| Title | Airborne time-domain electromagnetics for three-dimensional mapping and characterization of the Spiritwood Valley Aquifer |
| Author | Oldenborger, G A; Pugin, A J M; Pullan, S E |
| Source | Symposium on the Application of Geophysics to Environmental and Engineering Problems, abstracts volume; by Environmental & Engineering Geophysical Society; 2012. |
| Year | 2012 |
| Alt Series | Earth Sciences Sector, Contribution Series 20110309 |
| Meeting | Symposium on the Application of Geophysics to Environmental and Engineering Problems; Tucson, AZ; US; March 25-29, 2012 |
| Document | book |
| Lang. | English |
| Media | paper |
| Province | Manitoba |
| NTS | 62G/03; 62G/04; 62G/05; 62G/06 |
| Area | Spiritwood Valley; Killarney; Cartwright; Pelican Lake |
| Lat/Long WENS | -99.7667 -99.1333 49.4258 49.0000 |
| Subjects | geophysics; hydrogeology; geophysical surveys; e m surveys; e m surveys, airborne; conductivity surveys; electrical surveys; seismic reflection surveys; seismic interpretations; geophysical
interpretations; aquifers; seismic profiles |
| Illustrations | location maps |
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| Program | Aquifer Assessment & support to mapping, Groundwater Geoscience |
| Abstract | The Geological Survey of Canada commissioned a helicopter-borne time-domain electromagnetic (HTEM) survey over a 1062 km2 area of the Spiritwood Valley in southern Manitoba in order to test the
effectiveness of airborne time-domain electromagnetics for mapping and characterizing buried valley aquifers in the Canadian Prairies. The HTEM data exhibit rich information content; apparent conductivity maps clearly image the Spiritwood Valley in
addition to a continuous incised valley along the broader valley bottom. We detect complex valley morphology with nested scales of valleys including at least three distinct valley features and multiple possible tributaries. Conductivity-depth images
(CDI) derived from the TEM decays indicate that the fill materials within the incised valleys are more resistive than the broader valley fill, consistent with an interpretation of sand and gravel. Comparison of ground-based electrical resistivity and
seismic reflection data allow for calibration of CDI models. Lateral spatial information is in excellent agreement between data sets. The seismic data reveal the presence of additional valley features that are not imaged by the HTEM data as having a
distinct electrical signature, possibly due to diamicton fill. The CDI model underestimates the dynamic range of electrical conductivity while overestimating depths to valley bottoms; these issues are associated with finite system bandwidth,
algorithm limitations and penetration depth. The integrated data sets illustrate that HTEM surveys have the potential to map complicated buried valley aquifers at a level of detail required for groundwater prospecting and management. |
| GEOSCAN ID | 289679 |
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