SEASONAL TEMPERATURES IN THE ARCTIC DURING THE LATE PLEISTOCENE DETERMINED USING HIGH-RESOLUTION OXYGEN ISOTOPE MEASUREMENTS ACROSS FOSSIL WOOD

2017 ◽  
Author(s):  
Collin Scott Moore ◽  
◽  
Brian A. Schubert
2019 ◽  
Vol 487 (1) ◽  
pp. 823-826 ◽  
Author(s):  
Yu. K. Vasil’chuk ◽  
N. A. Budantseva ◽  
A. C. Vasil’chuk

Oxygen isotope measurements have been made in foraminifera from over 60 deep-sea sediment cores. Taken together with the oxygen isotope measurements published by Emiliani from Caribbean and Equatorial Atlantic cores, this comprises a unique body of stratigraphic data covering most of the important areas of calcareous sediment over the whole world ocean. The oxygen isotopic composition of foraminifera from cores of Late Pleistocene sediment varies in a similar manner in nearly all areas; the variations reflect changes in the oxygen isotopic composition of the ocean. The oceans are mixed in about 1 ka so that ocean isotopic changes, resulting from fluctuations in the quantity of ice stored on the continents, must have occurred almost synchronously in all regions. Thus the oxygen isotope record provides an excellent means of stratigraphic correlation. Cores accumulated at rates of over about 5 cm/ka provide records of oxygen isotopic composition change that are almost unaffected by post-depositional mixing of the sediment. Thus they preserve a detailed record of the advance and retreat of the ice masses in the northern hemisphere, and provide a unique source of information for the study of ice-sheet dynamics.


Oecologia ◽  
2004 ◽  
Vol 141 (3) ◽  
pp. 477-488 ◽  
Author(s):  
Keith A. Hobson ◽  
Gabriel J. Bowen ◽  
Leonard I. Wassenaar ◽  
Yves Ferrand ◽  
Hervé Lormee

2021 ◽  
Author(s):  
Elisie Kåresdotter ◽  
Zahra Kalantari

<p>Wetlands as large-scale nature-based solutions (NBS) provide multiple ecosystem services of local, regional, and global importance. Knowledge concerning location and vulnerability of wetlands, specifically in the Arctic, is vital to understand and assess the current status and future potential changes in the Arctic. Using available high-resolution wetland databases together with datasets on soil wetness and soil types, we created the first high-resolution map with full coverage of Arctic wetlands. Arctic wetlands' vulnerability is assessed for the years 2050, 2075, and 2100 by utilizing datasets of permafrost extent and projected mean annual average temperature from HadGEM2-ES climate model outputs for three change scenarios (RCP2.6, 4.5, and 8.5). With approximately 25% of Arctic landmass covered with wetlands and 99% being in permafrost areas, Arctic wetlands are highly vulnerable to changes in all scenarios, apart from RCP2.6 where wetlands remain largely stable. Climate change threatens Arctic wetlands and can impact wetland functions and services. These changes can adversely affect the multiple services this sort of NBS can provide in terms of great social, economic, and environmental benefits to human beings. Consequently, negative changes in Arctic wetland ecosystems can escalate land-use conflicts resulting from natural capital exploitation when new areas become more accessible for use. Limiting changes to Arctic wetlands can help maintain their ecosystem services and limit societal challenges arising from thawing permafrost wetlands, especially for indigenous populations dependent on their ecosystem services. This study highlights areas subject to changes and provides useful information to better plan for a sustainable and social-ecological resilient Arctic.</p><p>Keywords: Arctic wetlands, permafrost thaw, regime shift vulnerability, climate projection</p>


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