Stable oxygen and carbon isotopes in modern benthic foraminifera from the Laptev Sea shelf: implications for reconstructing proglacial and profluvial environments in the Arctic

Article is devoted to a research of warm-loving species of planktonic foraminifera in the Arctic. Fauna of the planktonic and the benthic foraminifera in the surface and subsurface layer of the Kara Sea sediments was studied. It is found that complexes of the benthic foraminifera are characteristic for this region. It is shown also what at complexes of planktonic foraminifera the significant amount of kinds of warm-loving species from equatorial, tropical and subtropical regions are presented. It is supposed that they are brought to the Arctic by a current from low latitudes. The received results are compared with the published data. Earlier it was shown that alive warm-loving species meet in waters of the Laptev Sea and their shells were observed in the present sediments of the marginal part of the Laptev Sea.

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Stable oxygen and carbon isotopes of carbonate concretions of the Miocene Yeonil Group in the Pohang Basin, Korea: Types of concretions and formation condition

Sedimentary Geology ◽

10.1016/j.sedgeo.2005.09.005 ◽

2006 ◽

Vol 183 (1-2) ◽

pp. 15-30 ◽

Cited By ~ 25

Author(s):

Kyung Sik Woo ◽

Boo-Keun Khim

Keyword(s):

Carbon Isotopes ◽

Formation Condition ◽

Oxygen And Carbon Isotopes ◽

Carbonate Concretions ◽

Pohang Basin ◽

Stable Oxygen

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Ocean-Bottom Seismographs Based on Broadband MET Sensors: Architecture and Deployment Case Study in the Arctic

Sensors ◽

10.3390/s21123979 ◽

2021 ◽

Vol 21 (12) ◽

pp. 3979

Author(s):

Artem A. Krylov ◽

Ivan V. Egorov ◽

Sergey A. Kovachev ◽

Dmitry A. Ilinskiy ◽

Oleg Yu. Ganzha ◽

...

Keyword(s):

Site Response ◽

The Arctic ◽

Laptev Sea ◽

Ocean Bottom ◽

Arctic Seas ◽

Shirshov Institute ◽

Study Results ◽

Ocean Bottom Seismographs ◽

The Laptev Sea

The Arctic seas are now of particular interest due to their prospects in terms of hydrocarbon extraction, development of marine transport routes, etc. Thus, various geohazards, including those related to seismicity, require detailed studies, especially by instrumental methods. This paper is devoted to the ocean-bottom seismographs (OBS) based on broadband molecular–electronic transfer (MET) sensors and a deployment case study in the Laptev Sea. The purpose of the study is to introduce the architecture of several modifications of OBS and to demonstrate their applicability in solving different tasks in the framework of seismic hazard assessment for the Arctic seas. To do this, we used the first results of several pilot deployments of the OBS developed by Shirshov Institute of Oceanology of the Russian Academy of Sciences (IO RAS) and IP Ilyinskiy A.D. in the Laptev Sea that took place in 2018–2020. We highlighted various seismological applications of OBS based on broadband MET sensors CME-4311 (60 s) and CME-4111 (120 s), including the analysis of ambient seismic noise, registering the signals of large remote earthquakes and weak local microearthquakes, and the instrumental approach of the site response assessment. The main characteristics of the broadband MET sensors and OBS architectures turned out to be suitable for obtaining high-quality OBS records under the Arctic conditions to solve seismological problems. In addition, the obtained case study results showed the prospects in a broader context, such as the possible influence of the seismotectonic factor on the bottom-up thawing of subsea permafrost and massive methane release, probably from decaying hydrates and deep geological sources. The described OBS will be actively used in further Arctic expeditions.

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On the biogeochemical signature of the Lena River from its headwaters to the Arctic Ocean

Biogeosciences Discussions ◽

10.5194/bgd-8-2093-2011 ◽

2011 ◽

Vol 8 (2) ◽

pp. 2093-2143 ◽

Cited By ~ 6

Author(s):

I. P. Semiletov ◽

I. I. Pipko ◽

N. E. Shakhova ◽

O. V. Dudarev ◽

S. P. Pugach ◽

...

Keyword(s):

Organic Carbon ◽

Arctic Ocean ◽

River Discharge ◽

Total Carbon ◽

The Arctic ◽

Time Shift ◽

Laptev Sea ◽

Lena River ◽

The Arctic Ocean ◽

The Laptev Sea

Abstract. The Lena River integrates biogeochemical signals from its vast drainage basin and its signal reaches far out over the Arctic Ocean. Transformation of riverine organic carbon into mineral carbon, and mineral carbon into the organic form in the Lena River watershed, can be considered a quasi-equilibrated processes. Increasing the Lena discharge causes opposite effects on total organic (TOC) and inorganic (TCO2) carbon: TOC concentration increases, while TCO2 concentration decreases. Significant inter-annual variability in mean values of TCO2, TOC, and their sum (TC) has been found. This variability is determined by changes in land hydrology which cause differences in the Lena River discharge, because a negative correlation may be found between TC in September and mean discharge in August (a time shift of about one month is required for water to travel from Yakutsk to the Laptev Sea). Total carbon entering the sea with the Lena discharge is estimated to be almost 10 Tg C y−1. The annual Lena River discharge of particulate organic carbon (POC) may be equal to 0.38 Tg (moderate to high estimate). If we instead accept Lisytsin's (1994) statement concerning the precipitation of 85–95% of total particulate matter (PM) (and POC) on the marginal "filter", then only about 0.03–0.04 Tg of POC reaches the Laptev Sea from the Lena River. The Lena's POC export would then be two orders of magnitude less than the annual input of eroded terrestrial carbon onto the shelf of the Laptev and East Siberian seas, which is about 4 Tg. The Lena River is characterized by relatively high concentrations of primary greenhouse gases: CO2 and dissolved CH4. During all seasons the river is supersaturated in CO2 compared to the atmosphere: up to 1.5–2 fold in summer, and 4–5 fold in winter. This results in a narrow zone of significant CO2 supersaturation in the adjacent coastal sea. Spots of dissolved CH4 in the Lena delta channels may reach 100 nM, but the CH4 concentration decreases to 5–20 nM towards the sea, which suggests only a minor role of riverborne export of CH4 for the East Siberian Arctic Shelf (ESAS) CH4 budget in coastal waters. Instead, the seabed appears to be the source that provides most of the CH4 to the Arctic Ocean.

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Satellite-based sea ice thickness changes in the Laptev Sea from 2002 to 2017: comparison to mooring observations

The Cryosphere ◽

10.5194/tc-14-2189-2020 ◽

2020 ◽

Vol 14 (7) ◽

pp. 2189-2203

Author(s):

H. Jakob Belter ◽

Thomas Krumpen ◽

Stefan Hendricks ◽

Jens Hoelemann ◽

Markus A. Janout ◽

...

Keyword(s):

Sea Ice ◽

Source Region ◽

European Space Agency ◽

The Arctic ◽

Ice Thickness ◽

Laptev Sea ◽

Validation Data ◽

Data Set ◽

Sea Ice Thickness ◽

The Laptev Sea

Abstract. The gridded sea ice thickness (SIT) climate data record (CDR) produced by the European Space Agency (ESA) Sea Ice Climate Change Initiative Phase 2 (CCI-2) is the longest available, Arctic-wide SIT record covering the period from 2002 to 2017. SIT data are based on radar altimetry measurements of sea ice freeboard from the Environmental Satellite (ENVISAT) and CryoSat-2 (CS2). The CCI-2 SIT has previously been validated with in situ observations from drilling, airborne remote sensing, electromagnetic (EM) measurements and upward-looking sonars (ULSs) from multiple ice-covered regions of the Arctic. Here we present the Laptev Sea CCI-2 SIT record from 2002 to 2017 and use newly acquired ULS and upward-looking acoustic Doppler current profiler (ADCP) sea ice draft (VAL) data for validation of the gridded CCI-2 and additional satellite SIT products. The ULS and ADCP time series provide the first long-term satellite SIT validation data set from this important source region of sea ice in the Transpolar Drift. The comparison of VAL sea ice draft data with gridded monthly mean and orbit trajectory CCI-2 data, as well as merged CryoSat-2–SMOS (CS2SMOS) sea ice draft, shows that the agreement between the satellite and VAL draft data strongly depends on the thickness of the sampled ice. Rather than providing mean sea ice draft, the considered satellite products provide modal sea ice draft in the Laptev Sea. Ice drafts thinner than 0.7 m are overestimated, while drafts thicker than approximately 1.3 m are increasingly underestimated by all satellite products investigated for this study. The tendency of the satellite SIT products to better agree with modal sea ice draft and underestimate thicker ice needs to be considered for all past and future investigations into SIT changes in this important region. The performance of the CCI-2 SIT CDR is considered stable over time; however, observed trends in gridded CCI-2 SIT are strongly influenced by the uncertainties of ENVISAT and CS2 and the comparably short investigation period.

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