Development of a light-weight low cost self potential unit

A lightweight, low cost self-potential unit has been developed using solid state components. The parts for the basic unit including batteries, copper sulfate pots, and hookup wire costs approximately $70.00. The device is instant reading and weighs two pounds. The batteries used have a shelf life of ten years and an estimated operation life (based on continuous use for ten hours per day) of sixty days. This instrument was developed specifically for the Alaskan prospector who is concerned with weight and cost of field instrumentation.The staff and faculty of the Mineral Industry Research Laboratory is proud to have sponsored the research which has led to this report by Kenneth L. Zonge, Assistant Professor of Electrical Engineering, Department of Electrical Engineering and part time employee of the Geophysical Institute, University of Alaska. This project was developed through consultation with Mr. Lawrence E. Heiner, Assistant Mineral Engineer, Mineral Industry Research Laboratory. Refinement in design of a self potential unit used in a geophysical prospecting technique by prospectors in their search for economic mineral deposits truly conforms with the major objective of the Laboratory - that of assisting in the development of the mineral resources of Alaska. Thus, through the piercing eyes of science and mineral engineering research, hidden deposits of minerals will be found that will allow further increases in the economy of the community, state and nation. E. H. Beistline, Dean, College of Earth Sciences, and Mineral Industr

Geophysical tomography in engineering geology: an overview

An overview of the tomographic interpretation method in engineering geophysics is presented, considering the two approaches of the deterministic tomography inversion, developed for rock elasticity analysis, and the probability tomography imaging developed in the domain of potential fields methods. The theoretical basis of both approaches is shortly outlined before showing a laboratory and a field application.Comment: 4 pages, 6 figures. Invited lecture at the 7th International Congress of the Brazilian Geophysical Society, Salvador, Bahia, Brazil, 28-31 October 200

Estimating the maximum possible earthquake magnitude using extreme value methodology: the Groningen case

The area-characteristic, maximum possible earthquake magnitude $T_M$ is required by the earthquake engineering community, disaster management agencies and the insurance industry. The Gutenberg-Richter law predicts that earthquake magnitudes $M$ follow a truncated exponential distribution. In the geophysical literature several estimation procedures were proposed, see for instance Kijko and Singh (Acta Geophys., 2011) and the references therein. Estimation of $T_M$ is of course an extreme value problem to which the classical methods for endpoint estimation could be applied. We argue that recent methods on truncated tails at high levels (Beirlant et al., Extremes, 2016; Electron. J. Stat., 2017) constitute a more appropriate setting for this estimation problem. We present upper confidence bounds to quantify uncertainty of the point estimates. We also compare methods from the extreme value and geophysical literature through simulations. Finally, the different methods are applied to the magnitude data for the earthquakes induced by gas extraction in the Groningen province of the Netherlands

Investigation Of Device For Geophysical Exploration At Shallow Depth

The article presents the results of the development of the echolocation device for geophysical exploration at shallow depth. The principle of operation, block diagram and time diagrams of the echolocation device for geophysical exploration at shallow depths are outlined. The urgency of developing an echolocation device for geophysical exploration at shallow depth is revealed in the conditions of a lack of mineral resources, the need to replenish them with the help of discovering new deposits.It is analyzed that under the action of a shock wave, multi-frequency harmonic damped seismic waves are excited to the earth\u27s surface, the frequency band of which is 1-200 Hz.When detonation generators are used to control the earth\u27s crust, the duration of the impact pulse is on the order of one millisecond and the frequency range at 0.5 from the maximum amplitude of the echo signals is 20-400 Hz, which allows using higher-frequency harmonic components of echo signals to determine and classify the object at depth up to 100 m.Echolocation device for geophysical exploration is intended for detection and primary classification of objects by their acoustic rigidity and can be used for geophysical exploration at shallow depths (up to 100.0 m)

A study of the compound evaluation for geophysical explorations by self-organizing maps

In Japan, in the high economic growth period in 1960’s, a great number of cutting ground and embankment slopes were formed to construct many roads. They have been aging now, it is important to estimate the health of them and maintain effectually. So, in situs, we usually carry out many kinds of the geophysical exploration. However, there is not the technique to compound and interpret the result of each geophysical exploration in a numerical formula of the engineering now. Therefore, we notice to self-organizing maps (SOM) used widely in a field of the information processing engineering, and tried to interpret multidimensional data by integrating. In this paper, we classified the ground property by SOM. The classification result is relatively conformal with boring data. Therefore, it is recognized that it can be used to improve the interpretative accuracy of compound geophysical explorations.12th ISRM International Congress on Rock Mechanics "Harmonizing Rock Mechanics and the Environment" 18-21 October 2011, Beijing, Chin

NOSS Altimeter Detailed Algorithm specifications

The details of the algorithms and data sets required for satellite radar altimeter data processing are documented in a form suitable for (1) development of the benchmark software and (2) coding the operational software. The algorithms reported in detail are those established for altimeter processing. The algorithms which required some additional development before documenting for production were only scoped. The algorithms are divided into two levels of processing. The first level converts the data to engineering units and applies corrections for instrument variations. The second level provides geophysical measurements derived from altimeter parameters for oceanographic users

Integrated geotechnical and geophysical investigation of a proposed construction site at Mowe, Southwestern Nigeria

The subsurface of a proposed site for building development in Mowe, Nigeria, using Standard Penetration Test (SPT), Cone Penetrometer Test (CPT) and Horizontal Electrical Profiling (HEP), was investigated with the aim of evaluating the suitability of the strata for foundation materials. Four SPT and CPT were conducted using 2.5 tonnes hammer. HEP utilizing Wenner array were performed with inter-electrode spacing of 10 – 60 m along four traverses coincident with each of the SPT and CPT. The HEP data were processed using DIPRO software and textural filtering of the resulting resistivity sections was implemented to enable delineation of hidden layers. Sandy lateritic clay, silty lateritic clay, clay, clayey sand and sand horizons were delineated. The SPT “N” value defined very soft to soft sandy lateritic (<4), stiff silty lateritic clay (7 – 12), very stiff silty clay (12 - 15), clayey sand (15- 20) and sand (27 – 37). Sandy lateritic clay (5-40 kg/cm2) and silty lateritic clay (25 - 65 kg/cm2) were defined from the CPT response. Sandy lateritic clay (220-750 Ωm), clay (< 50 Ωm) and sand (415-5359 Ωm) were delineated from the resistivity sections with two thin layers of silty lateritic clay and clayey sand defined in the texturally filtered resistivity sections. Incompetent clayey materials that are unsuitable for the foundation of the proposed structure underlain the study area to a depth of about 18m. Deep foundation involving piling through the incompetent shallow layers to the competent sand at 20 m depth was recommended

Geophysical characterization of derelict coalmine workings and mineshaft detection: a case study from Shrewsbury, United Kingdom

A study site of derelict coalmine workings near Shrewsbury, United Kingdom was the focus for multi‐phase, near‐surface geophysical investigations. Investigation objectives were: 1) site characterization for remaining relict infrastructure foundations, 2) locate an abandoned coalmine shaft, 3) determine if the shaft was open, filled or partially filled and 4) determine if the shaft was capped (and if possible characterize the capping material). Phase one included a desktop study and 3D microgravity modelling of the relict coalmine shaft thought to be on site. In phase two, electrical and electromagnetic surveys to determine site resistivity and conductivity were acquired together with fluxgate gradiometry and an initial microgravity survey. Phase three targeted the phase two geophysical anomalies and acquired high‐resolution self potential and ground penetrating radar datasets. The phased‐survey approach minimised site activity and survey costs. Geophysical results were compared and interpreted to characterize the site, the microgravity models were used to validate interpretations. Relict buildings, railway track remains with associated gravel and a partially filled coalmine shaft were located. Microgravity proved optimal to locate the mineshaft with radar profiles showing ‘side‐swipe’ effects from the mineshaft that did not directly underlie survey lines. Geophysical interpretations were then verified with subsequent geotechnical intrusive investigations. Comparisons of historical map records with intrusive geotechnical site investigations show care must be taken using map data alone, as the latter mineshaft locations was found to be inaccurate