scholarly journals Temporal variations of methane concentration and isotopic composition in groundwater of the St. Lawrence Lowlands, eastern Canada

2017 ◽  
Vol 26 (2) ◽  
pp. 533-551 ◽  
Author(s):  
Christine Rivard ◽  
Geneviève Bordeleau ◽  
Denis Lavoie ◽  
René Lefebvre ◽  
Xavier Malet
Keyword(s):  
Isotopic Composition ◽  
Methane Concentration ◽  
Temporal Variations ◽  
Eastern Canada

Hydrogeochemical temporal variations related to changes of seismic activity at Tenerife, Canary Islands

2021 ◽  
Author(s):  
Cecilia Amonte ◽  
María Asensio-Ramos ◽  
Gladys V. Melián ◽  
Nemesio M. Pérez ◽  
Eleazar Padrón ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Seismic Activity ◽  
Temporal Variations ◽  
Total Alkalinity ◽  
Molar Ratio ◽  
Sampling Point ◽  
Volcanic System ◽  
Mean Values ◽  
Isotopic Analyses ◽  
San Fernando

<p>The oceanic active volcanic island of Tenerife (2034 km<sup>2</sup>) is the largest of the Canarian archipelago. There are more than 1,000 galleries (horizontal drillings) in the island, which are used for groundwater exploitation and allow reaching the aquifer at different depths and elevations. During a two-year period (July 2016 to July 2018), a hydrogeochemical study was carried out in two galleries on Tenerife (Fuente del Valle and San Fernando) for volcanic monitoring purposes with weekly sampling. Physicochemical parameter of water, such us temperature (ºC), pH and electrical conductivity (E.C., µS·cm<sup>-1</sup>), were measured in-situ at each sampling point and chemical/isotopic composition of the water determined later in the laboratory.</p><p>Temperature values showed mean values of 28.1 ºC and 19.0 ºC for Fuente del Valle and San Fernando galleries, respectively. According to the average pH values, which were 6.30 for Fuente del Valle and 7.13 for San Fernando, and based on the chemical composition, both galleries are sodium-bicarbonate (Na-HCO<sub>3</sub>) type. E.C. values in both galleries presented high ranges, with mean values of 975 and 1648 µS·cm<sup>-1</sup> for Fuente del Valle and San Fernando, respectively. The total alkalinity mean value of groundwater from Fuente del Valle gallery was 11.3 mEq·L<sup>-1</sup> HCO<sub>3</sub><sup>-</sup>, while that from San Fernando was 17.3 mEq·L<sup>-1</sup> HCO<sub>3</sub><sup>-</sup>. The SO<sub>4</sub><sup>2-</sup>/Cl molar ratio was 0.59 and 3.4 for the samples from Fuente del Valle and San Fernando galleries, respectively.</p><p>The δ<sup>18</sup>O and δD isotopic analyses showed a meteoric origin of groundwaters, with mean values of -6.2‰ and -26‰ vs. VSMOW for Fuente del Valle and -6.2‰ and -21 ‰ vs. VSMOW for San Fernando. The isotopic data showed a strong interaction with endogenous gases such as CO<sub>2</sub>, H<sub>2</sub>S, H<sub>2</sub>, etc. Regarding the isotopic composition of total dissolved carbon species, expressed as δ<sup>13</sup>C<sub>TDIC</sub>, average values of -0.17‰ and 0.26‰ were obtained for Fuente del Valle and San Fernando galleries, respectively. These results show an endogenous origin CO<sub>2</sub> signature, heavier for Fuente del Valle gallery groundwater compared to that of San Fernando.</p><p>Groundwater physicochemical parameters exhibited stable values throughout the study period, while significant temporal variations were observed in the total alkalinity, SO<sub>4</sub><sup>2-</sup>/Cl<sup>-</sup> molar ratio, δ<sup>18</sup>O and δD. Changes in isotopic ratios coincided with variations observed in the alkalinity and the SO<sub>4</sub><sup>2-</sup>/Cl<sup>-</sup> molar ratio. On October 2, 2016, a seismic swarm of long-period events was recorded on Tenerife followed by a general increase of the seismic activity in and around the island. A correlation was observed between some hydrogeochemical parameters in the groundwaters of the galleries, related to observed changes of the seismic activity. This study demonstrates the suitability of monitoring the chemical and isotopic composition of groundwater from Fuente del Valle and San Fernando galleries, as they are sensitive to changes in volcanic activity on Tenerife island. The study of groundwaters associated to a volcanic system can provide information about the magmatic gas input in the aquifer, modelling how the groundwaters flow through the edifice, and offer important geochemical information that could herald a future eruption.</p>

Hydrodynamic conceptual model of groundwater in the headwater of the Rio de Oro, Santander (Colombia) by geochemical and isotope tools

2020 ◽  
Vol 20 (4) ◽  
pp. 1567-1579
Author(s):  
M. Cetina ◽  
J-D. Taupin ◽  
S. Gómez ◽  
N. Patris
Keyword(s):  
Isotopic Composition ◽  
Conceptual Model ◽  
Temporal Variations ◽  
High Mountain ◽  
Secondary Porosity ◽  
Water Geochemistry ◽  
Carbonate Formation ◽  
Mountain System ◽  
Geological Formation ◽  
Primary Porosity

Abstract Metamorphic, igneous and sedimentary rocks, with low to no primary porosity, outcrop in the La Moza micro-basin stream (headwater of the Rio de Oro). In this high mountain system, water isotopic composition of rainwater, water isotopes and geochemistry of groundwater (springs) and surface water were determined. Groundwater flows are associated to phreatic aquifers in relationship with secondary porosity generated by fracturing, which is increased by dissolution processes in case of carbonate formation producing karstic systems and by the weathering phenomenon mainly affecting granodioritic rocks. Water geochemistry shows low to medium electrical conductivity (EC) depending on the geological formation, but a unique calcium bicarbonate facies. Spring water EC shows limited temporal variations. The isotopic composition of spring indicates a meteoric origin, local infiltration and groundwater flows with low residence time. A conceptual model of the recharge zone is proposed that crosses the surface watershed and covers part of the adjacent Rio Jordán basin, where the Berlin Paramo is located.

Temporal Variations of Isotopic Composition of Glacier-River Water During Summer: Observations at Austre Okstindbreen, Okstindan, Norway

1988 ◽  
Vol 34 (118) ◽  
pp. 309-317 ◽  
Author(s):  
Wilfred H. Theakstone
Keyword(s):  
Isotopic Composition ◽  
River Water ◽  
Temporal Variations ◽  
Surface Melting ◽  
Base Flow ◽  
Strongly Correlated ◽  
Drainage Systems ◽  
Fine Weather ◽  
Air Temperatures ◽  
Glacier Ice

AbstractThe isotopic composition of river water discharging from the Norwegian glacier, Austre Okstindbreen, in summer varies on both daily and longer-term scales. Most δ18o values of samples from the principal river are within the range −12.5 to −14.0‰). Because new snow tends to be relatively depleted of 8180, water leaving the glacier early in the summer has low δ18O values. Subsequently, values rise as contributions of old snow, glacier ice, and their melt waters, which are isotopically heavier (median δ18O values generally above −12.0‰) dilute the δ18O depleted base-flow component of discharge, a mixture of waters with different histories of formation, storage, and transit. Accumulation-area melting contributes significantly to river discharge. Towards the end of the summer, as surface melting declines, δ18O values tend to fall. Between-year differences of within-summer trends reflect differences of development of the glacier’s drainage systems. The drainage systems are affected by outbursts from a glacier-dammed lake. During fine weather, δ18ovariations follow the diurnal cycle of surface melting: they are strongly correlated with, but lag behind, air temperatures. Perturbations during rainfall cannot be explained simply in terms of the isotopic composition of the precipitation, since low values may be associated with isotopically heavy rainfall. Displacement of water previously stored within or below the glacier may account for the anomaly. Contrasts of composition characterize different rivers leaving the glacier, because the relative contributions of various water sources differ.

Influence of temporal variations in water chemistry on the Pb isotopic composition of rainbow trout (Oncorhynchus mykiss)

2005 ◽  
Vol 350 (1-3) ◽  
pp. 204-224 ◽  
Author(s):  
Jerry R. Miller ◽  
Jamie B. Anderson ◽  
Paul J. Lechler ◽  
Shannon L. Kondrad ◽  
Peter F. Galbreath ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Isotopic Composition ◽  
Water Chemistry ◽  
Temporal Variations ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Pb Isotopic Composition

scholarly journals Also tropical freshwater ostracods show a seasonal life cycle

2017 ◽  
Author(s):  
Juliane Meyer ◽  
Claudia Wrozyna ◽  
Albrecht Leis ◽  
Werner Piller
Keyword(s):  
Life Cycle ◽  
Environmental Factors ◽  
Isotopic Composition ◽  
Temporal Variations ◽  
South Florida ◽  
Population Variation ◽  
Instrumental Data ◽  
Mean Values ◽  
Isotopic Signatures ◽  
Isotopic Compositions

Abstract. Isotopic signatures of ostracod shells became common proxies for the reconstruction of paleo-environmental conditions. Their isotopic composition is the result of the composition of their host water and the phenology and ecology of the target species. The sum of spatial and temporal variations from environmental factors in the species habitat defines the maximum isotopic variation of a population during the time of their shell formation. Here we present isotopic signatures (δ18O, δ13C) of living Cytheridella ilosvayi (Ostracoda) and chemical and isotopic compositions of 14 simultaneously sampled freshwater habitats in South Florida and instrumental data of the region. The chemical and isotopic compositions of the selected sites characterize the different habitats and show the influence of the source water, biological activity and the duration of exposure to the surface. Isotopic signatures of C. ilosvayi shells correlate well with the isotopic composition of their host waters. Within-sample variability of repeated isotopic measurements of ostracod shells reflect habitat dependent ranges and indicate temperature and the δ18O composition of precipitation (δ18Oprec) as regional environmental factors responsible for the population variation. Instrumental data of water temperature and δ18Oprec were used to calculate the monthly variation of a theoretical calcite in rivers of Florida showing distinct seasonal variations in values and ranges. Different configurations of the theoretical calcite were compared to the within-sample variability to identify possible calcification periods of C. ilosvayi. For a plausible calcification period the ostracod isotopic range has to correlate with mean values of the theoretical calcite with a slight positive offset (vital effect) and the extension of the theoretical calcite range. The tested model suggests a seasonal calcification period of C. ilosvayi in early spring. The surprising seasonality of a tropical ostracod life cycle is probably coupled to the hydrologic cycle of Florida. The results of this study contribute to the application of ostracod isotopes in modern calibration studies and their potential use in paleontology.

scholarly journals Temporal and spatial hydrogeochemical evolution and lead isotopic composition of a contaminated stream of Taxco, Guerrero, Mexico

2020 ◽  
Vol 37 (1) ◽  
pp. 64-79 ◽  
Author(s):  
Natasha Mylena Quevedo-Castañón ◽  
Oscar Talavera Mendoza ◽  
Sergio Adrián Salgado-Souto ◽  
Joaquin Ruiz ◽  
Azucena Dótor-Almazán ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Toxic Elements ◽  
Mine Drainage ◽  
Electrical Conductance ◽  
Temporal Variations ◽  
Minor Role ◽  
Isotopic Study ◽  
Southern Mexico ◽  
Mining Sites ◽  
A Minor

Discharge of Acid Mine Drainage (AMD) produced within flooded mines is a major environmental issue in most polymetallic mining sites severely impacting nearby natural resources and producing a serious menace to the ecosystem and humans. The identification of both natural and anthropological factors influencing the bioavailability of toxic elements is relevant in revealing their behavior but also in the design of strategies for mitigating adverse effects to the environment. For these purposes, we carried out a spatial and seasonal hydrogeochemical (total and soluble contents) and a lead isotopic study of the AMD of the Xochula stream in the mining region of Taxco, Guerrero, in southern Mexico. The AMD is produced by the periodic discharge from the flooded Guerrero mine to the Xochula stream and is characterized by low to moderate pH, high sulfate, and high total and soluble metal contents. The AMD shows significant spatial but smaller temporal variations. Flow of AMD through a culvert made of concrete produces the most important chemical changes recorded regardless of the time of year significantly decreasing the electrical conductance and the concentration of total and soluble potentially toxic elements. Distribution of metals and As between dissolved and particulate-bound species is pH-controlled. Due to the short interaction time between the AMD and bedrock and the formation of coatings, lithology plays a minor role in neutralization, whereas mixing of AMD with freshwater is only significant in the less acidic segment of the stream. Neutralization of AMD entails a significant decrease of the concentration of both total and soluble metals and As and chemical speciation indicates that oxides, carbonates and sulfates are the reactive phases. The Pb isotopic composition reveals that metals derive from the Taxco ore deposit and that AMD is influenced by rocks of the Morelos and Taxco Schist formations.

scholarly journals Isotope hydrology and water sources in a heavily urbanised stream

2021 ◽  
Author(s):  
Christian Marx ◽  
Doerthe Tetzlaff ◽  
Reinhard Hinkelmann ◽  
Chris Soulsby
Keyword(s):  
Isotopic Composition ◽  
Agricultural Land ◽  
Stream Water ◽  
Treatment Plant ◽  
Temporal Variations ◽  
Water Sources ◽  
Stable Water Isotopes ◽  
Runoff Generation ◽  
Urban Catchments ◽  
Urban Storm

Complex networks of both natural and engineered flow paths control the hydrology of streams in major cities through spatio-temporal variations in connection and disconnection of water sources. We used spatially extensive and temporally intensive sampling of water stable isotopes to disentangle the hydrological sources of the heavily urbanized Panke catchment (≈ 220 km²) in the north of Berlin, Germany. The isotopic data enabled us to partition stream water sources across the catchment using a Bayesian mixing analysis. The upper part of the catchment streamflow here is dominated by groundwater from gravel aquifers underlying surrounding agricultural land. In dry summer periods, streamflow becomes intermittent; possibly as a result of local groundwater abstractions. Urban storm drainage is also an important part of runoff generation, dominating the responses to precipitation events. Although this dramatically changes the isotopic composition of the stream, it only accounts for 10-15% of annual streamflow. Moving downstream, subtle changes in sources and isotope signatures occur as catchment characteristic vary and the stream is affected by different tributary inflows. However, effluent from a wastewater treatment plant (WWTP) serving 700,000 people dominates the stream in the lower catchment where urbanisation effects are more dramatic. The associated increase in sealed surfaces downstream also reduces the relative contribution of groundwater to streamflow. The volume and isotopic composition of storm runoff is again dominated by urban drainage. As a result, only about 10% of annual runoff in the lower catchment comes from urban storm drains. The study shows the potential of stable water isotopes as inexpensive tracers in urban catchments that can provide a more integrated understanding of the complex hydrology of major cities. This offers an important evidence base for guiding the plans to develop and re-develop urban catchments to protect, restore and enhance the ecological and amenity value of these important resources.

scholarly journals Climate Response of Oxygen Isotopic Compositions in Tree-Ring Cellulose in Java: Evaluation Using a Proxy System Model

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 310
Author(s):  
Ryo Hisamochi ◽  
Yumiko Watanabe ◽  
Naoyuki Kurita ◽  
Takahiro Tagami
Keyword(s):  
Relative Humidity ◽  
Isotopic Composition ◽  
Tree Ring ◽  
Temporal Variations ◽  
Oxygen Isotopic Composition ◽  
System Model ◽  
Climate Response ◽  
Growing Period ◽  
Oxygen Isotopic ◽  
Tree Ring Cellulose

Tree-ring cellulose oxygen isotopic composition (δ18O) is controlled by several hydrological factors such as precipitation, relative humidity, and temperature. A proxy system model can reveal how these factors affect tree-ring cellulose δ18O. In this study, to identify a key control on tree-ring cellulose δ18O variations, we performed model calculation of year-to year variation of tree-ring cellulose δ18O of Javanese teak in Indonesia from 1960 to 1998. Our model results reasonably reproduce the observed δ18O values and their temporal variations (r = 0.6; p < 0.001). Moreover, the sensitivity test shows that the cellulose δ18O values are sensitive to the teak growing period. The simulation result with earlier or later shifts of the growing period captured the amplitude of observed δ18O variations over 39 years. These results indicate that the tree-ring cellulose δ18O of Javanese teak might be influenced by a subtle shift of the intra-annual growing period.

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