# Abrupt Holocene climate transitions in the northern North Atlantic region recorded by synchronized lacustrine records in Iceland #----------------------------------------------------------------------- # 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: http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:16279 # Online_Resource: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvt-geirsdottir-2013-resampled-cn.txt # # Original_Source_URL: # # Description/Documentation lines begin with # # Data lines have no # # # Archive: paleolimnology #-------------------- # Contribution_Date # Date: 2014-02-25 #-------------------- # Title # Study_Name: Abrupt Holocene climate transitions in the northern North Atlantic region recorded by synchronized lacustrine records in Iceland #-------------------- # Investigators # Investigators: Geirsdóttir,A.;Miller.G.H.;Larsen,D.J.;Ólafsdóttir,S. #-------------------- # Description_Notes_and_Keywords # Description: Keywords - Iceland, Lake sediment, Holocene paleoclimate, Abrupt climate transitions, 8.2 Event, Holocene Thermal Maximum, Neoglaciation, Medieval warm period, Little Ice Age, Geochemistry #-------------------- # Publication # Authors: Geirsdóttir Á., G.H. Miller, D.J. Larsen, S. Ólafsdóttir # Published_Date_or_Year: 2013 # Published_Title: Abrupt Holocene climate transitions in the northern North Atlantic region recorded by synchronized lacustrine records in Iceland # Journal_Name: Quaternary Science Reviews # Volume: 70 # Edition: # Issue: # Pages: 48-62 # DOI: http://dx.doi.org/10.1016/j.quascirev.2013.03.010 # Online_Resource: # Full_Citation: # Abstract: Two high-sediment-accumulation-rate Icelandic lakes, the glacial lake Hvítárvatn and the non-glacial lake Haukadalsvatn, contain numerous tephra layers of known age, which together with highresolution paleomagnetic secular variations allow synchronization with a well-dated marine core from the shelf north of Iceland. A composite standardized climate record from the two lakes provides a single time series that efficiently integrates multi-proxy data that reflect the evolution of summer temperatures through the Holocene. The first-order trends in biogenic silica (BSi), d13C, and C:N rise relatively abruptly following deglaciation, reaching maximum values shortly after 8 ka following a complex minimum between 8.7 and 8.0 ka. The Holocene Thermal Maximum (HTM) in the lakes is marked by all proxies, with a sharp transition out of the 8 ka cold event into peak summer warmth by 7.9 ka, and continuing warm with some fluctuations until 5.5 ka. Decreasing summer insolation after the HTM is reflected by incremental cooling, initially w5.5 ka, with subsequent cold perturbations recorded by all proxies 4.3 to 4.0 ka and 3.1 to 2.8 ka. The strongest disturbance occurred after 2 ka with initial summer cooling occurring between 1.4 and 1.0 ka, followed by a more severe drop in summer temperatures after 0.7 ka culminating between 0.5 and 0.2 ka. Following each late Holocene cold departure, BSi re-equilibrated at a lower value independent of the sediment accumulation rate. Some of the abrupt shifts may be related to Icelandic volcanism influencing catchment stability, but the lack of a full recovery to pre-existing values after the perturbation suggests increased periglacial activity, decreased vegetation cover, and glacier growth in the highlands of Iceland. The similarity in timing, direction and magnitude of our multi-proxy records from glacial and non-glacial lakes, and from the adjacent marine shelf, suggests that our composite record reflects large-scale shifts in ocean/atmosphere circulation throughout the northern North Atlantic. #------------------ # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: OPP-0138010 #------------------ # Funding_Agency # Funding_Agency_Name: Icelandic Centre of Research, RANNIS # Grant: #040233021, #0070272011, and #100233021 #------------------ # Funding_Agency # Funding_Agency_Name: NSF-ARC # Grant: 0714074 #------------------ # Site_Information # Site_Name: Lake Hvítárvatn # Location: Europe, Iceland, northern North Atlantic region # Country: Iceland # Northernmost_Latitude: 64.613723 # Southernmost_Latitude: 64.613723 # Easternmost_Longitude: -19.843769 # Westernmost_Longitude: -19.843769 # Elevation: 38.33m #------------------ # Data_Collection # Collection_Name: HVT Resampled C:N # Earliest_Year: 9151 # Most_Recent_Year: -6 # Time_Unit: cal yr BP # Core_Length: # Notes: Resampled data (20-year steps)for Hvítárvatn. #------------------ # Chronology: # # # # # # # # #---------------- # Variables # # Data variables follow are preceded by "##" in columns one and two. # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # ##age_calBP Age,,,calendar years BP,,,,,N ##C:N-resamp Carbon/Nitrogen,sediment,,ratio,,paleolimnology,resampled,,N ##C:N-norm Carbon/Nitrogen,sediment,,standard deviation units,,paleolimnology,resampled and normalized,,N #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: # age_calBP C:N-resamp C:N-norm -6 11.3205 2.099 14 11.2109 2.043 34 11.9338 2.411 54 11.9212 2.405 74 13.1278 3.019 94 13.0688 2.989 114 12.5473 2.724 134 12.5271 2.713 154 12.3494 2.623 174 11.9512 2.42 194 11.5584 2.22 214 11.3515 2.114 234 11.5956 2.239 254 11.7358 2.31 274 11.8509 2.369 294 12.4685 2.684 314 11.8554 2.371 334 12.3797 2.638 354 11.8644 2.376 374 11.4424 2.161 394 11.6382 2.261 414 11.5068 2.194 434 11.0958 1.984 454 10.9392 1.904 474 10.4243 1.642 494 9.9829 1.417 514 10.9592 1.915 534 11.9623 2.426 554 10.6489 1.757 574 10.443 1.652 594 10.6158 1.74 614 10.9126 1.891 634 10.7198 1.793 654 9.5561 1.2 674 8.6283 0.727 694 8.8768 0.854 714 8.9147 0.873 734 9.0909 0.963 754 9.6102 1.227 774 8.3556 0.588 794 7.5261 0.166 814 8.3891 0.605 834 7.896 0.354 854 8.4692 0.646 874 9.2785 1.058 894 9.2264 1.032 914 9.2982 1.068 934 8.4646 0.644 954 8.275 0.547 974 8.7103 0.769 994 8.2865 0.553 1014 7.5974 0.202 1034 7.5436 0.175 1054 7.6301 0.219 1074 7.7454 0.277 1094 8.3155 0.568 1114 9.8246 1.337 1134 10.4961 1.679 1154 9.035 0.934 1174 9.9127 1.381 1194 8.4661 0.644 1214 8.7617 0.795 1234 9.4042 1.122 1254 8.5081 0.666 1274 9.2029 1.02 1294 9.0042 0.919 1314 9.2989 1.069 1334 10.0314 1.442 1354 9.9353 1.393 1374 9.6328 1.239 1394 10.7961 1.832 1414 11.3315 2.104 1434 8.2002 0.509 1454 7.7634 0.287 1473 7.4976 0.151 1493 5.7475 -0.74 1513 5.8844 -0.671 1533 6.0753 -0.573 1553 7.2203 0.01 1573 7.4367 0.12 1593 7.2557 0.028 1613 8.3628 0.592 1633 6.9974 -0.104 1653 7.1694 -0.016 1673 7.0791 -0.062 1693 6.2874 -0.465 1713 5.4487 -0.893 1733 5.8071 -0.71 1753 7.4312 0.117 1773 7.4991 0.152 1793 6.373 -0.422 1813 6.2371 -0.491 1833 6.7294 -0.24 1853 6.3925 -0.412 1873 6.442 -0.387 1893 6.3508 -0.433 1913 7.555 0.18 1933 7.0583 -0.073 1953 6.4515 -0.382 1973 6.1832 -0.519 1993 6.4935 -0.36 2013 7.0113 -0.097 2033 6.6169 -0.298 2053 7.3816 0.092 2073 5.5877 -0.822 2093 7.1693 -0.016 2113 7.8006 0.305 2133 6.6053 -0.303 2153 6.2143 -0.503 2173 6.0162 -0.604 2193 6.3638 -0.426 2213 7.7855 0.298 2233 7.0467 -0.079 2253 5.6874 -0.771 2273 6.2802 -0.469 2293 7.8436 0.327 2313 5.2975 -0.97 2333 4.5323 -1.36 2353 4.7878 -1.229 2373 5.1187 -1.061 2393 6.6246 -0.294 2413 5.1172 -1.062 2433 6.4021 -0.407 2453 5.9076 -0.659 2473 5.5251 -0.854 2493 5.037 -1.102 2513 5.8608 -0.683 2533 5.8258 -0.701 2553 5.3846 -0.925 2573 5.1681 -1.036 2593 5.5097 -0.862 2613 5.2677 -0.985 2633 5.3295 -0.953 2653 5.6739 -0.778 2673 5.5798 -0.826 2693 5.8532 -0.687 2713 5.8531 -0.687 2733 6.1691 -0.526 2753 6.5857 -0.313 2773 7.2952 0.048 2793 7.8034 0.307 2813 7.6311 0.219 2833 7.3148 0.058 2853 8.0579 0.437 2873 7.671 0.239 2893 7.9554 0.384 2913 8.6088 0.717 2933 9.3163 1.078 2953 10.6667 1.766 2973 10.019 1.436 2993 6.2688 -0.475 3013 6.1217 -0.55 3033 6.2293 -0.495 3053 5.8454 -0.691 3073 6.1779 -0.521 3093 6.1538 -0.534 3113 5.8522 -0.687 3133 5.8593 -0.684 3153 6.1795 -0.52 3173 5.7332 -0.748 3193 5.9434 -0.641 3213 6.0617 -0.58 3233 6.1134 -0.554 3253 6.0034 -0.61 3273 5.3828 -0.926 3293 5.4602 -0.887 3313 5.4621 -0.886 3333 5.8958 -0.665 3353 5.8433 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-0.764 5492 5.6361 -0.797 5512 6.9499 -0.128 5532 7.0341 -0.085 5552 5.8193 -0.704 5572 5.6801 -0.775 5592 5.0385 -1.102 5612 5.0036 -1.119 5632 4.8225 -1.212 5652 4.8236 -1.211 5672 5.0565 -1.093 5692 5.2345 -1.002 5712 5.6281 -0.801 5732 5.7858 -0.721 5752 5.6715 -0.779 5772 5.5796 -0.826 5792 5.404 -0.916 5812 5.3294 -0.954 5832 5.6108 -0.81 5852 5.766 -0.731 5872 6.0433 -0.59 5892 6.1401 -0.54 5912 5.7407 -0.744 5932 5.989 -0.617 5952 5.8009 -0.713 5972 5.5735 -0.829 5992 6.0114 -0.606 6012 6.5212 -0.346 6032 6.24 -0.49 6052 6.3206 -0.449 6072 6.1948 -0.513 6092 5.8557 -0.685 6112 6.0326 -0.595 6132 6.2893 -0.464 6152 6.3662 -0.425 6172 5.9421 -0.641 6192 5.9106 -0.657 6212 5.7844 -0.722 6232 6.1119 -0.555 6252 6.0865 -0.568 6272 6.4233 -0.396 6292 6.3049 -0.457 6312 6.4093 -0.403 6332 6.7912 -0.209 6352 7.0662 -0.069 6372 7.1157 -0.043 6392 7.4853 0.145 6412 8.5914 0.708 6432 8.647 0.737 6452 7.5845 0.195 6472 7.3253 0.063 6492 7.1372 -0.033 6512 6.949 -0.128 6532 6.7619 -0.224 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-0.758 7631 5.688 -0.771 7651 5.683 -0.773 7671 5.678 -0.776 7691 5.6731 -0.778 7711 5.6398 -0.795 7731 5.5605 -0.836 7751 5.4805 -0.877 7771 5.4005 -0.917 7791 5.3453 -0.945 7811 5.3853 -0.925 7831 5.4347 -0.9 7851 5.4841 -0.875 7871 5.541 -0.846 7891 5.9403 -0.642 7911 6.5258 -0.344 7931 6.747 -0.231 7951 5.6252 -0.803 7971 5.9673 -0.629 7991 8.1872 0.502 8011 6.1328 -0.544 8031 5.9779 -0.623 8051 6.3111 -0.453 8071 6.3235 -0.447 8091 6.6829 -0.264 8111 6.5445 -0.334 8131 7.173 -0.014 8151 8.7177 0.773 8171 7.6104 0.209 8191 8.7461 0.787 8211 10.2157 1.536 8231 10.8713 1.87 8251 8.059 0.437 8271 7.6799 0.244 8291 7.8736 0.343 8311 7.9837 0.399 8331 8.4523 0.637 8351 8.3017 0.561 8371 9.6116 1.228 8391 8.9572 0.895 8411 8.6243 0.725 8431 9.2848 1.062 8451 9.9062 1.378 8471 9.7455 1.296 8491 8.5889 0.707 8511 8.5507 0.688 8531 9.6686 1.257 8551 10.0162 1.434 8571 8.3301 0.575 8591 7.9836 0.399 8611 8.4027 0.612 8631 9.3569 1.098 8651 9.2353 1.036 8671 8.9769 0.905 8691 8.5003 0.662 8711 8.2373 0.528 8731 8.6873 0.757 8751 10.24 1.548 8771 11.0525 1.962 8791 11.0683 1.97 8811 8.5444 0.684 8831 8.2967 0.558 8851 8.4216 0.622 8871 8.4529 0.638 8891 8.3896 0.606 8911 9.0516 0.943 8931 9.8983 1.374 8951 10.7451 1.806 8971 11.5919 2.237 8991 12.4386 2.668 9011 13.1024 3.006 9031 12.5594 2.73 9051 14.246 3.589 9071 14.7328 3.837 9091 12.3608 2.629 9111 9.2711 1.055 9131 9.0744 0.954 9151 9.4006 1.121