Electrical Earth Resistivity Research Articles

GORDON LYALL PAVER (1913–1988) AND 42ND GEOLOGICAL SECTION, SOUTH AFRICAN ENGINEER CORPS: MILITARY GEOLOGY AND GEOPHYSICS IN WORLD WAR II SUPPORTING BRITISH ARMY OPERATIONS: PART 1, THE EAST AFRICAN CAMPAIGN 1940–1941

ABSTRACT 42nd Geological Section of the South African Engineer Corps was a unique unit that supported British armed forces during World War II. It was co-founded and led for most of the war by Gordon Lyall Paver (1913–1988), one of the few ‘British’ officers serving specifically as geologists during the war to achieve the rank of major. Born in South Africa at Johannesburg and in his early years educated there at St. John's College, from 1926 Paver was educated in England, at Charterhouse School until admitted in 1931 to Pembroke College in the University of Cambridge, where he studied chemistry, geology and mineralogy. He graduated in 1934 and returned to South Africa, being appointed to the Geological Survey of South Africa as one of its first geophysicists and contributing to magnetometric and gravimetric surveys in the Transvaal region, expertise used in 1938 to 1940 to draft his thesis for a PhD degree (awarded in 1942). Although married in 1939 and briefly employed as a consultant geophysicist, in August 1940 Paver was one of the first three geoscientists to be mobilized as officers to found 42nd Geological Section, at Zonderwater near Pretoria in South Africa. After only a month's military training, at the end of September the Section and its vehicles deployed by rail and sea to a base near Nairobi in Kenya for operational service in East Africa, with ‘Acting Captain’ Paver as its Second-in-Command. Detachments from the Section were widely deployed in Kenya and later in Italian and British Somaliland (present-day Somalia) and also in Abyssinia (present-day Ethiopia) for surveys by means primarily of electrical earth resistivity but also vertical force magnetometer. These guided drilling of wells by another unit of the South African Engineer Corps to abstract potable groundwater— thereby facilitating troop concentrations and forward movements in arid or semi-arid regions during the ‘British’ Army's East African Campaign. Members of the Section also compiled geological maps of Kenya at scales of 1:1,000,000 and 1:2,000,000 and pioneered a military geological unit created within the East African Engineers that supported British forces in the region from 1941 to 1945. The Campaign drew to a victorious close during 1941 and, from the end of August, the Section was re-deployed northwards to a base near Cairo in Egypt. It continued to serve within the British Army's Middle East Command but with leadership now by Paver, promoted ‘Acting Major’ from 31 August and in December ‘mentioned in despatches’ for his earlier distinguished service in East Africa.

Monitoring shale gas resources in the Cooper Basin using magnetotellurics

The magnetotelluric (MT) method is introduced as a geophysical tool to monitor hydraulic fracturing of shale gas reservoirs and to help constrain how injected fluids propagate. The MT method measures the electrical resistivity of earth, which is altered by the injection of fracturing fluids. The degree to which these changes are measurable at the surface is determined by several factors, such as the conductivity and quantity of the fluid injected, the depth of the target interval, the existing pore fluid salinity, and a range of formation properties, such as porosity and permeability. From an MT monitoring survey of a shale gas hydraulic fracture in the Cooper Basin, South Australia, we have found temporal and spatial changes in MT responses above measurement error. Smooth inversions are used to compare the resistivity structure before and during hydraulic fracturing, with results showing increases in bulk conductivity of 20%–40% at a depth range coinciding with the horizontal fracture. Comparisons with microseismic data lead to the conclusion that these increases in bulk conductivity are caused by a combination of the injected fluid permeability and an increase in wider scale in situ fluid permeability.

Norman Rostoker

Norman Rostoker, a nuclear fusion innovator and, in his words, “somewhat a renegade” advocate of research independent of the US Department of Energy, died on 25 December 2014 in Irvine, California. At the time of his death, Tri Alpha Energy, the company he cofounded to advance work in field-reversed magnetic containment methods, was building its third-generation machine.Norman RostokerAIP ESVA, GIFT OF NORMAN ROSTOKERPPT|High resolutionBorn on 16 August 1925 in Toronto, Rostoker went to the University of Toronto, where he earned a BA in science in 1946 and a master’s degree in 1947. After receiving a DSc in physics from the Carnegie Institute of Technology in 1950, he worked there as a research physicist until 1953. His 1950 work on electrical resistivity of Earth, based on the Green function method, had widespread impact. Modern petroleum prospecting with low-frequency electromagnetic waves uses and expands on the physics in Rostoker’s work, and his Green function method was used in his later solid-state theory and in the foundation of plasma theory.In 1954 Rostoker added to what is now known as the Korringa-Kohn-Rostoker approximation, a Green function method still widely used in calculating the electronic band structure in solids. He broke ground on theories of the statistical mechanics of particles with Coulomb interactions and on the treatment of inhomogeneities, fluctuations, and cyclotron-radius effects in plasmas. Rostoker built on his solid-state work by translating the test-particle method into plasma physics, whereby a gas of charged particles is viewed as a group of “dressed” particles in which each one has its own shielding cloud. The concept simplifies basic property calculations and especially the particle-in-cell simulation approach.That foray into plasma physics led Rostoker into the practical side of plasma fusion research. He worked at the Armour Research Foundation and General Atomics before becoming a professor of physics at the University of California (UC), San Diego, in 1962. Starting in 1967 he was IBM Professor of Engineering at Cornell University, and in 1972 he joined the faculty at UC Irvine. He served as chair of the physics and astronomy department from 1973 to 1976.Rostoker believed that clean fusion should be an almost limitless, non- polluting energy source. Once he had developed the theoretical foundation, he began working to make the technology a reality. He had a gift for being able to apply theory to develop innovative fusion reactor technology.Among the first generation of fusion energy trailblazers, Rostoker saw early on the simplicity of field-reversed magnetic confinement geometries. Magnetic “bottles” are effective if the field lines do not penetrate solid surfaces but instead bend and close on themselves. Tokamaks implement the confining field in a toroidal chamber but require a current inside the plasma to give the field a helical twist. In field-reversed configurations, field lines are closed, so they provide good confinement, but the chamber is cylindrical, so it is easy to construct and maintain. The anomalous transport characteristic of tokamaks can be avoided, and a compact reactor design becomes viable.At Cornell and UC Irvine, Rostoker pursued the use of collective fields to accelerate ions in plasma. That work inspired a generation of students, some of whom went on to develop innovative plasma acceleration methods. Rostoker meanwhile combined accelerator physics with the plasma physics of a field-reversed geometry for use in a fusion reactor; in that alone he held 27 US patents. His laboratory team focused on devising new approaches to the central fusion problems and was able to translate theory into hardware.Fusion demands extremely high energy ions. In his most significant insight, Rostoker proposed that high-energy, large-orbit particles, such as those in accelerators, can “ride over” disruptive plasma turbulence and average their effects to nearly zero. With that approach, now known as Norman’s conjecture, researchers can thus get around plasma instabilities that interfere with other designs. Rostoker also wanted to use the boron–proton fusion reaction to devise a fusion reactor whose surrounding structure is not degraded by neutron capture. In 1998 Rostoker and his group at UC Irvine spun off Tri Alpha Energy to carry the efforts further. Unable to gain enough funding from the Department of Energy, Rostoker thereafter kept the company independently funded. He instituted a chair in applied physics in 2012 at UC Irvine.Rostoker was boundlessly resourceful in his humor and was able to soften even the most sullen of people at the tensest of times. He also showed unlimited generosity to his students, whom he attracted to UC Irvine from around the world. He personally picked up one of us (Tajima), fresh from Japan, at the John Wayne Airport in September 1973.© 2015 American Institute of Physics.

Electrical earth resistivity surveying for delineating the characteristics of ground water in a semi‐arid region in the Khanasser Valley, northern Syria

AbstractA resistivity survey is conducted in Khanasser Valley, a semi‐arid region in northern Syria, to delineate the characteristics of ground water affected by the salt‐water intrusion related to Al‐Jaboul Sabkha. Existing wells were used to measure salinity and conductivity of water samplings. Vertical electrical sounding was carried out near the existing wells. The combination of resistivity and hydrogeological data enables the establishment of empirical relationships between earth resistivity, water resistivity, and the amount of total dissolved solids. These relationships are then used in order to derive salinity maps for electrode spacings of 70, 100, and 150 m. The distribution of fresh, brackish and salt‐water zones and their variations in space along two longitudinal profiles (LP1 and LP2) are established through converting subsurface depth–resistivity models into different ground‐water areas. The constructed ground‐water area maps allow interfaces between different water zones to be determined. Copyright © 2006 John Wiley & Sons, Ltd.

Synchronous precursors in the electrical earth resistivity and the geomagnetic field in relation to an earthquake near the Yamasaki fault, Southwest Japan.

Precursory changes both in th electrical earth resistivity and in the geomagnetic total force gradient were clearly observed in relation to the earthquake of M 5.6 which occurred near the Yamasaki fault on May 30, 1984. The observation site was at a distance of several kilometers from the epiceter. The precursors were recognized about 60-70 days before the event. First the resistivity gradually decreased during 10 days by 30% of its ordinary value. After keeping a low level for about 50 days, the resistivity began to increase, exceeding the ordinary value 2 days before the shock, and attained to a maximum of 400% after the shock. The extremely large value returned to its ordinary value within two weeks after the event. The geomagnetic total force gradient also showed about 10% increase synchronously with the resistivity change. Almost 2 days after the shock, the gradient recovered to its ordinary value. No coseismic change was recognized. Other precursor like changes of the resistivity possibly associated with several earthquakes in southwest Japan were also detected at the same observation site within the last year. We consider that the resistivity change may be caused by a small amount of change in the water content within the rocks or fissures around the fault and that the fault region is a place particularly sensitive to tectonic stress changes. A resistivity structure model to account for the observed precursors will be presented.

Investigation of a Damsite Utilizing Drill-hole, Down-hole Geophysical and Surface Geophysical Data

Research Article| January 01, 1978 Investigation of a Damsite Utilizing Drill-hole, Down-hole Geophysical and Surface Geophysical Data ROBERT B. JOHNSON; ROBERT B. JOHNSON Robert B. Johnson is with the Dept. of Earth Resources, Colorado State University, Fort Collins, Colorado. Search for other works by this author on: GSW Google Scholar LYNN A. JOHNSON LYNN A. JOHNSON Lynn A. Johnson is with the U.S. Bureau of Reclamation, Denver, Colorado. Search for other works by this author on: GSW Google Scholar Environmental & Engineering Geoscience (1978) xv (3): 285–294. https://doi.org/10.2113/gseegeosci.xv.3.285 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation ROBERT B. JOHNSON, LYNN A. JOHNSON; Investigation of a Damsite Utilizing Drill-hole, Down-hole Geophysical and Surface Geophysical Data. Environmental & Engineering Geoscience 1978;; xv (3): 285–294. doi: https://doi.org/10.2113/gseegeosci.xv.3.285 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEnvironmental & Engineering Geoscience Search Advanced Search Abstract The proposed site of an earth dam for the Bureau of Reclamation's Nebraska Mid-State Project presents a complex foundation problem involving alluvial fill in a buried channel cut in similar sediments of Tertiary age. Three drill holes provided control of stratigraphy, material types and unit thicknesses. Electric and gamma-ray logs were run to obtain geophysical data for the materials encountered. Surface geophysics was employed to determine the lateral extent, changes in materials and thickness, and channel configuration of the units noted in the drill-hole and geophysical log data.The physical properties of the materials restricted the use of surface geophysics. Electrical earth resistivity provided the only means of separating and mapping the units on the basis of electrical contrasts provided by the electric logs. Gamma-ray log data served to reinforce electric log and drill-hole correlations.Empirical interpretation of total resistivity and Lee partitioning curves were employed for correlation of resistivity and drill-hole data and for interpretation of lateral changes and extrapolation of subsurface conditions between drill holes. Curve fitting techniques provided a means of obtaining a geophysical overview of the survey uncomplicated by minor unit differences.The integrated use of drill-hole, geophysical well log and surface geophysical data permitted development of a materials profile along the section of dam involved. Further drilling may now be done at those sites shown to present critical interfacing of potentially troublesome materials. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.