Shallow Magnetic Induction Measurements for Delineating Near-Surface Hot Groundwater Sources in Alaskan Geothermal Areas

1983 ◽  
Vol 105 (2) ◽  
pp. 156-161 ◽  
Author(s):  
T. E. Osterkamp ◽  
K. Kawasaki ◽  
J. P. Gosink
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Induction ◽  
Hot Springs ◽  
Measured Temperature ◽  
Conductivity Data ◽  
Induction Method ◽  
Near Surface ◽  
Saline Groundwater ◽  
Geophysical Surveys ◽  
Conductivity Anomalies

Variations in the electrical conductivity of a soil and water system with temperature and salt concentration suggest that a soil containing hot and/or saline groundwater may be expected to have a higher conductivity compared to a cooler and/or less saline system. Temperature and conductivity surveys were carried out at Pilgrim Springs, on the Seward Peninsula, and at Chena Hot Springs, near Fairbanks, to test the use of a magnetic induction method (which measures electrical conductivity) for delineating near-surface hot groundwater sources in geothermal areas surrounded by permafrost. Comparison of the temperature data and conductivity data from these surveys demonstrates that the conductivity anomalies, as measured by the magnetic induction method, can be used to define the precise location of hot groundwater sources in these geothermal areas with the higher temperatures correlating with higher values of conductivity. Magnetic induction measurements of conductivity can also be used to define the lateral extent of the thawed geothermal areas (used for calculating the stored energy) in permafrost terrain. The utility of these magnetic induction measurements of conductivity for reconnaissance geophysical surveys of geothermal areas is that a much greater density of data can be obtained in a shorter time in comparison with shallow temperature measurements. In addition, it is simpler, cheaper and easier (physically) to obtain the data. While conductivity anomalies can result from other than hot and/or saline groundwater, these conductivity data, when coupled with a few measured temperature profiles and groundwater samples, should result in reliable reconnaissance level geophysical surveys in Alaskan geothermal areas.

A Reconnaissance Study of the Hydrothermal Characteristics of Pilgrim Springs, Alaska

1984 ◽  
Vol 106 (1) ◽  
pp. 96-102 ◽  
Author(s):  
T. E. Osterkamp ◽  
J. P. Gosink
Keyword(s):  
Electrical Conductivity ◽  
Ground Water ◽  
Water Flow ◽  
Saline Water ◽  
Hot Water ◽  
Geothermal System ◽  
Measured Temperature ◽  
Conductivity Measurements ◽  
Ground Water Flow ◽  
Near Surface

A reconnaissance level study of the Pilgrim Springs geothermal system was conducted to determine the near-surface thermal regime and to obtain information on the ground water flow regime within the thawed ground area. Measurements included soil temperatures, apparent electrical conductivity of the soil, electrical conductivity and temperature in the Pilgrim River, saturated hydraulic conductivity of the soil and ground water flow characteristics (direction and velocity). In addition the size, number and characteristics (geometry, direction of flow) of near-surface convective plumes were investigated. Measured temperature profiles were used to estimate ground water flow velocities. There are approximately 2–3 km2 of thawed ground surrounded by permafrost on the order of 100 m in thickness. The highest temperatures were found in the southwest quadrant of the thawed area where a pool of ground water at ≈ 92°C exists at 14–32 m below the ground surface. Temperature measurements suggest that water in the pool is flowing laterally and vertically. Temperature and electrical conductivity measurements suggest that this pool of water underlies most of the thawed ground area although the possibility of several, unconnected sources of hot water and multiple pools has not been ruled out. Conductivity measurements suggest that hot and/or saline water rises in convective plumes from the pool at about 40–60 sites. The Pilgrim River appears to be heated by heat transfer from the geothermal area. Saline ground water enters the Pilgrim River, probably through its bed, increasing the conductivity of the river water.

scholarly journals An evaluation of water quality at Sandhill Wetland: implications for reclaiming wetlands above soft tailings deposits in northern Alberta, Canada

2021 ◽  
Author(s):  
Jeremy A. Hartsock ◽  
Jessica Piercey ◽  
Melissa K. House ◽  
Dale H. Vitt
Keyword(s):  
Water Quality ◽  
Electrical Conductivity ◽  
Surface Water ◽  
Water Chemistry ◽  
Water Quality Monitoring ◽  
Total Alkalinity ◽  
Near Surface ◽  
Water Quality Guidelines ◽  
Quality Guidelines ◽  
Annual Water

AbstractThe experimental Sandhill Wetland is the first permanent reclamation of a composite tailings deposit, and annual water quality monitoring is of specific interest for evaluating and predicting long-term reclamation performance. Here, we present water chemistry monitoring data obtained from Sandhill Wetland (years 2009–2019) and compare results to twelve natural reference wetlands and to environmental quality guidelines for Alberta surface waters. By comparing water quality at Sandhill Wetland and natural sites to established guidelines, we can begin to document the natural background water quality of wetlands in the region and examine if guideline exceedances are seen in natural undisturbed environments, or appear only at active reclamation sites. At Sandhill Wetland the dominant ions in near-surface water were bicarbonate, sulfate, chloride, sodium, calcium, and magnesium. Since the first growing season concentrations for these ions have increased annually, causing concurrent increases in electrical conductivity. In year 2019, water chemistry at Sandhill Wetland was most comparable to regional saline fens, systems that exhibit elevated electrical conductivity and high sodicity. Near-surface water at Sandhill Wetland exceeded water quality guidelines for three substances/properties (dissolved chloride, iron, and total alkalinity) in the most recent year of monitoring. The saline fen natural sites also exceeded water quality guidelines for the same chemical substances/properties, suggesting guideline exceedances are a norm for some natural wetland site types in the region. Of note, in each year of monitoring at Sandhill Wetland, dissolved organic compounds evaluated in sub- and near-surface water were below detection limits.

Electrical conductivity anomalies in the earth

1978 ◽  
Vol 3 (3) ◽  
pp. 225-253 ◽  
Author(s):  
Yoshimori Honkura
Keyword(s):  
Electrical Conductivity ◽  
The Earth ◽  
Conductivity Anomalies

Numerical Simulation of MHD Rectangular Duct Flow with FCI Based on Magnetic Induction Method

2012 ◽  
Vol 452-453 ◽  
pp. 344-347
Author(s):  
Tian Neng Xu ◽  
Jie Mao ◽  
Hua Chen Pan
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Liquid Metal ◽  
Magnetic Induction ◽  
Metal Flow ◽  
Duct Flow ◽  
Rectangular Duct ◽  
Induction Method ◽  
Pressure Equalization ◽  
Liquid Metal Flow

In dual-coolant and self-cooled blanket concepts, the magnetohydrodynamic (MHD) pressure drop is a key point that should be considered. In order to reduce the high MHD drop, it requires an understanding of the liquid metal flow in rectangular duct with FCI. In this paper, two cases that have different pressure equalization slot widths were simulated based on MHD module of FLUENT. It is found that with different widths of pressure equalization slot, velocity distribution and pressure drop changes a lot.

The Double Magnetic Induction Method for Measuring Eye Movement - Results in Monkey and Man

1984 ◽  
Vol BME-31 (5) ◽  
pp. 419-427 ◽  
Author(s):  
Lo J. Bour ◽  
Jan A. M. Van Gisbergen ◽  
Jan Bruijns ◽  
Fenno P. Ottes
Keyword(s):  
Eye Movement ◽  
Magnetic Induction ◽  
Induction Method

Surveying Batavia’s Graveyard: Geophysical controlled experiments and subsurface imaging of archaeological sites on an Indian Ocean coral island

Geophysics ◽  
2017 ◽  
Vol 82 (4) ◽  
pp. B147-B163 ◽  
Author(s):  
Jeffrey Shragge ◽  
David Lumley ◽  
Nader Issa ◽  
Tom Hoskin ◽  
Alistair Paterson ◽  
...  
Keyword(s):  
Sea Water ◽  
Controlled Experiments ◽  
Near Surface ◽  
Survey Techniques ◽  
Geophysical Surveys ◽  
Archaeological Materials ◽  
Coral Island ◽  
Water Saturated ◽  
Ground Penetrating ◽  
Geophysical Anomalies

We conducted geophysical surveys on Beacon Island in the Houtman Abrolhos archipelago offshore Western Australia, to investigate areas of archaeological interest related to the 1629 Batavia shipwreck, mutiny, and massacre. We used three complementary near-surface geophysical survey techniques (total magnetic intensity, electromagnetic induction mapping, and ground-penetrating radar) to identify anomalous target zones for archaeological excavation. Interpreting near-surface geophysical anomalies is often complex and nonunique, although it can be significantly improved by achieving a better understanding of site-specific factors including background conditions, natural variability, detectability limits, and the geophysical response to, and spatial resolution of, buried targets. These factors were not well-understood for Beacon Island nor indeed for the Australian coastal environment. We have evaluated the results of controlled experiments in which we bury known targets at representative depths and analyze the geophysical responses in terms of an ability to detect and resolve targets from natural background variability. The maximum depth of detectability of calibration targets on Beacon Island is limited to approximately 0.5 m due to significant variations in background physical properties between a thin ([Formula: see text]) and highly unconsolidated dry sand, shell, and coral layer of variable thickness overlying a sea-water-saturated sandy half-space. Our controlled measurements have implications for calibrating and quantifying the interpretation of geophysical anomalies in areas of archaeological interest, particularly in coastal and sandy-coral island environments. Our geophysical analyzes contributed to the discovery of archaeological materials and five historical burials associated with the 1629 Batavia shipwreck.

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