Subsurface Hydrosphere Research Articles

The role of atmospheric conditions in CO2 and radon emissions from an abandoned water well

Boreholes and wells are complex boundary features at the earth-atmosphere interface, connecting the subsurface hydrosphere, lithosphere, and biosphere to the atmosphere above it. It is important to understand and quantify the air exchange rate of these features and, consequently their contribution as sources for greenhouse gas (GHG) emissions to the atmosphere. Here, we investigate the effect of atmospheric conditions, namely atmospheric pressure and temperature, on air, CO2, and radon transport across the borehole-ambient atmosphere interface and inside a 110-m deep by 1-m diameter borehole in northern Israel. Sensors to measure temperature, relative humidity, CO2, and radon were placed throughout a cased borehole. A standard meteorological station was located above the borehole. Data were logged at a high 0.5-min resolution for 9 months. Results show that climatic driving forces initiated 2 different advective air transport mechanisms. (1) Diurnal and semidiurnal atmospheric pressure cycles controlled daily air transport events (barometric pumping); and (2) There was a correlation between borehole-atmosphere temperature differences and transport on a seasonal scale (thermal-induced convection). Barometric pumping was identified as yielding higher fluxes of vadose zone gases than thermal-induced convection. Air velocities inside the borehole and CO2 emissions to the atmosphere were quantified, fluctuating from zero up to ~6 m/min and ~5 g-CO2/min, respectively. This research revealed the mechanisms involved in the process throughout the year and the potential contribution role played by boreholes to GHG emissions.

Distribution of environmental tritium in rivers, groundwater, mine water and precipitation in Goa, India

Tritium concentration in rivers, groundwater, precipitation and mine pits water, all over Goa state was characterized to find out spatial and temporal variability of tritium. Twenty four water samples were collected during pre-monsoon and post-monsoon and analyzed for their tritium concentration. The mean tritium concentration in surface and sub-surface hydrosphere is 2.5 (±0.6) TU. The mean concentration of tritium in rivers, groundwater, mines pits water and rain water are 2.9 (±0.5) TU, 1.95 (±0.5) TU, 2.5(±0.3) TU and 3.1(±0.1) TU respectively. The tritium distribution in all the samples shows modern precipitation (post-1950) component in surface and sub-surface hydrosphere of Goa. The HYSPLIT4.0 air mass trajectory model and atmospheric circulation pattern suggest that the moisture origin was from the Arabian Sea and this low tritium moisture is diluting the tritium concentration of surface hydrosphere near the coastal area. The tritium concentration in surface hydrosphere shows more and more enrichment as one move inland (i.e. away from the coast). Significant seasonal change is observed in the surface hydrosphere. The pre-monsoon samples showed higher tritium concentration than post-monsoon samples. This may be due to high rate of re-evaporation of water and a reduction in the supply of oceanic moisture during the summer (pre-monsoon).

New insights into the dynamics of adsorption equilibria of humic matter as revealed by radiotracer studies

The mobility of contaminants in the subsurface hydrosphere can be governed by their interaction with aquatic humic substances, which may act as carriers. For modelling migration processes, retardation of humic molecules at mineral surfaces must be considered. There is, however, a lack of clarity concerning the reversibility of adsorption of these natural polyelectrolytes. In this work, evidence was provided that a dynamic adsorption equilibrium exists. For this purpose, adsorption of humic substances (purified Aldrich humic acid and an aquatic fulvic acid) onto kaolinite was examined in tracer exchange studies by means of 14C-labelled humic material. In addition, the kinetics of adsorption and desorption were investigated in batch experiments.Attaining the equilibrium state of adsorption took considerably longer for the humic acid than for the fulvic acid (24h and 4h, respectively). In desorption experiments, initiated by diluting the supernatant at constant pH, no net release was observed for both substances within a time frame of 4weeks. However, when introducing radiolabelled humic or fulvic acid as a tracer into pre-equilibrated adsorption systems in the state of surface saturation, quantitative exchange was found to take place. This indicates that adsorption of humic matter is in fact a reversible process, albeit an exchange time of more than 4weeks was required for both humic materials. Models for humic-bound contaminant transport (presuming dynamic equilibria) are thus applicable under appropriate conditions.

Global hydrogeological systems and groundwater of the Pacific segment of the Earth

The paper presents the main results of almost half-century-long theoretical and applied studies by the late K.P. Karavanov dedicated to hydrogeological systems of continents and the oceanic floor as well as to the regional hydrogeology of the Pacific segment of the Earth. This research is not yet over; it is being developed by his followers and serves as a basis for the further study of the subsurface hydrosphere on land and the sea and ocean floor.

Reflection of neotectonic processes in the subsurface hydrosphere of the Verkhnii Amur region

New data on the neotectonic processes, seismicity, and earth’s interior degassing in the southern part of the Zeya-Bureya artesian basin and their influence on the hydrogeological processes are considered. The helium-measuring and atmochemical methods that were used for defining zones of elevated permeability and channels of the fluid discharge revealed the discrete permeability of fractures and confinement of active “breathing” zones to intersections of faults that border high-order artesian basins and internal hydrogeological massifs. The confinement of discharge sites of different-type mineralized waters to definite structural-tectonic junctions of seismogenic zones is considered. Their description and trace-element composition are reported. The results of long-term helium measurements for understanding the dynamics of the earth’s interior degassing and the fluid regime in the Konstantinovka deposit of mineral chloride sodic waters are presented.

Valley network-fed, open-basin lakes on Mars: Distribution and implications for Noachian surface and subsurface hydrology

A new catalog of 210 open-basin lakes (lakes with outlet valleys) fed by valley networks shows that they are widely distributed in the Noachian uplands of Mars. In order for an outlet valley to form, water must have ponded in the basin to at least the level of the outlet. We use this relationship and the present topography to directly estimate the minimum amount of water necessary to flood these basins in the past. The volumes derived for the largest lakes ( ∼ 3 × 10 4 to ∼ 2 × 10 5 km 3 ) are comparable to the largest lakes and small seas on modern Earth, such as the Caspian Sea, Black Sea, and Lake Baikal. We determine a variety of other morphometric properties of these lakes and their catchments (lake area, mean depth, volume, shoreline development, outlet elevation, and watershed area). Most candidate lakes have volumes proportional to and commensurate with their watershed area, consistent with precipitation as their primary source. However, other lakes have volumes that are anomalously large relative to their watershed areas, implying that groundwater may have been important in their filling. Candidate groundwater-sourced lakes are generally concentrated in the Arabia Terra region but also include the Eridania basin [Irwin, R.P., Howard, A.D., Maxwell, T.A., 2004a. J. Geophys. Res. 109, doi: 10.1029/2004JE002287. E12009; Irwin, R.P., Watters, T.R., Howard, A.D. Zimbelman, J.R., 2004b. J. Geophys. Res. 109, doi: 10.1029/2004JE002248. E09011] and several lakes near the dichotomy boundary. This areal distribution is broadly consistent with where groundwater should have reached the surface as predicted by current models. Both surface runoff and groundwater flow appear to have been important sources for lakes and lake chains, suggesting a vertically integrated hydrological system, the absence of a global cryosphere, and direct communication between the surface and subsurface hydrosphere of early Mars.

Development of a regional hydrologic soil model and application to the Beerze–Reusel drainage basin

The soil compartment is an important interface between the atmosphere and the subsurface hydrosphere. In this paper a conceptual approach for regional hydrologic soil modelling (RHSM) is presented, which provides two important qualities for modelling. First, the soil compartment is directly coupled to the atmosphere via the land surface and to the aquifers. Second, extremely fine (5 cm vertical) resolutions of the soil system can be realized at regional scales (several hundreds of km 2). This high-resolution modelling could be achieved by parallel computation techniques. The RHSM approach is applied to the Beerze–Reusel drainage basin, which belongs to the Meuse River basin. Moisture transport in the soil system was calculated with extremely high vertical resolution at a regional scale based on rainfall–evaporation data for the year 2000. As a result, highly resolved regional groundwater recharge pattern addressing the heterogeneity of soil systems could be determined.

Groundwater Monitoring at the Facilities of Oil and Gas Complex

The environmental aspects of the development of oil and gas deposits are considered. The methodological principles of the formation of a hydrogeological monitoring system in the general structure of comprehensive geoenvironmental monitoring of oil-and-gas facilities are discussed. The structure of comprehensive geoenvironmental monitoring and subsurface-hydrosphere monitoring is presented. It consists of observation, estimate, and forecast subsystems. Requirements are formulated to the source data that forms the basis, on which the observational network is designed; the state of the subsurface hydrosphere is assessed both at the stages of designing the facilities being examined and their monitoring system and during the process of operation of the facilities and systems of monitoring. Changes in the environment and subsurface hydrosphere as its component are predicted.

Lithological and Hydrogeochemical Implications of Ion Exchange in Sedimentary Basins: Evidence from the Volga–Ural Basin

Implications of ion exchange processes for the formation of lithological and hydrogeochemical systems under various thermobaric conditions of the subsurface hydrosphere are discussed on the basis of on-location, experimental, and thermodynamic studies. It is shown for the case of the Volga–Ural sedimentary basin that ion exchange interaction in the water–rock system bears a zonal character and is differentiated with depth. Exchange and adsorption processes are most efficient in the upper 500-m-thick supergene zone composed of terrigenous clayey rocks, where the HCO3–Na- and SO4–Na-waters with a mineralization reaching 20 g/dm3 are formed. In cata- and metagenetic zones at a depth of more than 1000–1500 m, these processes do not strongly affect the brine composition. Metasomatic dolomitization of limestones as an exchange adsorption process plays the crucial role in the formation of Cl–Ca-brines at that depth.

The Basic Principles and Recommendations for the Assessment and Mapping of the Degree of Groundwater Protection against Pollution

It is shown that the interaction between subsurface hydrosphere and other environmental components and the possible extent of its pollution through these components can be characterized by the degree of groundwater protection against pollution and can be represented on appropriate maps based on simple model estimates of pollutant movement through the lithosphere serving as a protection zone. The principles and methods used in evaluating and different-scale mapping of groundwater protection degree and their vulnerability with respect to pollutants with different toxicity are discussed.

The Role of Density-Driven Convection in the Formation of Hydrogeochemical Zonality in Artesian Basins

The main types of mass transfer in the subsurface hydrosphere are considered. Specific features of vertical hydrogeochemical zonality in the Volga–Ural Artesian Basin are discussed, and the history of its hydrogeological development is considered. The principal role in the formation of the zone of different-composition brines, dominating in the sedimentary cover, is shown to belong to the processes of halogenesis in the Early Permian and density-driven convection of mother brine from evaporite paleoreservoirs into underlying terrigenous–carbonate Paleozoic strata. The problems regarding the mechanism and lithologic–hydrogeochemical consequences of the density-driven convection in the subsurface hydrosphere in a sedimentary basin are considered.

Formation and Age of Brines in Solikamsk Depression

The chemical composition of the main types of brines in the area west of the Urals is studied. The brines involved are spatially and genetically associated with Permian halogen formations. The main role in the formation of chlorine–calcium brines, dominating the sedimentary cover in the basin, is shown to belong to the concentration convection of chlorine–magnesium salt-forming brine from the kungurskii evaporate paleo–water body into the underlying Paleozoic rocks and the subsequent metamorphization of the brine as a result of processes of metasomatic doomitization of carbonate rocks. Particular attention is paid to the condensation processes and the hydrogeochemical inversion in the subsurface hydrosphere of the region, which is associated with these processes. Estimates of the absolute age of brines based on the kinetic–geochemical technique are given.

Distribution of oxygen in the subsurface hydrosphere

Distribution of oxygen in the subsurface hydrosphere

Chemical inversion in the subsurface hydrosphere

A quite common nature of chemical inversion in subsurface hydrosphere is shown in examples of several oil- and gas-bearing regions of the USSR. In particular, when the data of sampling from deep wells of the Volgo-Urals, Mangyshlak, and Western Turkmenian regions were compared, it became obvious that the composite chemical profile of subsurface hydrosphere consists of a vertical alternation of three zones: of increasing (I-II-IIIa genetic types of subsurface waters), maximum (IIIb), and decreasing water mineralization (III'a-II'-I'). The depth of occurrence of the lower inversion branch of zonality depends on the geotectonic activity at depth. It is closer to the Earth's surface in regions of Alpine tectogenesis, whereas in regions of ancient folding it lies at great depths which have not yet been reached by most deep wells. The formation of the inversion zone in the Earth's crust is connected with penetration from below ascending demineralized fluids of sodium bicarbonate type (I'). The latter is due to the presence at great depths of large quantities of free carbonic acid which is involved in hydrolytic processes of decomposition of sodium-containing minerals and produces sodium-type waters.

Lunar Rilles and a Possible Terrestrial Analogue

CALCULATIONS by several authors suggest that the Moon, like the Earth, could not have retained a residue of its primordial atmosphere1–5. Gilvarry6–8, however, has considered the possibility of a lunar hydrosphere and of an early lunar atmosphere replenished, like that of the Earth, from within. On this theory the sinuous rilles (Figs. 1 and 2) might be ancient channel-scouring marks. One possibility is the melting of a frozen sub-surface hydrosphere by cometary impacts, allowing the material to flood the surface.

Thermal waters as a source for extraction of chemicals

In recent years much attention is being given in the USSR, as well as in a number of other countries, to the study of the mineral content of thermal waters which do constitute an important portion of subsurface hydrosphere. This interest finds its explanation in the fact of the possible utilization of such waters — either their heat, or valuable chemical components — for the purposes of national economy. Starting from the evidence available on naturally existing conditions for the origin and spatial distribution of thermal waters, it seems reasonable to examine the geothermal search-indices with the following implications taken into account. Only those areas or regions may be of potential geothermal importance, either in the field of balneology (with sulphurated, acid, radon-waters etc.), or in the commercial sphere (with iodine, bromine, boron lithium-bearing, potassium-bearing waters etc.), which are characterized by particular geological, thermal and geochemical features. Generally these areas are represented by folded belts or zones (characteristic) of recent or lately extinguished volcanic activity. These may be, again, mobile structural units associated with belts (foredeeps, intermontane and marginal troughs), and filled with volcanic-sedimentary or or normal sedimentary rocks. Chloride waters, rich in salts, and revealing high concentrations of bromine potassium, lithium and strontium are being formed because of halogen formations found throughout the sedimentary sequence. Concentration of bromine, strontium, lithium and rubidium is increasing with depth of occurrence of thermal waters and rising mineralization, while boron and iodine show a reverse regional dependence — their concentration goes down with depth and rising mineralization.