Sigfús J Johnsen

Dados Biográficos

ID5602134
NOMESigfús J Johnsen
PRENOMESSigfús J
SOBRENOMEJohnsen
ASSINATURAJOHNSEN S J
AFILIAÇÕESUniversity of Copenhagen
VERIFICADONão
TOTAL DE OBRAS10
TOTAL DE CITAÇÕES12
TOTAL COMO AUTOR10
TOTAL COMO EDITOR0
PRIMEIRO ANO DE PUBLICAÇÃO1992
ANO MAIS RECENTE DE PUBLICAÇÃO2014
ÍNDICE H1

  • A stratigraphic framework for abrupt climatic changes during the Last Glacial period based on three synchronized Greenland ice-core records

    Open AccessSune O Rasmussen, Matthias Bigler et al.ARTICLEQuaternary Science Reviews2014

    Due to their outstanding resolution and well-constrained chronologies, Greenland ice-core records provide a master record of past climatic changes throughout the Last Interglacial–Glacial cycle in the North Atlantic region. As part of the INTIMATE (INTegration of Ice-core, MArine and TErrestrial records) project, protocols have been proposed to ensure consistent and robust correlation between different records of past climate. A key element of th…

  • High-Resolution Greenland Ice Core Data Show Abrupt Climate Change Happens in Few Years

    Open AccessJørgen Peder Steffensen, K K Andersen et al.ARTICLEScience2008

    The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as r…

  • The 8.2ka event from Greenland ice cores

    Open AccessElizabeth R Thomas, Eric Wolff et al.ARTICLEQuaternary Science Reviews2007

  • The Greenland Ice Core Chronology 2005, 15–42ka. Part 1

    Open AccessK K Andersen, Andreas Svensson et al.ARTICLEQuaternary Science Reviews2006

  • The Greenland Ice Core Chronology 2005, 15–42ka. Part 2

    Open AccessAndreas Svensson, Anders Svensson et al.ARTICLEQuaternary Science Reviews2006

  • Oxygen isotope and palaeotemperature records from six Greenland ice‐core stations

    Open AccessSigfús J Johnsen, Dorthe Dahl‐Jensen et al.ARTICLEJournal of Quaternary Science2001

    Oxygen isotope variations spanning the last glacial cycle and the Holocene derived from ice‐core records for six sites in Greenland (Camp Century, Dye‐3, GRIP, GISP2, Renland and NorthGRIP) show strong similarities. This suggests that the dominant influence on oxygen isotope variations reflected in the ice‐sheet records was regional climatic change. Differences in detail between the records probably reflect the effects of basal deformation in the…

  • The Eem Stable Isotope Record along the GRIP Ice Core and Its Interpretation

    Open AccessSigfús J Johnsen, Henrik B Clausen et al.ARTICLEQuaternary Research1995

    A 3029-m-long deep ice core extending nearly to bedrock has been drilled at the very top of the Greenland ice sheet (Summit) by the Greenland Ice-core Project (GRIP), an international European joint effort organized by the European Science Foundation. The ice core reaches back to 250,000 yr B.P. according to dating based partly on stratigraphic methods and partly on ice-flow modeling. A continuous and detailed stable isotope (δ 18 O) profile alon…

  • Do Greenland Ice Cores Reflect NW European Interglacial Climate Variations?

    Open AccessEiliv Larsen, Hans Petter Sejrup et al.ARTICLEQuaternary Research1995

    The climatic evolution during the Eemian and the Holocene in western Europe is compared with the sea-surface conditions in the Norwegian Sea and with the oxygen-isotope-derived paleotemperature signal in the GRIP and Renland ice cores from Greenland. The records show a warm phase (ca. 3000 yr long) early in the Eemian (substage 5e). This suggests that the Greenland ice sheet, in general, recorded the climate in the region during this time. Rapid …

  • Ash layers from Iceland in the Greenland GRIP ice core correlated with oceanic and land sediments

    Open AccessKarl Grönvold, Níels Óskarsson et al.ARTICLEEarth and Planetary Science Letters1995

    Four previously known ash layers (Ash Zones I and II, Saksunarvatn and the Settlement layer) all originating in Iceland, have been identified in the Central Greenland ice core GRIP. This correlation of the ash between the different environments is achieved by comparison of the chemical composition of glass shards from the ash. This establishes and confirms detailed correlations between the different types of depositional records and the absolute …

  • Radiocarbon Anomalies Observed for Plants Growing in Icelandic Geothermal Waters

    Open AccessÁrný E Sveinbjörnsdóttir, Jan Heinemeier et al.ARTICLERadiocarbon1992Citada por: 12Referências: 8

    We have studied plant remains in thick beds of lacustrine sediments in the upper part of the Markarfljót drainage area in southern Iceland. We collected small samples of plant species from the same horizon and 14 C dated them at the Aarhus AMS Dating Laboratory. Terrestrial plants yielded an age of 9 ka BP, whereas aquaic moss ( Fontinalis antipyretica Hedw.) yielded the surprisingly old 14 C age of 16 ka bp. We believe the age of the terrestrial…