Environmental and Engineering Geophysics

Description

The focus in ENGE480 is on near-surface geophysics and its applications, which include mapping and monitoring of groundwater resources, engineering applications, mapping of structure and stratigraphy, and archæological and forensic work. The material covered in ENGE480 should provide much of the background needed to begin to read, and ultimately contribute to, the geophysical technical literature. Near-surface geophysics complements ENGE478 (Applied Hydrogeology), GEOL473 (Structural Geology) and GEOL477 (Sediment Transportation and Deposition), and is intended to give students an advanced introduction to geophysical surveying for environmental and engineering applications. ENGE480 will be taught in the first semester, and a background equivalent to GEOL337 or ENCI472 is expected, although exceptions will be made with the permission of the instructor.

Course Content
The topic list is tentative. A lecture format is used to start, but a seminar discussion style is used later. A field project forms the core of the assessment.

Introduction: Course goals and structure; physical properties and geophysical responses; advantages and limitations of geophysical surveying; survey design.

Data Acquisition and Signal Processing: Basic principles of signal processing; sampling and aliasing; domains; transforms; filters; convolution and deconvolution; modelling and inversion.

Potential Field Methods: Advanced concepts in gravity and magnetic surveys; gradiometry; modelling; non-uniqueness - “equivalent stratum”; Euler deconvolution applications.

Electrical Methods: Advanced concepts - survey modes equivalence; tomography; induced polarisation; applications.

Electromagnetic Methods: Advanced concepts; frequency vs time-domain; equivalence; comparison of sensitivity between resistivity and EM; applications.

Seismic Refraction: Principles of refraction and reflection; survey modes; applications; relative merits of refraction vs reflection; applications.

Seismic and Radar Reflection: Seismic vs radar - similarities and differences; survey modes; processing; applications.

Borehole Logging: Advanced principles; processing and interpretation, including principal component analysis.

Case Histories: Examples for discussion, particularly from recent literature on applications of near-surface geophysical methods to engineering applications, shallow stratigraphic mapping, neotectonics, mapping and monitoring of groundwater resources and groundwater contamination, archæology, glaciology, and forensic studies. Examples will be geared to the interests of the students.