North Icelandic Shelf 1350 Year Molusc Radiocarbon Data ----------------------------------------------------------------------- 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: North Icelandic Shelf 1350 Year Molusc Radiocarbon Data LAST UPDATE: 6/2012 (Original receipt by WDC Paleo) CONTRIBUTORS: Wanamaker, A.D., P.G. Butler, J.D. Scourse, J. Heinemeier, J. Eiríksson, K.L. Knudsen, and C.A. Richardson. IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2012-084 WDC PALEO CONTRIBUTION SERIES CITATION: Wanamaker, A.D., et al. 2012. North Icelandic Shelf 1350 Year Molusc Radiocarbon Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2012-084. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Wanamaker, A.D., P.G. Butler, J.D. Scourse, J. Heinemeier, J. Eiríksson, K.L. Knudsen, and C.A. Richardson. 2012. Surface changes in the North Atlantic meridional overturning circulation during the last millennium. Nature Communications, Published 12 Jun 2012. DOI: 10.1038/ncomms1901 ABSTRACT: Despite numerous investigations, the dynamical origins of the Medieval Climate Anomaly and the Little Ice Age remain uncertain. A major unresolved issue relating to internal climate dynamics is the mode and tempo of Atlantic meridional overturning circulation variability, and the significance of decadal-to-centennial scale changes in Atlantic meridional overturning circulation strength in regulating the climate of the last millennium. Here we use the time-constrained high-resolution local radiocarbon reservoir age offset derived from an absolutely dated annually resolved shell chronology spanning the past 1,350 years, to reconstruct changes in surface ocean circulation and climate. The water mass tracer data presented here from the North Icelandic shelf, combined with previously published data from the Arctic and subtropical Atlantic, show that surface Atlantic meridional overturning circulation dynamics likely amplified the relatively warm conditions during the Medieval Climate Anomaly and the relatively cool conditions during the Little Ice Age within the North Atlantic sector. GEOGRAPHIC REGION: North Atlantic PERIOD OF RECORD: 675 - 1950 AD FUNDING SOURCES: EU funded Millennium project (017008) DATA FILE URLS: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wanamaker2012/wanamaker2012.txt ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wanamaker2012/wanamaker2012.xls DESCRIPTION: Radiocarbon content of shells of the long-lived marine bivalve Arctica islandica collected on the North Icelandic shelf. The shells were absolutely dated using crossdating techniques derived from dendrochronology, and provide a 1350-year record of water mass migration and strength of the Atlantic meridional overturning circulation. Shells were collected near the island of Grimsey, North Icelandic Shelf, at a water depth of 81-83 m from the RV Bjarni Saemundsson (Cruise No. B05-2006, trawl B05AD03). Trawl B05AD03: 66°31.59'N, 18°11.74'W, ~82m water depth. DATA: Wanamaker et al. 2012 Supplementary Data 1 Isotope per mil VPDB Sample Integration (± yrs) Laboratory SampleID Site ScleroAge 14Cage 14C Marine09 Marine09 Sample DR DR d13C d18O Code YearAD YrBP Err± 14CageBP Err± Int.Yrs± Err± ±0.05 <±0.10 AAR-12978 061664_1 Iceland 675 1759 37 1720 26 < 5 39 45.2 2.62 2.83 AAR-12979 061664_2 Iceland 705 1703 27 1670 26 < 5 33 37.5 2.49 2.26 AAR-12980 061664_3 Iceland 730 1581 40 1641 26 < 5 -60 47.7 1.85 2.12 AAR-12981 061664_4 Iceland 760 1562 33 1627 26 < 5 -65 42.0 2.2 2.56 AAR-12982 061664_5 Iceland 795 1704 28 1583 25 < 5 121 37.5 2.36 2.13 AAR-12983 061664_6 Iceland 830 1632 27 1555 26 < 5 77 37.5 2.17 2.58 AAR-12984 061664_7 Iceland 870 1531 28 1534 26 < 5 -3 38.2 2.16 2.44 AAR-12985 061664_8 Iceland 910 1540 29 1485 26 < 5 55 38.9 2.5 2.44 AAR-12986 061664_9 Iceland 920 1484 28 1475 26 < 5 9 38.2 2.4 2.01 AAR-12987 061664_10 Iceland 940 1498 31 1471 27 10 27 41.1 2.43 2.29 AAR-12988 06312_1 Iceland 970 1542 28 1451 25 < 5 91 37.5 2.32 2.59 AAR-11535 061664 Iceland 990 1421 50 1430 25 10 -9 55.9 2.48 2.42 AAR-12989 06312_2 Iceland 1000 1526 41 1415 25 < 5 111 48.0 2.04 2.29 AAR-12990 06312_3 Iceland 1025 1473 28 1388 25 < 5 85 37.5 1.94 2.58 AAR-12991 06312_4 Iceland 1040 1482 26 1358 25 < 5 124 36.1 2.13 3.04 AAR-12992 06312_5 Iceland 1080 1416 35 1301 25 < 5 115 43.0 2.23 2.35 AAR-12993 06312_6 Iceland 1120 1410 27 1289 25 < 5 121 36.8 2.48 2.74 AAR-12994 06312_7 Iceland 1170 1341 26 1248 25 < 5 93 36.1 2.56 2.76 AAR-12995 06312_8 Iceland 1210 1307 36 1213 26 10 94 44.4 2.32 2.51 AAR-11518 061312 Iceland 1216 1245 33 1207 25 10 38 41.4 1.87 2.43 AAR-11536 061682 Iceland 1376 1067 35 1000 25 10 67 43.0 2.08 2.23 AAR-11526 061436 Iceland 1378 1125 32 1000 25 10 125 40.6 2.07 2.9 AAR-11528 061495 Iceland 1401 1137 32 976 25 10 161 40.6 2.32 2.2 AAR-11524 061402 Iceland 1424 1002 29 935 25 10 67 38.3 1.7 2.54 AAR-11522 061347 Iceland 1490 889 31 811 25 10 78 39.8 1.93 2.67 AAR-11784 061294 Iceland 1505 951 27 790 24 < 5 161 36.1 2.68 2.29 AAR-11521 061330 Iceland 1549 874 30 736 23 10 138 37.8 1.81 2.45 AAR-11519 061315 Iceland 1569 863 45 723 23 10 140 50.5 1.93 2.21 AAR-11537 061683 Iceland 1698 719 30 580 23 10 139 37.8 1.63 2.48 AAR-11520 061323 Iceland 1784 617 37 534 23 10 83 43.6 1.7 2.66 AAR-12999 061297_1 Iceland 1790 673 27 541 23 < 5 132 35.5 3.14 3.19 AAR-11538 061702 Iceland 1810 644 31 527 23 10 117 38.6 2.34 2.85 AAR-13000 061297_2 Iceland 1840 640 28 490 23 < 5 150 36.2 2.19 2.37 AAR-13001 061297_3 Iceland 1855 661 27 483 23 < 5 178 35.5 1.76 2.59 AAR-13002 061297_4 Iceland 1880 615 39 473 23 10 142 45.3 1.93 2.5 AAR-11523 061364 Iceland 1895 455 29 460 23 10 -5 37.0 2.17 2.35 AAR-12996 061257u Iceland 1900 561 28 454 23 < 5 107 36.2 2.96 2.58 AAR-13003 061297_5 Iceland 1915 648 34 448 23 < 5 200 41.0 1.86 1.65 AAR-12282 061273-1 Iceland 1935 579 45 457 23 < 5 122 50.5 1.39 2.01 AAR-12283 061273-2 Iceland 1945 558 23 464 23 < 5 94 32.5 2.18 2.23 AAR-12284 061280-1 Iceland 1950 447 43 469 24 < 5 -22 49.2 2.05 2.36