Sediment and ice characteristics at a buried ice-wedge system at Barrow

• Main Authors: Meyer, Hanno, Schirrmeister, Lutz, Andreev, Andrei A, Wagner, Dirk, Hubberten, Hans-Wolfgang, Yoshikawa, Kenji, Bobrov, Anatoly A, Wetterich, Sebastian, Opel, Thomas, Kandiano, Evgenia S, Brown, Jerry
• Format: Dataset
• Language: English
• Published: PANGAEA 2010
• Subjects: AK-Land_2004_Fairbanks_Barrow; AK-Land_2004_Fairbanks_Barrow_all; AK-Land_2006_Fairbanks_Barrow; AK-Land_2006_Fairbanks_Barrow_all; Alaska 2004; Alaska 2006; AWI; AWI Arctic Land Expedition; Barrow_transect; Barrow; Alaska; USA; International Polar Year (2007-2008); IPY; MON; Monitoring; MULT; Multiple investigations; Arctic; Ice; International Polar Year; permafrost; wedge*
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.816847; https://doi.org/10.1594/PANGAEA.816847

Barrow, the northernmost point in Alaska, is one of the most intensively studied areas in the Arctic. However, paleoenvironmental evidence is limited for northern Alaska for the Lateglacial-Holocene transition. For a regional paleoenvironmental reconstruction, we investigated a permafrost ice-wedge tunnel near Barrow, Alaska. The studied site was first excavated in the early 1960s and intercepts a buried ice-wedge system at 3-6 m depth below the surface. A multi-methodological approach was applied to this buried ice-wedge system and the enclosing sediments, which in their combination, give new insight into the Late Quaternary environmental and climate history. Results of geochronological, sedimentological, cryolithological, paleoecological, isotope geochemical and microbiological studies reflect different stages of mid to late Wisconsin (MW to LW), Allerod (AD), Younger Dryas (YD), Preboreal (PB), and Late Holocene paleoenvironmental evolution. The LW age of the site is indicated by AMS dates in the surrounding sediments of 21.7 kyr BP at the lateral contact of the ice-wedge system as well as 39.5 kyr BP below the ice-wedge system. It is only recently that in this region, stable isotope techniques have been employed, i.e. to characterize different types of ground ice. The stable isotope record (oxygen: d18O; hydrogen: dD) of two intersecting ice wedges suggests different phases of the northern Alaskan climate history from AD to PB, with radiocarbon dates from 12.4 to 9.9 kyr BP (ranging from 14.8 to 10.6 kyr cal BP). Stable isotope geochemistry of ice wedges reveals winter temperature variations of the Lateglacial-Holocene transition including a prominent YD cold period, clearly separated from the warmer AD and PB phases. YD is only weakly developed in summer temperature indicators (such as pollen) for the northern Alaska area, and by consequence, the YD cold stadial was here especially related to the winter season. This highlights that the combination of winter and summer indicators comprehensively describes ...