Anthropogenic impact on the runoff of Russian rivers emptying into the Arctic Ocean

The effect of water consumption and reservoirs on the regime and water resources of Russian rivers emptying into the Arctic Ocean is discussed. The impact of reservoirs on the annual and seasonal runoff of regulated rivers is estimated. The transformation of this impact along the rivers down to their outlet sections is analyzed. Possible variants of the development of water management measures in Arctic river basins in the first quarter of the 21st century are considered.     

Anthropogenic transformations of the Arctic ecosystem of Lake Imandra: Tendencies for recovery after long period of pollution

Transformation of an Arctic aquatic ecosystem (a case study of Lake Imandra) under the impact of a mining industrial complex is considered. Water chemical composition and the ecosystem’s structural components (phyto- and zooplankton, zoobenthos, and ichthiofauna) are analyzed for the following periods: the preindustrial background (reference) conditions, industrial development of mineral resources and strong anthropogenic impact, industrial recession and decreased anthropogenic impact, and stabilization. The main regularities of the aquatic ecosystem successions under the conditions of anthropogenic loads and their decrease are established.     

Organochlorine pesticide and trace metal monitoring of Russian rivers flowing to the Arctic Ocean: 1990-1996

Information is presented on the concentrations of organochlorine pesticides (HCHs and DDT residues) and trace metals (Fe, Cu, Zn and Ni) in waters of 15 large Russian rivers flowing to the Arctic Ocean during 1990-1996. Estimates of the corresponding annual fluxes are made. Other contaminants (Hg, Pb, Cr, Mn, beta-HCH and dihydroheptachlor) were examined briefly. Concentration data are presented as averaged annual means for each of the seven years with the ranges, standard deviations and numbers of samples. Also given are data on locations, the methods of analysis and limited quality assurance data. Data on discharges to the Northern Seas for the more frequently monitored contaminants are given for rivers accounting for >70% of the total northerly flows. Scaled-up fluxes to account for unmonitored rivers as well are given for each sea; totals over the period were: Fe, 1452; Cu, 15; Zn, 59 (x 10(3) t yr(-1)); alpha-HCH, 25; gamma-HCH, 44 (t yr(-1)). Ni was monitored at too few rivers to estimate its total Russian flux. The fluxes for the HCHs considerably exceed previous estimates and indicate that the Arctic Ocean is not in balance as much as was previously believed.     

Long-term trends in total and anthropogenic discharge of organic and biogenic substances by Russian rivers into the Arctic and Pacific seas

The discharge of organic and biogenic substances by Russian rivers into the Arctic and Pacific seas, their anthropogenic component, and the trends in variations in the runoff of some components in individual periods of 1981–2000 are estimated.     

Reservoirs in the Drainage Basins of Russian Arctic Seas

Water Resources - The space and time distribution of reservoirs over the drainage basins of Arctic seas within Russian Federation territory and the main rivers flowing into the Arctic Ocean is...     

Anthropogenic Processes in Continental Waters of Arctic Regions and Criteria for Their Assessment

Development features of anthropogenic processes in continental waters in the Arctic Basin, including eutrophication, acidification, and toxic pollution, are characterized. The major changes in the ecosystems and the formation periods of hazardous situations are demonstrated. Criteria are suggested for the diagnostics of unfavorable processes and the need of more stringent water quality standards is substantiated.     

Anthropogenic iodine-129 in the Arctic Ocean and Nordic Seas: numerical modeling and prognoses

A numerical model simulation has been used to predict extent and variability in the anthropogenic (129)I pollution in the Arctic Ocean and Nordic Seas region over a period of 100 years. The source function of (129)I used in the model is represented by a well-known history of discharges from the Sellafield and La Hague nuclear reprocessing facilities. The simulations suggest a fast transport and large inventory of the anthropogenic (129)I in the Arctic and North Atlantic Oceans. In a fictitious case of abrupt stop of the discharges, a rapid decline of inventories is observed in all compartments except the North Atlantic Ocean, the deep Nordic Seas and the deep Arctic Ocean. Within 15 years after the stop of releases, the model prediction indicates that near-equilibrium conditions are reached in all compartments.     

The issue of global warming and changes in the runoff of Russian rivers

Maps of a series of characteristics were calculated and constructed for RF territory, including mean values of changes in runoff depths (evaluated by the main climate models of the Intergovernmental Panel on Climate Change) due to greenhouse effect estimated for 2040–2070; root-mean-square deviations from these values; relative errors of the estimates; mean values of changes in the runoff depth for different scenarios of greenhouse gas emissions; absolute and relative deviations of these values from their means for scenarios and integration of models. Chronological forecasts of possible changes in the mean runoff values for the rivers of Volga, Northern Dvina, Pechora, Ob, Yenisei, Lena, Yana, Indigirka, Kolyma, and Amur up to 2100 are calculated, and the root-mean-square errors of these characteristics are evaluated for the maximum number of uncertainties in the forecast. The greenhouse effect is shown to be less significant, other factors being the same, for rivers with small drainage basins and rivers with small modulus of flow.     

Pu, Cs and excess Pb in Russian Arctic sediments

The activity ratios of Pu and radiocesium isotopes have been used to delineate the major sources (such as global and close-in (debris) fallout, nuclear fuel reprocessing and fabrication plant effluents) in the environment. We have measured ²³⁸Pu, ^239,240Pu, ¹³⁷Cs, and excess ²¹⁰Pb concentrations in 107 surficial sediments as well as in 5 sediment cores collected in the summer months of 1993 and 1994 from the Ob and Yenisey Rivers (Russia) and the Kara sea. A comparison of the sediment core inventories of ^239,240Pu and ¹³⁷Cs, along with the ²³⁸Pu/^239,240Pu activity ratios, with those expected from global fallout allows us to estimate the relative amounts, if any, of reactor-derived ²³⁸Pu and ^239,240Pu from the dumped reactor sites in the study area.

In surficial sediment samples collected in 1993 and 1994, the ^239,240Pu concentrations varied between 4.2 and 856 mBq kg⁻¹, with a mean of 239 mBq kg⁻¹. In samples with a measurable ²³⁸Pu, the ²³⁸Pu/^239,240Pu activity ratios varied between 0.010 and 0.069, with an average value of 0.035 ± 0.014. This range can be compared to the average ²³⁸Pu/^239,240Pu activity ratio of 0.030 for the year 1993 from nuclear weapons testing and SNAP fallout obtained from soil studies, indicating very little (≤ 5%) additional sources of ²³⁸Pu to the sediments in the study area. The inventories of Pu in the 5 sediment cores from the study area varied between 2.67 ± 0.67 and 24.5 ± 2.2 Bq m⁻² with a mean value of 8.83 Bq m⁻². The ¹³⁷Cs concentrations in the upper 3 cm of the sediments varied between below detection limit to 71.4 Bq kg⁻¹, with a mean of 14.9 Bq kg⁻¹. The ¹³⁷Cs inventories in the 5 sediment cores varied between 156.7 ± 28.3 and 1600 ± 153.3 Bq m⁻², with a mean value of 583.3 Bq m⁻². The mean ratio of inventories of Pu to that of ¹³⁷Cs, 0.015, is comparable to the values in other places in the Arctic region. There is a significant correlation between total organic carbon and concentrations of ¹³⁷Cs, ^239,240Pu and ²¹⁰Pb, suggesting that organic matter-enriched fine particles are a likely carrier phase for these nuclides. The ratio of ¹³⁷Cs/^239,240Pu also suggests that most of these nuclides are derived from global fallout.     

Remotely sensed rivers in the Anthropocene: state of the art and prospects

The rivers of the world are undergoing accelerated change in the Anthropocene, and need to be managed at much broader spatial and temporal scales than before. Fluvial remote sensing now offers a technical and methodological framework that can be deployed to monitor the processes at work and to assess the trajectories of rivers in the Anthropocene. In this paper, we review research investigating past, present and future fluvial corridor conditions and processes using remote sensing and we consider emerging challenges facing fluvial and riparian research. We introduce a suite of remote sensing methods designed to diagnose river changes at reach to regional scales. We then focus on identification of channel patterns and acting processes from satellite, airborne or ground acquisitions. These techniques range from grain scales to landform scales, and from real time scales to inter-annual scales. We discuss how remote sensing data can now be coupled to catchment scale models that simulate sediment transfer within connected river networks. We also consider future opportunities in terms of datasets and other resources which are likely to impact river management and monitoring at the global scale. We conclude with a summary of challenges and prospects for remotely sensed rivers in the Anthropocene. © 2019 John Wiley & Sons, Ltd.     

Arctic gravity exploration: state of the art and prospects

The application of the airborne gravimetry method for gravity measurements in the Arctic is considered. This method has been extensively employed in foreign studies for determining the figure of the Earth in high-latitude conditions. The possibility of conducting comparative studies along the extensive survey lines and the necessity of aerogravimetry studies for improving the global Earth’s gravity field (EGF) models are discussed. The possibility of the efficient application of the modern EGF models for estimating the systematical errors for different types of gravimetry surveys and exploring the influence of the anomalous far-zone field in the calculations of the plumb line deviations is demonstrated.     

Macrophytes as indicators of the ecological state of small rivers in Minsk Region

The ecological state of 18 small rivers in Minsk Region was for the first time estimated by jointly used macrophyte-based characteristics, including saprobity index, biological macrophyte index for rivers, and a scale of cenotic/supercenotic organization of aquatic and coastal-aquatic plants. Rivers with relatively safe ecological status were shown to dominate, while other rivers are in a safe and satisfactory state. The proposed approach to determining the ecological quality of watercourses is based on the calculation of a complex characteristic, i.e., an integral macrophyte index of small river ecological status; this index has been developed in the context of a classification scheme of surface water quality in the National Environmental Monitoring System of the Republic of Belarus.     

On the Need for Accurate Monitoring of the Geomagnetic Field during Directional Drilling in the Russian Arctic

Izvestiya, Physics of the Solid Earth - Abstract—The readings of well magnetometers used in directional drilling may be distorted by geomagnetic storms and substorms. These distortions occur...     

Concentrations of Cd, Pb, Zn and Cu in pristine wetlands of the Russian Arctic

Background concentrations of Cd, Pb, Zn and Cu were studied for wetlands from pristine regions of the Russian Arctic: Severnaya Zemlya Archipelago, Vrangel Island, Arctic deserts and tundra of the North Taimyr Peninsula, Byrranga Mountainous Area, tundra zone of Mid-Siberia, North-East Siberia, Far North-East, and Amguemo-Anadyr Mountainous Area. These wetland regions were known to be relatively remote and isolated, with little human population and no local industry. Samples were collected during the period 1976–1993 and included: (a) snow and thaw water, (b) particulate matter, (c) bottom sediments, (d) hydric organo-mineral deposits and hydric soils, (e) polygonal bog peat and sedge-moss peat. Observed ranges for the background concentrations of Cd, Pb, Zn, and Cu in water were 0.001–0.15, 0.02–0.36, 0.05–2.9 and 0.23–6.2 μg l⁻¹ respectively. For (b)–(e) the corresponding values were [0.04–0.46; 1.3–41; 8.6–190; 0.7–63]; [0.05 0.99; 1.5–49; 2.5–153; 2.4–55]; [0.05–0.96; 1.7–44; 2.2–154; 2.0–82] and [0.03–0.83; 1.3–31; 2.1–124; 1.7–68] mg kg⁻¹, dry wt, respectively. Although full assessment of the pristine nature of the wetlands was not possible due to the limited data available, the observed metal concentrations reflect natural geochemical background levels and influence from localized minor ore-deposits present for some regions. In general, there was no evidence of impact from remote industrial regions of the Russian Arctic.     

Concentrations of Cd, Pb, Zn and Cu in contaminated wetlands of the Russian Arctic

The spatial distribution of the concentrations of heavy metals Cd, Pb, Zn and Cu were studied for contaminated wetlands located by industrial centres and villages influenced by anthropogenic contamination in the Russian Arctic. For comparison, non-contaminated wetlands were also studied in neighbouring areas. Samples were collected during the period 1977–1994 and included: (a) water, (b) particulate matter, (c) bottom sediments, (d) hydric soils and (e) hummock bog peat and polygonal bog peat. For impacted wetlands, the observed ranges for the concentrations of Cd, Pb, Zn, and Cu in water were 0.12–0.8, 0.9–2.5, 2.4–15 and 16–34 μg l⁻¹, respectively. For (b)- (e) the corresponding values were [1.2–5.4; 24–37; 120–320; 80–116]; [6.4–17; 34–59; 240–570; 115–280]; [10–32; 57–78; 315–480; 87–350] and [5.1–53; 51–150; 125–520; 80–440] mg/kg, dry wt, respectively. The metal concentrations were up to 1000 times higher than background levels determined for non-contaminated wetlands in the Russian Arctic. The contaminants appear to be a direct result of localized anthropogenic activity, arising primarily from geoprospecting, the oil and coal industry, and domestic waste.     

Current state and prospects of the development of an Arctic seismic monitoring system

The expansion of industrial and defense activities in the Arctic as part of the execution of a state program on the development of its territory requires seismic safety assurance of constructed and existing critical facilities. The data presented in this paper show that the current understanding of the seismicity of the Arctic and particularly of its shelf given in building regulations is quite simplistic and does not reflect the complexity of the situation and the intensity of expected seismic effects. To a large extent, safety problems can be solved by the seismic monitoring of the area. For this purpose, it is necessary to expand existing networks of seismic stations, to equip them with tools for monitoring groups, and to increase the number of island seismic stations. The primary task is to refine the seismic zoning of Arctic territories based on the new data.     

The hyperturbid state of the water column in estuaries and rivers: the importance of hindered settling

Over the last few decades, some estuaries have undergone a transition to a hyperturbid state, characterised by suspended sediment concentrations of several grammes per litre averaged over the water column. To improve our understanding of this transition and of naturally hyperturbid estuaries, we systematically identify the processes allowing for high suspended sediment concentrations using a water column (1DV) model. Under a range of realistic forcing conditions, the state of the water column can be characterised by one of two equilibrium states. The first is an erosion-limited state, in which there still is sediment available for erosion at the bed. We find that this state only occurs with relatively low concentrations. The second is a supply-limited state, in which all erodable sediment is in suspension. The concentration in this state depends entirely on the amount of sediment in the system and can potentially be very high. We identify the conditions under which the state of the water column can jump from a low to a high concentration and identify hysteresis in the transition between the two states. The mechanism responsible for this hysteresis is hindered settling. It thus follows that hyperturbidity is only possible in a supply-limited state. From this observation we derive a necessary condition for an estuarine system to make the transition from low turbidity to hyperturbidity in a 1DV context. This is an important step towards understanding why some estuaries are hyperturbid and assessing the risk that particular estuaries may become hyperturbid in the future.     

Anthropogenic Radionuclides in the Caspian Sea

Analysis and interpretation of the distribution of anthropogenic radionuclides ⁹⁰Sr, ¹³⁷Cs, and ^239,240Pu in the Caspian Sea water are presented. These radionuclides are shown to be of environmental importance and to be useful for studying water mass dynamics.     

Benthic communities as influenced by nuclear testing and radioactive waste disposal off Novaya Zemlya in the Russian Arctic

On the material of sampling, accomplished in: (i) Chernaya Inlet of the Barents Sea (one of the flats of Novaya Zemlya Nuclear Test Site), (ii) in the Open Kara Sea and (iii) on the shoal off Novaya Zemlya from Stepovogo Fjord to Abrosimov Fjord (sites of radioactive waste disposal with activity 90% from total for the Kara Sea), characteristics of macro-, meio- and microbenthic bottom communities on the areas of potential radioactive danger are presented. Significant changes in macro- and meiobenthic communities are not revealed. In Chernaya Inlet, where three nuclear explosions were held in 1955–1961, disturbances in microbenthic protozoa communities are found. These disturbances expressed in the infusoria elimination from the fauna of the inlet deep-water sites and in morphological abnormality of this group individuals in population, inhabiting low depth of the inlet top. The assumed origin of revealed disturbances is high concentration (by 3–4 orders of magnitude above the background) of plutonium in bottom sediments of the inlet. Similar responses of the microbenthic flagellates are not detected.