Posts Tagged Groundwater

Recent investigations of geophysics abilities in aquifer mapping and resource evaluation

Posted by on Thursday, 13 March, 2014

Buried beneath the glaciated terrain, valleys filled with coarse-grained permeable sediments  potentially are great sources of fresh ground water. During the last several years Geological Survey of Canada has been investigating geophysical methods potential, particularly airborne electromagntics, for mapping and resource evaluation of buried valleys.   Spiritwood valley aquifer in southern Manitoba has been chosen for the investigations. Heliborne AeroTEM, VTEM, fixed-wing TEMPEST and MULTIPULSE, ground electrical resistivity and time-domain methods, seismic reflection and borehole data have been involved into the complex analysis. Recently collected ground TEM data for Spiritwood and the report (G.A. Oldenborger and K. Brewer, 2014) has been released: http://geoscan.nrcan.gc.ca/starweb/geoscan/servlet.starweb?path=geoscan/fulle.web&search1=R=293700.

One of the successful heliborne TEM examples (Legault, J.M., Prikhodko, A., Dodds, D.J., MacNae, J.C., Oldenborger, G.A., 2012. Results of recent VTEM helicopter system development testing over the Spiritwood Valley aquifer, Manitoba. Symposium on the Application of Geophysics to Environmental and Engineering Problems. Environmental and Engineering Geophysical Society, 114–130.):

VTEM-ground

 

 

 

 

 

 

 

 

 

 

 

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Another recent example of the results of a combined seismic and airborne electromagnetic (AEM) interpretation of the shallow Quaternary sedimentsand  bedrock but in British Columbia (Horn River Basin) was presented on Geoconvetion-2013  .

 

 


Analysis of Electromagnetic and Seismic Geophysical Methods for Hydrogeology

Posted by on Sunday, 11 April, 2010

Eric M. Parks “Analysis of Electromagnetic and Seismic Geophysical Methods for Investigating Shallow Sub-surface Hydrogeology”. The thesis submitted to the faculty of Brigham Young University (Utah) in partial fulfillment of the requirements for the degree of Masters of Science.

“An integrated electromagnetic (EM) and seismic geophysical study was performed to evaluate non-invasive approaches to estimate depth to shallow groundwater in arid environments with elevated soil salinity where the installation of piezometers would be impractical or prohibited. Both methods were tested in two study areas (semi-arid and arid respectively), one in Palmyra, Utah, USA near the shore of Utah Lake where groundwater is shallow and unconfined in relatively homogeneous lacustrine sediments. The other area is Carson Slough, Nevada, USA near Ash Meadows National Wildlife Refuge in Amargosa Valley. The area is underlain by valley fill, with generally variable shallow depths to water in an ephemeral braided stream environment. The methods used include frequency domain electromagnetic induction allowing for multiple antenna-receiver spacings. High resolution compressional P-wave seismic profiles using a short (0.305 m) geophone spacing for common depth-point reflection stacking and first arrival modeling were also acquired. Both methods were deployed over several profiles where shallow piezometer control was present.”  ..more information.


Magnetic Resonance Sounding for groundwater

Posted by on Thursday, 24 December, 2009

Anatoly Legchenko (LTHE, IRD, France) and Ugur Yaramanci (LIAG, Germany) report on the 4th International Workshop on the magnetic resonance sounding (MRS) method applied to non-invasive groundwater investigations, held in October at the University Joseph Fourier, Grenoble, France.

Magnetic resonance sounding (MRS) is a recently developed method for hydrogeophysical exploration. The very first soundings were carried out between 1979 and 1981. Since 1996, when a new generation of MRS equipment became commercially available, the number of MRS users has been increasing. Arrival of this geophysical method initiated intensive scientific discussions and exchange of experience. Apart from traditional geophysical meetings, these exchanges were channelled through specialized workshops: Berlin, 1999; Orléans, 2003; and Madrid, 2006.

While the efficiency of the MRS applied to groundwater-related studies is already proven, many technical details are still under development. A new generation of hardware and continuing progress with software are expected to improve accuracy and robustness of the technique. Thus, MRS workshops continue contributing to development of the method and establishing new scientific collaborations.

The 4th International Workshop was organized by the Laboratoire d’étude des Transferts en Hydrologie et Environnement (LTHE), Grenoble, France in co-operation with the Leibniz Institute for Applied Geophysics (LIAG), Hannover, Germany. The organizer got scientific support from different research organizations and national geological surveys; Near Surface Geoscience Division (NSGD) of European Association of Geoscientists & Engineers (EAGE); Institut de Recherche pour le Développement (IRD), France; Berlin University of Technology (TUB), Germany; Université Joseph Fourier (UJF), France; Federal Institute for Geosciences and Natural Resources (BGR), Germany; Bureau de Recherches Géologiques et Minières (BRGM), France; and Instituto Geologico y Minero de España (IGME), Spain.

Organization of this event was made possible thanks to financial support of BRGM, IRIS-Instruments, and LTHE, and the administraton of Grenoble city. The MRS2009 workshop was attended by 81 participants from 19 countries. In total, there were 46 contributions to the workshop given by scientists from different countries.

Communications and discussions during MRS2009 Workshop took place in a friendly and constructive atmosphere and covered a large spectrum of subjects related to instrumentation, data processing, modelling, inversion, and field results. The technical programme consisted of different topics addressing all aspects of MRS.

It has already become a tradition to publish the most significant contributions on MRS in special issues of European geophysical journals. For MRS2009 it was decided that a special issue of Near Surface Geophysics will be prepared. This will also be open to authors who did not attend the workshop but want to submit original article related to MRS method. The deadline for submission is set to 31 December, 2009.

Looking ahead, the 5th International Workshop on MRS will be organized in Hannover in fall 2012.

Some details from IRIS Instruments: http://www.iris-instruments.com/Pdf%20file/7-Magnetic_Resonance/presentation_%26_papers.pdf


SkyTEM’s groundwater case study in Italy

Posted by on Saturday, 19 December, 2009

Aarhus Geophysics ApS at Department of Earth Sciences of University of Aarhus (Denmark) which provides software and know-how for large scale surveys, presents some news about their activity.

At software level, the Aarhus Workbench has undergone a robust developing phase on the GIS components, and on the QC of inversion results: completely revolutionized the colour scale interface, created a shading option for horizontal maps, and the possibility to create comprehensive print ready pdf maps is activated. Regarding the second issue, the user can now visualize, with just few clicks, different maps on the GIS component of the parameters that allow to QC inversion results. These include, for example, data residual, difference between frame altitude input and output, model parameter sensitivity analysis, etc.

In terms of AEM data processing, inversion and survey planning it is also continuing with a number of new projects both for private and public clients worldwide. As an example,  the first ever AEM survey dataset from the Venice lagoon, in Italy has processed. The results of this project are very promising in terms of applicability of AEM data to hydrogeological modeling within and underneath wetlands, lagoons, and surface waters in general. The description of the project: “Surface water–groundwater exchange in transitional coastal environments by airborne electromagnetics : The Venice Lagoon example” (pdf). The low 12.5 Hz base frequency was used on the project.


Applied Geophysics – some of the books published in 2009

Posted by on Saturday, 28 November, 2009

Exploration Geophysics, Gadallah, Mamdouh R., Fisher, Ray.

Many text books have been written on the subject “Exploration Geophysics”. The majority of these texts focus on the theory and the mathematical treatment of the subject matter but lack treatment of practical aspects of geophysical exploration. This text is written in simple English to explain the physical meaning of jargon, or terms used in the industry. It describes how seismic data is acquired in 2-D and 3-D, how they are processed to convert the raw data to seismic vertical and horizontal cross sections, that are geologically meaningful, and how these and other data are interpreted to delineate a prospect. Workshops are included after each chapter and are designed to reinforce learning of the concepts presented.

Groundwater Geophysics. A Tool for HydrogeologyKirsch, Reinhard (Ed.).

Geophysical techniques can map the underground conditions apart from boreholes. The use of these methods for hydrogeological applications is demonstrated for mapping of porous aquifers, mapping of structural aquifers, determintation of groundwater quality (mineralization), geophysical assessment of hydraulic properties, determination of aquifer vulnerability, and mapping of comtaminated sites. Additionally, a description of applied geophysical techniques used for groundwater studies is given including seismics, resistivity methods, magnetics, and ground penetrating radar. Even advanced techniques like NMR (nuclear magnetic resonance) are presented.

Principles of the Magnetic Methods in Geophysics Volume 42. By Alex A. Kaufman, Richard O. Hansen and Robert L. Kleinberg

Covers all the physical and mathematical principles of magnetic methods regardless of the area of application and  presents thorough developments of magnetic methods.


Geophysical Electromagnetic Theory and Methods Volume 43. Michael S. Zhdanov

In this book the author presents the state-of-the-art electromagnetic (EM) theories and methods employed in EM geophysical exploration.
The book brings together the fundamental theory of EM fields and the practical aspects of EM exploration for mineral and energy resources.
This text is unique in its breadth and completeness in providing an overview of EM geophysical exploration technology.