Marine Isotope Stage 1

Marine Isotope Stage 1
Name	Marine Isotope Stage 1
Othernames	Holocene interglacial, Current interglacial
Period	Holocene
Time start	11.7 ka BP
Time end	present
Preceding	Marine Isotope Stage 2
Significance	Latest Quaternary interglacial, anthropogenic climate influence

Marine Isotope Stage 1

Marine Isotope Stage 1 is the most recent interglacial interval of the Quaternary, beginning near the end of the last glacial termination and continuing to the present. It is central to studies linking palaeoclimatology, Quaternary geology, and anthropogenic climate change through records from the North Atlantic, Mediterranean, Arctic, Antarctic, and tropical ocean basins. Researchers from institutions such as the University of Cambridge, Smithsonian Institution, Max Planck Society, Scripps Institution of Oceanography, and British Antarctic Survey rely on this stage as a reference frame for late Pleistocene–Holocene environmental reconstructions.

Definition and Nomenclature

The term derives from benthic foraminiferal oxygen isotope stratigraphy developed by teams at the University of Cambridge, Lamont–Doherty Earth Observatory, and the British Geological Survey in the 1970s, formalized alongside chronologies from the International Union for Quaternary Research and the International Commission on Stratigraphy. It is contemporaneous with the chronostratigraphic unit recognized by the International Commission on Stratigraphy as the Holocene; correlations employ markers from the Greenland Ice Core Project, European Project for Ice Coring in Antarctica (EPICA), and North Greenland Ice Core Project (NGRIP). Nomenclature debates have involved palaeoclimatologists at Columbia University, ETH Zurich, and the National Oceanic and Atmospheric Administration regarding subdivisions, epoch boundaries, and ties to the Anthropocene working group of the International Commission on Stratigraphy.

Chronology and Stratigraphy

The stage begins at ~11.7 thousand years before present (ka BP) as constrained by radiometric and varve chronologies produced by teams at Vermont Geological Survey, Caltech, and University of Bern. Stratigraphic markers include the Bølling–Allerød oscillation, the Younger Dryas cessation recorded in cores from the North Atlantic Drift, and tephra layers correlated with eruptions catalogued by the Smithsonian Institution Global Volcanism Program. Age models integrate radiocarbon calibration curves developed by the IntCal Working Group, uranium-thorium chronologies from researchers at University of Oxford, and astrochronology techniques advanced at the University of Arizona and ETH Zurich.

Climate Characteristics and Global Patterns

Stage 1 features a relatively warm, stable climate compared with the preceding glacial, with millennial-scale variability documented in records from Greenland Ice Sheet, Antarctic Peninsula, Barents Sea, Mediterranean Sea, Gulf of Alaska, and the Coral Sea. Patterns include Holocene Thermal Maximum intervals recognized in studies from the University of Bergen, University of British Columbia, and Australian National University, and Neoglacial cooling episodes identified by researchers at Cornell University and University of Wisconsin–Madison. Teleconnections involve shifts in the North Atlantic Oscillation, variations in the El Niño–Southern Oscillation studied by the Plymouth Marine Laboratory, and monsoon fluctuations reconstructed by teams at Peking University and The Ohio State University.

Sea Level and Cryosphere Changes

Global sea-level rise during the early part of Stage 1 is recorded in coral reef terraces documented by scientists at the Smithsonian Tropical Research Institute, James Cook University, and the University of Hawaii. Meltwater pulses correlated with ice-sheet melt were investigated by groups at the US Geological Survey, GEOMAR Helmholtz Centre for Ocean Research Kiel, and Woods Hole Oceanographic Institution. Cryospheric retreat of the Greenland Ice Sheet and reductions in West Antarctic Ice Sheet extent have been analyzed using satellite datasets from NASA and European Space Agency missions, and field programs from Scott Polar Research Institute and Alfred Wegener Institute.

Paleoclimate Proxies and Evidence

Marine isotope signatures are complemented by multi-proxy archives: speleothems from caves studied by University of Innsbruck and Monash University, diatom records from the Alfred Wegener Institute and British Antarctic Survey, pollen assemblages analyzed at Royal Botanic Gardens, Kew and Natural History Museum, London, and stable isotope work from laboratories at Massachusetts Institute of Technology and University of Paris. Foraminiferal assemblages and Mg/Ca ratios analyzed at Netherlands Institute for Sea Research and National Oceanography Centre, Southampton provide sea-surface temperature reconstructions, while biomarkers and alkenone paleothermometry developed by teams at GEOMAR and University of Bristol refine regional patterns.

Regional Expressions and Case Studies

Regional studies illustrate diversity: the Mediterranean Sea shows early-Holocene sapropel formation tied to Nile discharge changes documented by researchers at University of Alexandria and CNRS; the East Asian Monsoon history is revealed in speleothem records from sites studied by Chinese Academy of Sciences teams; Arctic proxies from the Chukchi Sea and Barents Sea are published by University of Tromsø and Polar Research Institute of China; and North American deglaciation chronologies are mapped by the Canadian Ice Service, US Geological Survey, and academic teams at McGill University.

Human and Ecological Impacts

Stage 1 encompasses major human cultural transitions investigated by archaeologists at University of Cambridge, University of Oxford, Max Planck Institute for Evolutionary Anthropology, and Harvard University including Mesolithic and Neolithic dispersals, agricultural origins in regions studied by University of Tübingen and Tel Aviv University, and coastal colonization evident in submerged sites researched by University of Haifa and Flinders University. Ecological responses include forest expansions reconstructed by palynologists at University College Dublin and University of Göttingen, shifts in marine fisheries tracked by University of St Andrews and University of Galway, and megafaunal turnover analyzed by teams at Natural History Museum, London and Smithsonian Institution.

Category:Quaternary