Thomas M. Cronin
Laura Gemery
Lloyd D Keigwin
Christof Pearce
Martin Jakobsson
Helen K Coxall
Emily A Wei
Neal W. Driscoll
Julia Lynn Seidenstein
2018
<p><span>Calcareous microfossil assemblages in late Holocene sediments from the western Arctic continental shelf provide an important baseline for evaluating the impacts of today’s changing Arctic oceanography. This study compares </span><sup>14</sup><span>C-dated late Holocene microfaunal assemblages of sediment cores SWERUS-L2-2-PC1, 2-MC4 and 2-KL1 (57 mwd), which record the last 4200 years in the Herald Canyon (Chukchi Sea shelf), and HLY1302-JPC-32, GGC-30, MC-29 (60 mwd), which record the last 3000 years in the Beaufort Sea shelf off the coast of Canada. Foraminiferal and ostracode assemblages are typical of Arctic continental shelf environments with annual sea-ice cover and show relatively small changes in terms of variability of dominant species. Important microfaunal changes in the Beaufort site include a spike in </span><i>Spiroplectammina biformis</i><span> coinciding with a decrease in </span><i>Cassidulina reniforme</i><span> in the last few centuries suggesting an increase of Pacific Water influence and decreased sea-ice. There is low-amplitude centennial-scale variability in proportions of benthic foraminiferal species, such as </span><i>C. reniforme</i><span>. In addition to these species, </span><i>Cassidulina teretis s.l., Elphidium excavatum clavatum</i><span> and </span><i>Stainforthia feylingi</i><span> are also common at this site. At the Herald Canyon site in the last few centuries, </span><i>C. reniforme</i><span> peaks around 150 years BP and then decreases while </span><i>Spiroplectammina earlandi</i><span> spikes and </span><i>Acanthocythereis dunelmensis</i><span> decreases also suggesting an increase in Pacific Water influence and decreased sea-ice at this site. This site also includes </span><i>Buccella</i><span> spp. and </span><i>Elphidium excavatum clavatum</i><span>. Differences in benthic foraminifera and ostracode species dominance between the two sites may be due to a greater influence of Pacific Water in the Chukchi shelf, compared to the more distal Beaufort shelf, which is also affected by the Beaufort Gyre and the Mackenzie River.</span></p>
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10.1007/s41063-018-0058-7
en
Springer Link
Late Holocene paleoceanography in the Chukchi and Beaufort Seas, Arctic Ocean, based on benthic foraminifera and ostracodes
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