| Title | Modeling of fast ground subsidence observed in southern Saskatchewan (Canada) during 2008-2011
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| Author | Samsonov, S V ;
González, P J; Tiampo, K F; d'Oreye, N |
| Source | Natural Hazards and Earth System Sciences vol. 14, 2013 p. 247-257, https://doi.org/10.5194/nhess-14-247-2014  Open Access |
| Links | Supplementary material online
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| Image |  |
| Year | 2013 |
| Alt Series | Earth Sciences Sector, Contribution Series 20130204 |
| Publisher | Copernicus GmbH |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf; html |
| Province | Saskatchewan |
| NTS | 73B/02; 73B/03 |
| Area | Saskatoon; Rice Lake |
| Lat/Long WENS | -107.5000 -106.5000 52.2500 52.0000 |
| Subjects | geophysics; subsidence; analytical methods; modelling |
| Program | Remote Sensing Science |
| Released | 2014 02 14 |
| Abstract | Fast ground subsidence in southern Saskatchewan (Canada) between the City of Saskatoon and Rice Lake was observed with the RADARSAT-2 Interferometric Synthetic Aperture Radar (InSAR) during 2008-2011.
We collected 23 ascending Multi- Look Fine 3 Far (MF3F) and 15 descending Standard 3 (S3) RADARSAT-2 images and performed time series analysis utilizing SBAS and MSBAS methodologies. We observed two well-defined circular regions located a few km
apart and subsiding with the nearly constant rate of about 10 cm yr?1. MSBAS decomposition revealed presence of both vertical and horizontal ground displacements. For further analysis we se lected two highly coherent interferograms spanning from
November-December 2009 until April 2010 that due to particularly favorable ground conditions displayed superior coherence. We performed modeling and inversion assuming spherical and sill source
models in order to determine the source location,
depth and strength. The smallest residual of about 1 cm yr-1 was achieved with the sill model when both, ascending and descending, interferograms were used. This model suggested sources located at 1.3 and 1.2 km depth with radius of 1.0 and 1.3 km
for eastern and western areas, respectively. The spherical model suggested slightly shallower sources located at 0.9 and 0.8 km. We could not precisely identify the cause of this deformation but the observed subsidence rate and source depth suggest
mining related origin. Topographic changes produced by this subsidence rate over a long time may produce shallow groundwater redistribution and flooding of agricultural lands. |
| Summary | (Plain Language Summary, not published)
A high rate of ground subsidence in southern Saskatchewan (Canada) between Saskatoon and Rice Lake was observed using RADARSAT-2 Interferometric
Synthetic Aperture Radar (InSAR) during 2008-2011. We observed two well-defined circular regions, located a few km apart, which are subsiding at a nearly constant rate of about 10 cm/year. Two geophysical models were used in an attempt to locate and
characterise factors causing the subsidence. The best model (sill model) suggested the source of the subsidence was located at depths of 1.3 and 1.2 km with a radius of 1.0 and 1.3 km. The spherical model suggested slightly shallower sources located
at depths of 0.9 and 0.8 km. The cause of the deformation could not be precisely identified. However, the observed subsidence rate and source depth suggests a link to mining-related extraction activities. Topographic changes produced by this
subsidence over an extended period may result in a redistribution of shallow groundwater and potentially flooding of agricultural lands. |
| GEOSCAN ID | 293015 |
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