Extracting Structural Data from Satellite Data in Arctic and Remote Environments
Robert M. Stesky1 and Paul Budkewitsch2
1Pangaea Scientific, Brockville, ON, Canada.
2Natural Resources Canada, Ottawa, ON, Canada.
Structural mapping of the large-scale internal geometry of geological bodies is often a challenging task. Various physical, environmental and financial factors can limit the ability to acquire the necessary information. Poor outcrop exposures, difficulties making magnetic compass measurements and remote or inaccessible locations are among them. Yet, having some prior knowledge of this large-scale geometry can help in the planning of field work, seismic surveys and other decisions to support the efficient allocation of resources.
One available, yet little used, option are images from various satellite sources when used with digital elevation data. The principle is based on the classic “three-point problem,” long used to teach geology students how to read structural maps. One can calculate the orientation of a structural plane from the spatial coordinates of at least three points on that planar surface. By measuring such sets of points at various locations within the image, the geologist can construct a structural orientation map of the observed strata and use that map to estimate the internal geometry of the lithological units in the area. This map is incomplete, of course, since only planar measurements can be made, and it requires that lithological contacts be visible in the image. Nevertheless, a large number of quantitative estimates of structural attitudes can be made and much learned while still in the office to constrain the ideas about the region’s geology and to help guide field investigation.
We describe a fully functional and robust methodology in more detail and give examples from three areas in the Canadian Arctic. Images are available at various spatial resolutions allowing us to explore the effect of image resolution on the measurements. Because the regions have a range of reliefs, from low to moderate, these examples help to define the limits to the method, validated by ground measurements with which to compare the results.
AAPG Search and Discovery Article #90130©2011 3P Arctic, The Polar Petroleum Potential Conference & Exhibition, Halifax, Nova Scotia, Canada, 30 August-2 September, 2011.������������������������������������������������������