# Vestra Gíslholtsvatn, Iceland 2000 Year Biomarker and Geochemical Data #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #----------------------------------------------------------------------- # Template Version 3.0 # Encoding: UTF-8 # 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: https://www.ncdc.noaa.gov/paleo/study/29992 # Description: NOAA Landing Page # Online_Resource: https://www.ncei.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/vestra-gslholtsvatn2020wax.txt # Description: NOAA location of the template # # Original_Source_URL: # Description: # # Description/Documentation lines begin with # # Data lines have no # # # Data_Type: paleolimnology # # Dataset_DOI: # # Parameter_Keywords: geochemistry, physical properties #-------------------- # Contribution_Date # Date: 2020-06-08 #-------------------- # File_Last_Modified_Date # Date: 2020-06-08 #-------------------- # Title # Study_Name: Vestra Gíslholtsvatn, Iceland 2000 Year Biomarker and Geochemical Data #-------------------- # Investigators # Investigators: Richter, N.; Russell, J.M.; Garfinkel, J.; Huang, Y. #-------------------- # Description_Notes_and_Keywords # Description: Biomarker (alkenones and n-alkanes) and geochemical (opal, organic carbon, total nitrogen) data from sediments collected in Vestra Gíslholtsvatn, Iceland for the past 2,000 years. # Alkenones were analyzed from lake sediment cores taken from Vestra Gíslholtsvatn, southwest Iceland in 2008. # Bulk organic and inorganic properties and leaf waxes were analyzed in lake sediment cores collected from Vestra G'slholtsvatn, southwest Iceland in 2008. # Leaf waxes were analyzed in lake sediment cores collected from Vestra G'slholtsv atn in southwest Iceland in 2008. The chronology for the lake sediment core was initially published in Blair et al. (2015). #-------------------- # Publication # Authors: Richter, N., Russell, J.M., Garfinkel, J., Huang, Y. # Published_Date_or_Year: 2021-01-04 # Published_Title: Impacts of Norse settlement on terrestrial and aquatic ecosystems in Southwest Iceland # Journal_Name: Journal of Paleolimnology # Volume: 65 # Edition: # Issue: # Pages: 255-269 # Report_Number: # DOI: 10.1007/s10933-020-00169-3 # Online_Resource: # Full_Citation: # Abstract: Norse colonization of North Atlantic islands in the 1st millennium of the Common Era led to drastic prehistoric environmental changes in these previously “pristine” landscapes. In Iceland, Norse settlement is associated with a rapid decline in birch trees and heightened soil erosion, yet the timing of Norse exploration in the North Atlantic coincided with large climate changes that also influenced Icelandic environments. To date, there are few records that disentangle climatic and human impacts on terrestrial ecosystems, and there has been very little work on the impacts of Norse arrival on Iceland’s aquatic ecosystems. Here we use a high-resolution lake-sediment record from Vestra Gíslholtsvatn (VGHV), southwest Iceland to investigate these processes during the last 2,000 years. Norse arrival (c. 870 CE) in Iceland is followed by a rapid increase in sedimentation rate and a transition in leaf wax n-alkanes indicating a decrease in trees and expansion of grasses. This transition coincides with limnological changes, including increased primary productivity (i.e. C17 n-alkane and biogenic opal fluxes) and shifts in the haptophyte algal community. Many of these changes are still apparent today. Comparisons with a new winter-spring alkenone temperature reconstruction from VGHV and marine sea surface temperature records show little to no correlation between terrestrial and aquatic ecological changes and climate at this time. Similarly, volcanic eruptions recorded in VGHV are not associated with any long-term environmental changes. Rather, the VGHV record suggests that human settlement had a lasting impact on the catchment area of VGHV and changes within the lake ecosystem. #-------------------- # Publication # Authors: Richter, Nora, James M. Russell, Johanna Garfinkel, Yongsong Huang # Published_Date_or_Year: 2020 # Published_Title: Cold season warming in the North Atlantic during the last 2000 years: Evidence from Southwest Iceland # Journal_Name: Climate of the Past # Volume: # Edition: # Issue: # Pages: 1-28 # Report_Number: # DOI: 10.5194/cp-2020-84 # Online_Resource: # Full_Citation: # Abstract: Temperature reconstructions from the Northern Hemisphere (NH) generally indicate cooling over the Holocene which is often attributed to decreasing summer insolation. However, climate model simulations predict that rising atmospheric CO2 concentrations and the collapse of the Laurentian Ice Sheet caused mean annual warming during this epoch. This contrast could reflect a seasonal bias in temperature proxies, and particularly a lack of proxies that record cold (late fall-early spring) season temperatures, or inaccuracies in climate model predictions of NH temperature. We reconstructed winter-spring temperatures during the Common Era (i.e. the last 2000 years) using alkenones, lipids produced by Isochrysidales haptophyte algae that bloom during spring ice-out, preserved in sediments from Vestra Gíslholtsvatn (VGHV), southwest Iceland. Our record indicates that winter-spring temperatures warmed during the last 2000 years, in contrast to most NH averages. Sensitivity tests with a lake energy balance model suggest that warmer winter and spring air temperatures result in earlier ice-off dates and warmer spring lake water temperatures, and therefore warming in our proxy record. Regional air temperatures are strongly influenced by sea surface temperatures (SSTs) during the winter and spring season. SSTs respond to both changes in ocean circulation and gradual changes in insolation. We also found distinct seasonal differences in centennial-scale, cold-season temperature variations in VGHV compared to existing records of summer and annual temperatures from Iceland. Multi-decadal to centennial-scale changes in winter-spring temperatures were strongly modulated by internal climate variability and changes in regional ocean circulation, which can result in winter and spring warming in Iceland even after a major negative radiative perturbation. #------------------ # Funding_Agency # Funding_Agency_Name: Geological Society of America # Grant: #------------------ # Funding_Agency # Funding_Agency_Name: Brown University # Grant: #------------------ # Site_Information # Site_Name: Vestra G'slholtsvatn # Location: Europe>Northern Europe>Iceland # Country: Iceland # Northernmost_Latitude: 63.94517 # Southernmost_Latitude: 63.94517 # Easternmost_Longitude: -20.519212 # Westernmost_Longitude: -20.519212 # Elevation: 61 #------------------ # Data_Collection # Collection_Name: VGHV2020wax # Earliest_Year: 1948 # Most_Recent_Year: -30 # Time_Unit: Cal. Year BP # Core_Length: 2.55 # Notes: #------------------ # Chronology_Information # Chronology: # The chronology for the lake sediment core was initially published by Blair et al. (2015). #---------------- # Variables # # Data variables follow are preceded by "##" in columns one and two. # Data line variables format: one per line, shortname-tab-variable components (what, material, error, units, seasonality, data type,detail, method, C or N for Character or Numeric data, free text) # ## depth depth, , , centimeter, , paleolimnology, , ,N, ## ageBP age, , , calendar year before present, , paleolimnology, , ,N, ## drymass mass, sediment, , gram, , paleolimnology, , ,N, dry sediment sample mass ## C17 C17 n-alkane, sediment, , nanogram, , paleolimnology, , ,N, ## C21 C21 n-alkane, sediment, , nanogram, , paleolimnology, , ,N, ## C23 C23 n-alkane, sediment, , nanogram, , paleolimnology, , ,N, ## C25 C25 n-alkane, sediment, , nanogram, , paleolimnology, , ,N, ## C27 C27 n-alkane, sediment, , nanogram, , paleolimnology, , ,N, ## C29 C29 n-alkane, sediment, , nanogram, , paleolimnology, , ,N, ## C31 C31 n-alkane, sediment, , nanogram, , paleolimnology, , ,N, ## C33 C33 n-alkane, sediment, , nanogram, , paleolimnology, , ,N, ## ACL25-31 average chain length, , , , , paleolimnology, , ,N, Average Chain Length for C25-C31; ACL25-31 values were calculated after Schefuss et al. (2003) # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: NaN # depth ageBP drymass C17 C21 C23 C25 C27 C29 C31 C33 ACL25-31 3.5 -30 1.58 1.1 1.72 4.37 4.51 5.5 4.82 4.6 1.77 27.98 5.5 -19 2.4 20.18 7.66 25.8 24.35 27.46 23.38 21.9 12.04 27.88 7.5 -7 2.82 2.8 3.43 8.46 9.69 12.96 12.61 11.72 4.26 28.12 9.5 4 2.04 14.44 5.38 13.97 13.63 15.82 14.04 13.37 5.15 27.95 11.5 15 1.44 5.81 4.55 11.54 11.65 13.88 11.86 10.72 4.21 27.9 13.5 26 1.43 0.74 0.66 1.89 2.3 3.56 3.08 2.65 0.99 28.05 17.5 48 1.59 1.75 2.39 6.09 6.94 9.31 8.29 7.61 2.97 28.03 19.5 57 1.32 3.33 1.29 3.75 3.88 5.55 5.73 5.99 2.44 28.31 21.5 69 1.63 0.99 2.38 6.38 7.8 11.29 10.41 9.71 3.66 28.12 25.5 91 1.51 5.08 5.96 14.99 16.36 20.47 17.1 15.61 6.15 27.92 31.5 126 1.35 3.95 4.91 12.54 14.17 19.04 16.46 15.53 6.37 28.02 33.5 138 1.19 5.82 4.49 11.82 12.24 16.74 13.99 12.02 5.15 27.94 35.5 151 1.5 4.04 6.31 17.32 18.45 23.94 20.27 18.63 7.45 27.96 39.5 176 1.38 5.23 1.99 6.11 6.53 9.19 9.27 9.76 4.1 28.28 41.5 188 1.67 3.32 4.67 10.48 11.75 15.9 13.77 12.97 5.22 28.03 43.5 202 1.2 0.81 0.84 2.72 3.4 4.95 5.02 4.14 1.59 28.13 45.5 215 1.42 2.69 2.72 8.06 9.47 12.5 10.79 9.55 3.78 27.97 47 225 1.47 15.93 3.77 6.95 8.03 9.5 8.3 7.51 3.16 27.92 48.5 236 1.22 1.12 1.32 4.1 5.36 7.33 6.88 6.49 2.58 28.11 51.5 257 1.64 5.34 6.94 17.99 20.01 26.01 22.39 20.61 8.31 27.98 53.5 272 1.44 4.72 3.79 9.41 9.58 11.86 10.01 9.2 4.06 27.93 55.5 287 1.49 0.65 1.21 3.24 3.99 5.87 5.5 4.99 1.9 28.13 57.5 302 1.24 NaN 0.83 3.43 4.43 6.19 5.79 5.27 2.04 28.1 59.5 317 1.46 3.84 1.43 4.38 6.14 8.87 9.06 8.66 3.49 28.24 61.5 332 1.42 0.52 0.98 3.06 3.74 5.39 4.93 4.6 1.78 28.11 63.5 347 1.51 0.64 0.84 3.38 4.49 6.11 5.28 4.4 1.42 27.95 65.5 363 1.67 4.62 5.12 14.9 17.19 21.16 17.84 15.25 6.12 27.87 67.5 378 1.32 1.16 1 4.05 5.46 7.56 7.17 6.18 2.3 28.07 69.5 393 1.52 7.88 3.66 10.88 14.45 19.49 19 18.9 8.11 28.18 71.5 407 1.51 5.41 3.68 12.69 15.73 20.12 16.81 15 6.22 27.92 73.5 422 1.61 2.99 3.21 11.15 13.64 17.41 15.2 13.51 5.43 27.96 75.5 436 1.67 4.54 2.72 8.88 10 11.7 10.78 9.78 4.13 27.96 79.5 463 1.55 2.09 0.96 3.22 4.92 6.83 6.65 6.03 2.43 28.13 81.5 477 1.79 6.05 4.16 14.25 17.83 23.18 19.83 17.78 7.2 27.96 83.5 489 1.82 1.86 1.52 6.72 8.51 10.75 9.33 8.07 3.24 27.93 85.5 502 1.49 2.44 1.81 6.45 7.97 10.17 8.78 7.73 3.17 27.94 87.5 514 1.52 2.98 3.1 11.78 13.38 15.74 13.18 10.78 4.38 27.8 89.5 526 1.78 2.28 1.59 6 8.46 11.64 10.65 9.62 4.05 28.06 91.5 538 2.32 5.93 5.71 18.13 22.11 28.85 23.4 20.92 8.67 27.91 95.5 559 2.63 1.2 2.82 9.74 11.2 13.18 10.28 8.3 3.28 27.73 99.5 580 2.39 4.18 4.69 14.77 16.44 18.98 14.01 10.37 3.56 27.61 101.5 591 2.74 2.18 3.6 11.11 12.72 16.07 12.71 10.87 4.28 27.83 105.5 611 2.03 5.1 5.72 17.79 20.66 26.03 20.36 17.1 7.02 27.81 109.5 631 1.91 NaN 1.91 7.26 8.76 10.67 8.19 5.89 2.15 27.67 111.5 640 2.09 7.05 7.31 24.86 29.15 36.05 28.3 23.67 9.64 27.79 115.5 659 2.75 5.42 7.31 23.44 26.1 34.18 25.63 22.06 9.06 27.81 119.5 678 2.45 NaN 7.27 23.59 26.34 33.05 23.25 18.3 7.09 27.66 123.5 696 2.49 2.77 3.98 13.22 17.68 25.24 20.06 17.74 7.17 27.94 127.5 714 3.59 2.09 3.85 13.54 19 30.69 24.81 22.68 9.14 28.05 129.5 723 2 9.74 6.04 20.86 25.9 38.22 25.9 21.87 8.38 27.78 131.5 732 2.97 10 8.45 25.98 31.67 47.83 36.15 34.32 14.4 27.98 133.5 741 3.48 9.96 8.95 26.91 33.76 51.22 39.79 38.67 16.02 28.02 137.5 758 2.24 6.98 5.03 19.17 25.82 40.01 32.46 31.05 13.18 28.06 139.5 768 2.11 12.14 4.47 16.62 20.98 32.78 24.14 21.24 8.81 27.92 141.5 777 2.39 1.36 1.45 5.97 9 15.55 13.48 12.71 5.22 28.18 145.2 795 1.79 4.43 1.9 6.06 6.86 8.74 6.64 5.35 2.1 27.76 151.2 824 2.45 6.28 6.12 19.99 24.17 35.59 25.58 24.67 10.39 27.92 155.2 845 1.85 13.43 4.11 15.43 18.07 25.63 19.69 17.84 6.76 27.92 157.2 855 1.55 2.71 2.59 9.06 11.41 16.96 14.02 12.5 5.05 28.01 161.2 876 1.97 1.88 1.68 6.51 9.5 16.52 14.38 13.67 5.45 28.19 163.2 888 1.96 NaN 2.31 8.57 11.91 24.54 15.43 13.75 1.85 27.95 165.2 900 1.86 3.36 1.6 6.1 7.66 11.66 9.23 8.39 3.27 27.99 167.2 912 1.76 1.43 1.42 5.34 7.46 11.79 10.06 9.39 3.71 28.1 169.2 925 1.94 4.59 3.1 11.2 12.9 19.01 16.16 15.75 6.61 28.09 171.2 938 1.91 6.27 4.95 16.99 21.76 35.1 28.37 26.07 11.02 28.06 173.2 952 1.7 7.5 5.88 24.09 25.64 43.63 33.03 24.64 6.45 27.89 175.2 966 1.77 11.85 6.83 26.85 32.71 52.1 41.01 33.72 14.03 27.95 177.2 982 2.01 5.45 5.12 17.45 21.67 33.26 25.35 21.94 9.97 27.93 179.2 998 1.75 1.87 2.51 9.57 13.24 28.9 16.63 12.6 3.18 27.8 181.2 1014 2.18 6.52 5.33 17.85 21.98 34.66 24.8 19.93 8.78 27.84 183.2 1032 1.68 4.35 3.73 17.78 21.83 26.09 16.27 9.15 5.97 27.35 185.2 1050 1.78 3.25 4.53 18.78 20.71 23.73 16.71 11.93 4.15 27.54 191.2 1098 1.63 6.74 2.71 12.9 18.53 24.53 11.57 5.86 8.36 27.16 193.2 1118 1.54 NaN 2.49 13.32 15.03 17.46 10.53 5.02 8.48 27.23 194.8 1135 1.37 6.58 2.83 19.21 21.71 22.01 12.13 6.8 11.07 27.13 196.9 1157 1.36 7.1 4.9 34.09 38.1 43.24 23.14 9.89 13.6 27.08 199.1 1181 1.55 2.29 7.53 11.07 21.16 26.09 13.38 8.27 2.27 27.25 203.2 1225 1.35 6.59 5.02 30.94 33.27 36.23 22.4 9.01 9.13 27.14 205.2 1249 1.53 9.29 4.08 29.45 36.71 43.45 28.37 10.04 3.42 27.2 207.2 1273 1.67 10.5 4.96 29.19 31.44 35.13 18.97 8.36 10.48 27.09 209.2 1297 1.4 2.9 2.22 10.53 12.61 14.75 10.29 5.8 5.98 27.43 211.2 1322 1.75 6.73 3.25 23.66 29.38 33.86 18.45 9.1 7.25 27.16 215.2 1358 1.3 4.88 3.73 26.07 29.62 33.09 18.2 7.31 10.67 27.07 217.2 1384 1.5 8.78 4.54 28.92 31.11 33.41 18.27 7.55 9.27 27.05 219.2 1411 1.79 5 3.68 22.34 26.93 28.86 16.96 6.2 6.35 27.06 221.2 1438 1.48 3.81 2.4 17.23 17.41 18.07 8.39 4.16 1.65 26.97 223.2 1465 1.4 6.6 4.37 28.87 29.08 30.3 15.43 5.99 3.72 26.96 225.1 1492 1.53 2.61 2.64 18.69 18.9 20 9.29 4.46 2.27 26.97 229.2 1543 1.75 2.5 3.5 24.05 24.64 26.09 14.89 5.34 4.8 27.03 231.2 1572 0.93 2.53 2.83 18.09 19.2 22.73 9.78 4.62 3.1 26.99 233.2 1602 1.28 3.99 4.43 31.27 32.21 33.3 21.78 6.17 13.62 27.04 235.2 1632 1.11 NaN 3.21 14.62 15.73 17.87 13.55 6.83 2.74 27.43 237.2 1662 0.59 3 2.98 18.35 20.03 22.83 9.5 4.96 9.8 26.98 239.2 1693 1.15 3.44 3.26 24.52 25.44 25.97 14.05 5.18 10.37 26.97 241.2 1724 1.65 3.07 3.74 28.96 29.84 31.13 19.02 5.5 8.88 27 243.2 1755 2.34 NaN 2 12.14 15.33 17.11 7.79 3.8 5.53 27 245.2 1787 1.17 3.02 3.69 26.17 28.25 31.39 17.13 5.78 10.46 27.01 247.2 1819 1.05 1.48 2.13 14.96 15.79 16.48 7.59 2.98 4.95 26.9 249.2 1852 1.04 2.08 1.72 9.39 9.46 9.59 6.55 2.09 2.89 27.09 251.2 1885 1.4 2.01 2.09 10.11 14.08 14.98 7.63 2.55 3.78 26.93 253.2 1914 1.38 1.37 1.24 6.28 7.26 7.92 5.33 2.06 1.94 27.19 255.2 1948 1.37 3.27 3.06 22.77 21.95 22.15 13.65 4.01 3.91 26.99