Methane in Water and Bottom Sediments in Three Sections in the Kara and Laptev Seas

The methane content in water and bottom sediments was measured in vertical sections: Lena River Delta–continental slope (the Laptev Sea), Taimyr Peninsula–Voronin Trough, and along the Novaya Zemlya Archipelago. The methane concentrations varied from 2.5 to 70 nmol/L and from 590 to 2600 nmol/L in the water column and sediments, respectively. Most of the surface water samples showed oversaturation in methane (up to 19-fold, fourfold on average), which determined the water–atmosphere direction of methane fluxes, which amounted to 1–400 mol/km² day (52 mol/km² day on average).     

Primary production and fluxes of organic carbon to the seabed in the Eurasian arctic seas, 2003–2012

The primary production and fluxes of organic matter to the seabed and their variations were estimated in the Greenland, Barents, Kara, Laptev, East Siberian, and Chukchi seas in 2003–2012 on the basis of satellite and in situ data. When counting the open water area with the assumptions made for the assessment of the primary production in the sea areas hidden under clouds, an increase in primary production was recorded in all these seas, the total production (phytoplankton and ice algae) has grown from 250 × 10⁶ to 400 × 10⁶ t of C per year over the last ten years. The calculation of the OM flux to the seabed showed growth for certain seas from 4 to 12% per year.     

Characteristic of quaternary sedimentation on a shelf of the Laptev Sea according to the molecular composition of n-alkanes

The molecular composition and distribution of the concentration of n-alkanes are considered for sediments of boreholes drilled in the shallow part of the Laptev Sea, in the area of Buor Khaya Gulf. The diverse molecular composition of n-alkanes is dominated by long-chain odd homologs, which indicate terrigenous organic matter (OM). Heterogeneous distribution and burial of OM are shown under conditions of pulsating contribution of river and thermoabrasive material and multiple changes in them up to hiatuses in sedimentation.     

Primary production and fluxes of organic carbon to the seabed in the Russian Arctic seas as a response to the recent warming

The primary production and fluxes of organic matter to the seabed and their variations were estimated in the Norwegian, Greenland, Barents, Kara, Laptev, East Siberian, and Chukchi seas in 2003–2008 on the basis of satellite and field data. When counting the open water area with the assumptions made for the assessment of the primary production in the regions hidden under clouds, the reliable trends of its variability (increasing) were revealed only in the Greenland, Barents, and Kara seas.     

Masses of carbon in the Earth’s hydrosphere

Recent data were summarized on the concentration and mass of inorganic and organic carbon in reservoirs of the Earth’s hydrosphere. We compared carbon masses and accumulation conditions in the surface hydrosphere and waters of the sedimentary shell and proportions between carbonate, dissolved, and suspended particulate organic carbon. It was shown that the total masses of carbon in the surface hydrosphere and in the waters of the sedimentary shell are approximately equal to 80 × 10¹⁸ g C at an organic to carbonate carbon ratio of 1 : 36 and 1 : 43, respectively. Three main forms of organic compounds in the ocean (living organisms, suspended particles, and dissolved species) occur in the proportion 1 : 13 : 250 and form the pyramid of masses 4 × 10¹⁵ g, 50 × 10¹⁵ g, and 1000 × 10¹⁵ g C_org. The descending sequence of the organic to carbonate carbon ratio in water, ocean (1 : 36) > glaciers (1 : 8) > lakes (1 : 2) > rivers (1 : 0.6) > wetlands (1 : 0.3), is in general consistent with an increase in the same direction in the mean concentrations of organic matter: 0.77 mg C_org/L in the ocean, 0.7 mg C_org/L in glaciers, 6–30 mg C_org/L in lakes, 15 mg C_org/L in rivers, and 75 mg C_org/L in wetlands. Both the mean concentrations and masses of dissolved organic matter in the pore waters of oceanic sediments and in the waters of the sedimentary shell are similar: 36–37 mg/L and 5 × 10¹⁸ and 5.6 × 10¹⁸ g, respectively. The mass of carbonate carbon in the pore waters of the ocean, (19–33) × 10¹⁸ g, is comparable with its mass in the water column, 38.1 × 10¹⁸ g.     

Ionic composition of pore water in shallow shelf deposits of the Laptev Sea

The cationic and anionic compositions of pore water in shallow deposits of Buor-Khaya Bay is studied. Significant concentration heterogeneity of the vertical ionic profile in the studied drill columns is shown. It is established that the vertical ionic profile of shelf deposits of the Laptev Sea is basically formed under the influence of thawing of underwater permafrost, hydrodynamic conditions, the water mass, and heat flows and depends on the lithological and granulometric types of the deposits. The highest concentrations of ions are registered in plant detritus represented by ground grass vegetation. A relationship between the ionic composition of pore water and cryogenic state of the sequence and its variability is demonstrated using the method of major components.     

Subsea Permafrost Thawing as a Factor of Changes in the Elemental Composition

Doklady Earth Sciences - The differences in the concentration of elements between thawed and frozen sediments were shown in the samples from two boreholes from the coastal zone of the Laptev Sea...     

COLOR SYNTHESIS OF MULTISPECTRAL IMAGERY FOR MAPPING PURPOSES

The authors describe common Soviet practice in the making of false-color composite imagery for visual interpretation. Also addressed are standard image interpretation techniques: figure-ground color contrast, color separation (number of color gradations occurring within an average contrast range), and so-called landscape indicator techniques. Related issues, such as selection of spectral bands and filters for specific interpretation tasks, and the changing reflectance characteristics of band-specific intermediate images, receive attention as well. Tables and figures illustrating relationships between photographic contrast, film contrast ratings, optical densities, and spectral bands are included. Translated from: Geodeziya i kartografiya, 1985, No. 4, pp. 41-46.     

Transport of the colloid matter of riverine runoff through estuaries

A procedure for separating the colloid component of natural waters is proposed. It was shown that this component is the main form of matter transfer in Ob River runoff, because the mass of colloid substance is two orders of magnitude higher than that of particulate matter in the outer part of the estuary. Simulation and field experiments revealed the influence of nature and concentration of organic matter on their ability to stabilize or flocculate clay particles with an increase in salinity, thus affecting the range of transfer of riverine runoff matter. It was shown that the interaction of humic acids and clay particles, as well as the increase in hydrophobic properties of a flocculant, improve flocculation efficiency. Criteria are proposed to recognize in the estuarine region areas of pronounced contribution of flocculation processes to sedimentation of fine particles. It is shown that the newly formed organic matter produced by biota under saline stress might be flocculants of fine particulate matter.