : Thordarson, T. 2013-03-11 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/14730 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-3varvethickness.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-1geochem.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-1varvethickness.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-2geochem.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-2varvethickness.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-3varvethickness.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-1geochem.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-1varvethickness.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-2geochem.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-2varvethickness.txt English https://www.ncdc.noaa.gov/paleo/study/14730 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-3varvethickness.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-1geochem.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-1varvethickness.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-2geochem.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2011-2varvethickness.txt Larsen, D.J., Miller, G.H., Geirsdóttir, Á., Thordarson, T., 2011. A 3000-year varved record of glacier activity and climate change from the proglacial lake Hvítárvatn. Quaternary Science Reviews 30, 2715-2731. START YEAR: -1026 AD * END YEAR: 2002 AD -19.85912 64.63805 -19.83995 64.64305