Istorvet Ice Cap, East Greenland Late Holocene Radiocarbon Ages ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: Please cite original reference when using these data, plus the data file URL and date accessed. NAME OF DATA SET: Istorvet Ice Cap, East Greenland Late Holocene Radiocarbon Ages LAST UPDATE: 8/2012 (Original receipt by WDC Paleo) CONTRIBUTORS: Lowell, T.V., B.L. Hall, M.A. Kelly, O. Bennike, A.R. Lusas, W. Honsaker, C.A. Smith, L.B. Levy, S. Travis, and G.H. Denton IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2012-128 WDC PALEO CONTRIBUTION SERIES CITATION: Lowell, T.V., et al. 2012. Istorvet Ice Cap, East Greenland Late Holocene Radiocarbon Ages. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2012-128. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Lowell, T.V., B.L. Hall, M.A. Kelly, O. Bennike, A.R. Lusas, W. Honsaker, C.A. Smith, L.B. Levy, S. Travis, and G.H. Denton. 2012. Late Holocene expansion of Istorvet ice cap, Liverpool Land, east Greenland. Quaternary Science Reviews, 63, 128-140, ISSN 0277-3791. ABSTRACT: The Greenland Ice Sheet currently is undergoing dynamic changes that have global implications. Understanding the climate conditions that influence these changes is important for predicting the future behavior of the cryosphere. Small ice caps in Greenland that are independent from, but adjacent to, the Greenland Ice Sheet (hereinafter called "local ice caps") can be used as sensitive indicators of the climatic conditions at the ice sheet margin. We reconstruct the recent fluctuations of a local ice cap in east Greenland known as Istorvet ice cap and use these to interpret Holocene climatic conditions. We base the ice cap extent reconstruction on radiocarbon dating of relic plant remains, 10Be dating of boulders and analyses of sediment cores from lakes. Deglaciation subsequent to the last ice age reached the present ice cap extent by ~10,500 cal yr BP. Subsequent to this time, the ice cap advanced to its maximum Holocene extent during the last millennium. Subfossil plants exposed by recent ice retreat indicate that the ice cap was smaller than at present from AD 200 to 1025. Sediments from a threshold lake indicate that the ice cap was within 365 m of its maximum extent by ~AD 1150. The ice cap reached a maximum thereafter and remained at this extent until at least AD 1700. Given that the climatic conditions that influenced Istorvet ice cap also influenced the Greenland Ice Sheet margin, we suggest that the ice sheet likely also reached its Holocene maximum during the last millennium. Comparison of the Istorvet ice cap fluctuations with Holocene glacier extents in southern middle to high latitude locations suggests a possible out-of-phase relationship. This pattern supports the hypothesis for bi-polar oceanic or atmospheric circulation during the Holocene that produces an asynchronous response between the Northern and Southern hemispheres. GEOGRAPHIC REGION: East Greenland PERIOD OF RECORD: ~1590 - 115 YrBP FUNDING SOURCES: US National Science Foundation, awards ARC-0909285, ARC-090808, and ARC-0909270. DATA FILE URLS: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/radiocarbon/istorvet2012c14.txt ftp://ftp.ncdc.noaa.gov/pub/data/paleo/radiocarbon/istorvet2012c14.xls DESCRIPTION: Radiocarbon ages from subfossil plants collected on the western side of the Istorvet ice cap, Liverpool Land, East Greenland. These radiocarbon ages represent former plants growing at near the current margin of the ice cap and thus represent the last time the ice cap was the same size or smaller than present. Data include location, field label, dated material, NOSAMS number, d13C, Age, error, start AD, End AD, Relative area, Other Taxa, latitude, longitude, and elevation. Istorvet Site Locations: 70.87 to 71.0°N, 21.17 to 22.28°W, 520 to 835m elev. DATA: Data include location, field label, dated material, NOSAMS number, d13C, Age, error, start AD, End AD, Relative area, Other Taxa, latitude, longitude, elevation Lowell et al. 2012 Table 1 Istorvet radiocarbon data Location Field Label Dated Material NOSAMS d13C Age Error Start End Relative Latitude Longitude Elevation Other Taxa Number ‰ AD AD Area N W masl Southern Istorvet Sites West Margin G-06-164C Saxifraga oppositifolia OS-59667 -27.69 1090 35 942 991 0.65 70.884 22.25 520 Hepaticopsida indet., Bryopsida indet., Poaceae indet. 897 922 0.34 G-06-164D Saxifraga oppositifolia OS-59679 -20.57 1140 25 916 967 0.74 70.883 22.25 522 Ditrichum sp. 883 902 0.26 G-06-164I Dryas octopetala OS-59680 -27.04 1130 25 916 967 0.81 70.883 -22.25 518 Cenococcum geophilum, Bryopsida indet., Polytrichum sp., Salix arctica, Saxifraga caespitosa, Brachycera indet., Dicrostonyx torquatustica 890 901 0.19 TL-06-289A Dryas octopetala OS-59636 -26.39 1090 30 945 989 0.65 70.887 -22.249 453 Cenococcum geophilum, Bryopsida indet., Salix arctica, Salix arctica, Carex sp., Poaceae indet 898 920 0.35 TL-06-289C Dryas octopetala OS-59533 -26.87 1190 30 807 882 0.87 70.887 -22.249 453 Carex sp. 781 791 0.13 TL-06-289D Dryas octopetala OS-59637 -25.75 1170 30 807 894 0.9 70.887 -22.249 453 Bryopsida indet., Carex sp., Dicrostonyx torquatus 781 791 0.1 TL-06-289E Dryas octopetala OS-59703 -27.04 1040 30 986 1021 1 70.887 -22.249 453 Cenococcum geophilum, Bryopsida indet., Polytrichum sp., Carex sp., Poaceae indet. TL-06-289F Dryas octopetala OS-64826 -26.24 1210 35 761 894 0.83 70.887 -22.249 453 Cenococcum geophilum, Brachycera indet. 689 752 0.17 Middle Nunatak TL-06-291C Salix arctica OS-59529 -25.6 1050 30 978 1020 1 70.888 -22.205 607 TL-06-291D Salix arctica OS-59579 -26.75 1090 25 949 988 0.65 70.888 -22.205 607 Cenococcum geophilum, Hepaticopsida indet., Ditrichum sp., Distichium sp., Brachycera indet., Cassiope tetragona, Dryas octopetala 899 919 0.35 TL-06-291E Salix arctica OS-64834 -27.24 1090 30 945 989 0.65 70.888 -22.205 607 898 920 0.35 TL-06-293 Salix arctica OS-59580 -26.3 1180 30 772 900 0.9 70.888 -22.201 630 Bryopsida indet. 918 963 0.1 High Nunatak TL-06-294A Salix arctica OS-59581 -24.19 1590 25 426 43 0.19 70.887 -22.185 719 Polytrichum sp., Cassiope tetragona 450 462 0.14 483 533 0.65 TL-06-294B Cassiope tetragona OS-59582 -25.71 1380 30 639 667 1 70.887 -22.185 719 Bryopsida indet., Polytrichum sp., Salix arctica TL-06-294C Salix arctica OS-64832 -24.19 1220 25 772 830 0.67 70.887 -22.185 719 Bryopsida indet. 836 868 0.33 TL-06-294E Cassiope tetragona OS-64833 -24.69 1400 30 622 659 1 70.887 -22.185 719 Bryopsida indet., Polytrichum sp., 606 673 0.67 485 534 0.17 Istor-13 Cassiope tetragona OS-85638 -26.16 1270 50 668 779 0.99 70.886 22.176 735 Salix arctica Istor-15 Cassiope tetragona OS-85633 -24.24 1180 50 775 897 0.95 70.886 22.176 735 Salix arctica Istor-17 Cassiope tetragona OS-85627 -26.25 1150 60 804 973 0.96 70.886 22.176 735 Salix arctica Istor-19 Cassiope tetragona OS-85485 -25.65 1250 50 678 784 0.83 70.886 22.176 735 Salix arctica 786 827 0.12 Istor-22 Cassiope tetragona OS-85486 -25* 1380 50 614 673 1 70.886 22.176 735 Salix arctica Highest Nunatak Istor-9 Salix arctica OS-85637 -26.46 1460 60 554 647 1 70.881 22.153 835 Istor-11 Salix arctica OS-85628 -25.55 1660 50 326 433 0.97 70.881 22.153 835 North Margin Istor-23 Salix arctica OS-85487 -26.21 1410 25 601 661 1 70.905 22.178 682 Istor-24 Cassiope tetragona OS-85488 -21.95 1220 25 765 886 0.83 70.905 22.178 682 708 747 0.16 Istor-26 Salix arctica OS-85489 -27.25 1530 30 502 600 0.65 70.905 22.178 682 432 497 0.35 Istor-27 Salix arctica OS-85490 -27.09 1710 25 325 384 0.74 70.905 22.178 682 260 281 0.26 Northern Istorvet Sites Lake Margin SS-10-24 Salix arctica OS-85791 -26.85 280 70 1491 1602 0.59 70.977 22.252 580 1613 1667 0.37 SS-10-27 Salix arctica in till OS-85631 -26.19 115 50 1803 1937 0.7 70.977 22.248 533 1681 1738 0.29 SS-10-31 Bryopsida indet. OS-85792 -28.14 220 50 1762 1802 0.44 70.977 22.248 533 1644 1681 0.43 1937 1951 0.1 SS-10-34 Salix arctica OS-85793 -24.28 200 60 1730 1809 0.56 70.977 22.249 532 1647 1688 0.27 1926 1952 0.17 SS-10-36 Salix arctica OS-85794 -24.18 205 60 1732 1808 0.54 70.977 22.249 532 1646 1685 0.29 1928 1952 0.16 SS-10-37 Salix arctica OS-85795 -24.18 130 50 1800 1893 0.46 70.976 22.248 525 1677 1766 0.36 1906 1940 0.16 SS-10-39 Salix arctica OS-85796 -25.2 260 50 1630 1668 0.68 70.976 22.248 525 1523 1560 0.19 1781 1797 0.11 SS-10-41 Cassiope tetragona OS-85922 -27.63 125 50 1800 1894 0.5 70.976 22.248 525 1680 1764 0.34 1904 1939 0.16 SS-10-42 Cassiope tetragona OS-85902 -28.32 145 60 1797 1891 0.35 70.977 22.249 535 1717 1781 0.3 1909 1948 0.17 1668 1710 0.17 1668 1710 0.17 SS-10-43 Bryopsida indet. OS-85925 -24.76 125 50 1800 1894 0.5 70.978 22.249 538 1680 1764 0.34 1904 1939 0.16 SS-10-44 organic mat below till OS-85797 -24.18 120 70 1677 1765 0.34 70.978 22.249 542 1800 1940 0.64 1677 1765 0.34 SS-10-45 Salix arctica OS-85798 -26.91 175 60 1725 1814 0.55 70.978 22.249 543 1917 1952 0.2 1657 1696 0.19 SS-10-47 Salix arctica OS-85895 -26.16 225 50 1642 1681 0.48 70.977 22.25 531 Cassiope tetragona 1763 1802 0.42 Eastern Margin COL-26 Salix arctica OS-85787 -28.47 295 25 1512 1601 0.68 70.991 22.26 558 1616 1655 0.3 70.991 22.26 558 COL-28 Salix arctica OS-85788 -28.47 240 25 1447 1524 0.65 70.991 22.259 577 1776 1800 0.3 70.991 22.259 577 COL-30 Salix arctica OS-85789 -30.14 375 25 1447 1524 0.65 1570 1631 0.33 COL-32 Cassiope tetragona OS-85900 -25* 225 30 1736 1805 0.45 70.978 22.172 647 1641 1683 0.44 Northwest Margin 70.978 22.172 647 SS-10-48 Salix arctica OS-85874 -26.13 445 25 1433 1452 1 SS-10-49 moss OS-86036 -26.96 235 35 1641 1673 0.55 1733 1807 0.38 70.978 22.172 647 1929 1952 0.1 SS-10-54A Salix arctica OS-86015 -28.65 525 25 1406 1429 1 SS-10-54B moss OS-86075 -26.1 470 30 1425 1445 1 70.969 22.153 732 Dated Samples Recovered From Cores Bone Lake BONE-01-T1_35cm OS-86758 -25.57 895 25 1043 1106 0.41 70.888 22.267 433 1118 1186 0.59 Bone Lake BONE-4A-1L-1_31cm OS-86722 -25.6 880 25 1045 1094 0.23 1147 1219 0.69 70.888 22.267 435 Emerald Lake EMRD-1A-4L-1_55cm OS-86931 -13.73 8510 180 9264 9737 1 70.884 22.276 418 9508 Snowbank Lake SNWB-1B-3L-1_33cm OS-88278 9330 40 10495 10587 0.94 70.886 22.279 449 10543 Snoopy Lake SPY-1A-1N-4 OS-86674 -24.4 8740 90 9583 9828 0.83 70.978 22.294 450 9761 * assumed Note: ages >2000 14C given in cal yr BP. For these the median probability is also given.