Features of Mineral Composition of Deposits from the Shelf of East Part of the Laptev Sea and the East-Siberian Sea

We present the initial data on the distribution of benthic foraminifera (BF) on East Siberian Sea shelf. Previous researchers analyzed BF in the sediment cores from the continental slope and basin areas of the East Siberian Sea (Wollenburg et al., 2000; Mackensen et al, 2014; Barrientos et al, 2018) but not from central shelf. Last year we received boxcorer samples of bottom sediments from the shelf of the East Siberian Sea and the Laptev Sea during the 78th cruise of research vessel Akademik Mstislav Keldysh (September-October 2019). We examined the species composition of BF assemblages of Rose Bengal-stained surface samples from 2 stations in the East Siberian Sea and 7 stations in the Laptev Sea, and compared this data set with an existing data set along the East Siberian Sea and the Laptev Sea.Recent studies (Shakhova et al, 2007, 2009, 2015; Nicolsky et al, 2009) state that the East Siberian Sea is one of the largest sources of methane emission into the atmosphere due to degradation of permafrost, ice complex retreat and decaying gas hydrates deposits. Perhaps this has an impact on the species composition of the BF assemblages and the morphological changes and defects of their shells, which we have identified. Samples from active methane seeps of the Laptev Sea have been studied to identify the relationship between methane emission and the reaction of benthic foraminifera. This data have been compared with &#8220;background&#8221; (i.e. non-venting, without any methane seeps activity) stations of the Laptev Sea and the East Siberian Sea.The identified features require further detailed study.

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Carbon mineralization in Laptev and East Siberian sea shelf and slope sediment

Biogeosciences ◽

10.5194/bg-15-471-2018 ◽

2018 ◽

Vol 15 (2) ◽

pp. 471-490 ◽

Cited By ~ 7

Author(s):

Volker Brüchert ◽

Lisa Bröder ◽

Joanna E. Sawicka ◽

Tommaso Tesi ◽

Samantha P. Joye ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Carbon Mineralization ◽

Laptev Sea ◽

East Siberian Sea ◽

Degradation Rates ◽

Siberian Arctic ◽

Sediment Carbon ◽

The Laptev Sea ◽

Carbon Contribution

Abstract. The Siberian Arctic Sea shelf and slope is a key region for the degradation of terrestrial organic material transported from the organic-carbon-rich permafrost regions of Siberia. We report on sediment carbon mineralization rates based on O2 microelectrode profiling; intact sediment core incubations; 35S-sulfate tracer experiments; pore-water dissolved inorganic carbon (DIC); δ13CDIC; and iron, manganese, and ammonium concentrations from 20 shelf and slope stations. This data set provides a spatial overview of sediment carbon mineralization rates and pathways over large parts of the outer Laptev and East Siberian Arctic shelf and slope and allows us to assess degradation rates and efficiency of carbon burial in these sediments. Rates of oxygen uptake and iron and manganese reduction were comparable to temperate shelf and slope environments, but bacterial sulfate reduction rates were comparatively low. In the topmost 50 cm of sediment, aerobic carbon mineralization dominated degradation and comprised on average 84 % of the depth-integrated carbon mineralization. Oxygen uptake rates and anaerobic carbon mineralization rates were higher in the eastern East Siberian Sea shelf compared to the Laptev Sea shelf. DIC ∕ NH4+ ratios in pore waters and the stable carbon isotope composition of remineralized DIC indicated that the degraded organic matter on the Siberian shelf and slope was a mixture of marine and terrestrial organic matter. Based on dual end-member calculations, the terrestrial organic carbon contribution varied between 32 and 36 %, with a higher contribution in the Laptev Sea than in the East Siberian Sea. Extrapolation of the measured degradation rates using isotope end-member apportionment over the outer shelf of the Laptev and East Siberian seas suggests that about 16 Tg C yr−1 is respired in the outer shelf seafloor sediment. Of the organic matter buried below the oxygen penetration depth, between 0.6 and 1.3 Tg C yr−1 is degraded by anaerobic processes, with a terrestrial organic carbon contribution ranging between 0.3 and 0.5 Tg yr−1.

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Bryozoa of the Laptev and East Siberian seas: modern research

Transaction Kola Science Cetnre ◽

10.37614/2307-5252.2021.3.9.008 ◽

2021 ◽

Vol 12 (3-2021) ◽

pp. 59-67

Author(s):

O.Yu. Evseeva ◽

Keyword(s):

Climate Change ◽

Comparative Analysis ◽

20Th Century ◽

21St Century ◽

Laptev Sea ◽

Arctic Species ◽

East Siberian Sea ◽

The Laptev Sea

The new data about bryozoan fauna of the Siberian seas (Laptev Sea and East Siberian Sea) are obtained. 48 species of Bryozoa were identified in the samples, collected in the MMBI RAS expedition (2014) at 50 stations: 45 – in the Laptev Sea and 16 – in the East Siberian Sea. The taxonomic and biogeographic composition, the features of distribution of Bryozoa are analyzed. A comparative analysis of the studies of the end of the 20th century (1986, 1987 and 1993–1998) based on literature data is carried out (Gontar, 1990, 1994, 2004, 2015а,б, 2016). There was a significant increase 60 in the share of boreal-arctic species due to a significant decrease of arctic species (by almost a third), which probably reflects the climate change towards warming , observed at the beginning of the 21st century.

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THE STRUCTURAL STYLE OF SEDIMENTARY BASINS ON THE SHELVES OF THE LAPTEV SEA AND WESTERN EAST SIBERIAN SEA, SIBERIAN ARCTIC

Journal of Petroleum Geology ◽

10.1111/j.1747-5457.2005.tb00083.x ◽

2005 ◽

Vol 28 (3) ◽

pp. 269-286 ◽

Cited By ~ 20

Author(s):

D. Franke ◽

K. Hinz

Keyword(s):

Sedimentary Basins ◽

Laptev Sea ◽

Structural Style ◽

East Siberian Sea ◽

Siberian Arctic ◽

The Laptev Sea

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Contrasting regimes for organic matter degradation in the East Siberian Sea and the Laptev Sea assessed through microbial incubations and molecular markers

Marine Chemistry ◽

10.1016/j.marchem.2014.12.005 ◽

2015 ◽

Vol 170 ◽

pp. 11-22 ◽

Cited By ~ 15

Author(s):

E.S. Karlsson ◽

V. Brüchert ◽

T. Tesi ◽

A. Charkin ◽

O. Dudarev ◽

...

Keyword(s):

Organic Matter ◽

Molecular Markers ◽

Laptev Sea ◽

Organic Matter Degradation ◽

East Siberian Sea ◽

The Laptev Sea

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Shipborne eddy covariance observations of methane fluxes constrain Arctic sea emissions

Science Advances ◽

10.1126/sciadv.aay7934 ◽

2020 ◽

Vol 6 (5) ◽

pp. eaay7934 ◽

Cited By ~ 5

Author(s):

Brett F. Thornton ◽

John Prytherch ◽

Kristian Andersson ◽

Ian M. Brooks ◽

Dominic Salisbury ◽

...

Keyword(s):

Arctic Ocean ◽

Eddy Covariance ◽

Noise Level ◽

Laptev Sea ◽

East Siberian Sea ◽

Arctic Sea ◽

Emission Estimate ◽

Methane Fluxes ◽

The Laptev Sea

We demonstrate direct eddy covariance (EC) observations of methane (CH4) fluxes between the sea and atmosphere from an icebreaker in the eastern Arctic Ocean. EC-derived CH4 emissions averaged 4.58, 1.74, and 0.14 mg m−2 day−1 in the Laptev, East Siberian, and Chukchi seas, respectively, corresponding to annual sea-wide fluxes of 0.83, 0.62, and 0.03 Tg year−1. These EC results answer concerns that previous diffusive emission estimates, which excluded bubbling, may underestimate total emissions. We assert that bubbling dominates sea-air CH4 fluxes in only small constrained areas: A ~100-m2 area of the East Siberian Sea showed sea-air CH4 fluxes exceeding 600 mg m−2 day−1; in a similarly sized area of the Laptev Sea, peak CH4 fluxes were ~170 mg m−2 day−1. Calculating additional emissions below the noise level of our EC system suggests total ESAS CH4 emissions of 3.02 Tg year−1, closely matching an earlier diffusive emission estimate of 2.9 Tg year−1.

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Variability in Sea Ice Melt Onset in the Arctic Northeast Passage: Seesaw of the Laptev Sea vs. the East Siberian Sea

10.5194/egusphere-egu21-14379 ◽

2021 ◽

Author(s):

Hongjie Liang ◽

Jie Su

Keyword(s):

Heat Flux ◽

Sea Ice ◽

Sensible Heat Flux ◽

Storm Tracks ◽

The Arctic ◽

Laptev Sea ◽

Easterly Wind ◽

East Siberian Sea ◽

Atmospheric Circulation Indices ◽

The Laptev Sea

The ice/snow melt onset (MO) is a critical triggering signal for ice-albedo positive feedback in the Arctic. Concerning the Northeast Passage (NEP), for 1979-1998, the MO in the East Siberian Sea (ESS) occurred generally earlier than that in the Laptev Sea (LS). However, for 1999-2018, the LS experienced significantly earlier MO than did the ESS in several years. This phenomenon is identified as the MO Seesaw (MOS), i.e., the MO difference between the LS and ESS. For the positive MOS, storm tracks in May tend to cover the ESS rather than the LS and easterly wind prevails and shifts slightly to a northerly wind in the ESS, resulting in higher surface air temperature (SAT) and total-column water vapor (TWV) and earlier MO in the ESS. For the negative MOS, storm tracks are much stronger in the LS than in the ESS and prominent southerly/southwesterly wind brings warm air from coastal land towards the LS. The effect of the Barents Oscillation (BO) on the MOS could be dated back to April. When the Barents Sea is centered with a low SLP in April, sea ice in the LS would be driven away from the coasts, leading to a lower sea ice area (SIA), which increases the surface latent heat flux and humidifies the overlying atmosphere. Along with an enhanced downward sensible heat flux, earlier regional average MO occurs in the LS. For 1999-2018, the MOS was more closely related to both the local variables and the large-scale atmospheric circulation indices.

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