#----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # Online_Resource: hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:15309 # Online_Resource: ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2012-grain-size.txt # # Original_Source_URL: # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleolimnology #-------------------- # Contribution_Date # Date: 2013-06-29 #-------------------- # Title # Study_Name: Non-linear Holocene climate evolution in the North Atlantic: a high-resolution, multi-proxy record of glacier activity and environmental change from Hvítárvatn, central Iceland #-------------------- # Investigators # Investigators: Larsen,D.J.;Miller,G.H.;Geirsdóttir,Á.;Ólafsdóttir,S. #-------------------- # Description_and_Notes Description: #-------------------- # Publication # Authors: Larsen, D.J., Miller, G.H., Geirsdottir, A., Olafsdottir, S. # Published_Date_or_Year: 2012 # Published_Title: Non-linear Holocene climate evolution in the North Atlantic: a high resolution, multi-proxy record of glacier activity and environmental change from Hvitarvatn, central Iceland. # Journal_Name: Quaternary Science Reviews # Volume: 39 # Edition: # Issue: # Pages: 14-25 # Report_Number: # DOI: # Publication_Place: # Publisher: # ISBN: # Online_Resource: # Other_Reference_Details: # Full_Citation: # Abstract: Iceland is well situated to monitor North Atlantic Holocene climate variability. Terrestrial sites there offer the potential for well-dated, high-resolution, continuous records of environmental change and/or glacier activity. Laminated sediments from the proglacial lake Hvítárvatn provide a continuous record of environmental change and the development of the adjacent Langjökull ice cap for the past 10.2 ka. Replicate lake sediment cores, collected from multiple locations in the basin, are placed in a secure geochronology by splicing a varve chronology for the past 3 ka with a tephra-constrained, paleomagnetic secular variation derived chronology for older sediments. Multiple proxies, including sedimentation rate, bulk density, ice-rafted debris, sediment organic matter, biogenic silica, and diatom abundance, allow annual to multi-decadal resolution and reveal a dynamic Holocene terrestrial climate. Following regional deglaciation of the main Iceland Ice Sheet, summer temperatures were high enough that mountain ice caps had already melted, or were contributing insignificant sediment to the lake. Pronounced increases in sedimentation rate, sediment density, and the influx of terrestrial organic matter, between 8.7 and 7.9 ka suggest early Holocene warmth was interrupted by two distinct pulses of cold summers leading to widespread landscape destabilization and possibly glacier growth. The Holocene thermal maximum (HTM; 7.9 to 5.5 ka) was characterized by high within-lake productivity and ice-free conditions in the watershed. Neoglaciation is recorded as a non-linear transition toward cooler summers, landscape destabilization, and the inception and expansion of Langjökull beginning ca 5.5 ka, with notable increases in ice cap size and landscape instability at 4.2 and 3.0 ka. The past two millennia are characterized by the abrupt onset of sustained cold periods at ca 550 and 1250 AD, separated by an interval of relative warmth from ca 950 to 1150 AD. The greatest Holocene extent of Langjökull occurred in the nineteenth century and is coincident with peak landscape instability, followed by ice recession throughout the twentieth century. #------------------ # Funding_Agency # Funding_Agency_Name: # Grant: #------------------ # Site_Information # Site_Name: Lake Hvítárvatn03-1 # Location: Iceland # Region: central highlands of Iceland # Country: Iceland # Northernmost_Latitude: 64.641944 # Southernmost_Latitude: 64.641944 # Easternmost_Longitude: -19.840278 # Westernmost_Longitude: -19.840278 # Elevation: 422 m #------------------ # Data_Collection # Collection_Name: HVT grain size # Earliest_Year: 10156 # Most_Recent_Year: -41 # Time_Unit: # Core_Length: # Notes: #------------------ # Species: #------------------ # Chronology: #---------------- # Variables # Short_name What,Material,Error,Units,Seasonality,Archive,Details,Method,Data_type age_BP Age,,,,cal yr bp,,,,,N Silt+Clay% Total Silt+Clay,sediment,,percent,,paleolimnology,,,N #---------------- # Data # Missing_Values: # # Data line format - tab-delimited text, variable short name as header ageBP Silt+Clay% -41 98.37 -15 95.08 9 98.9 23 65.96 59 91.48 103 86.44 124 96.99 182 96.19 194 94.64 194 95.81 231 91.45 322 96.95 389 93.3 458 96.46 471 95.79 550 99.22 567 94.83 742 97.67 786 97.44 905 94.55 944 93.67 973 96.18 1109 94.58 1355 95.29 1413 98.04 1537 98.71 1737 95.44 1757 99.22 2023 99.08 2091 98.45 2267 92.7 2270 90.08 2300 93.98 2456 96.77 2480 98.21 2703 98.04 2796 95.56 3044 97.06 3126 96.06 3266 97.59 3445 97.1 3543 94.66 3596 93.19 3701 97.5 3767 97.55 3816 97.16 3989 92.31 4114 94.09 4149 94.53 4236 96.25 4251 97.18 4379 93.78 4656 93.88 4796 94.78 5040 97.06 5310 90.96 5473 95.39 5676 91.86 5737 92.94 5935 95.69 6160 86.18 6249 82.85 6296 84.78 6372 89.74 6484 88.09 6725 85.43 7222 87.2 7893 77.77 7954 91 8027 96.64 8086 97.15 8145 96.05 8160 97.65 8182 94.47 8199 86.15 8208 90.29 8265 84.09 8310 81.18 8464 86.78 8506 80.6 8610 77.8 8705 77.05 8772 72.93 8843 84.1 8941 71.7 9197 84.99 10156 92.04