Monitoring post-mining subsidence in the Nord-Pas-de-Calais coal basin (France): comparison between interferometric SAR results and levelling |
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| Authors: | D Raucoules S Le Mouelic C Carnec Y Guise |
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| Institution: | 1. BRGM ARN, 117 avenue de Luminy, 13276 Marseille cedex 9 , France d.raucoules@brgm.fr;3. Université de Nantes Laboratoire de Planetologie et Geodynamique , 2 rue de la Houssiniere, 44322 Nantes cedex 3, France;4. BRGM ARN, 117 avenue de Luminy, 13276 Marseille cedex 9 , France;5. Charbonnages de France , Avenue de la Fosse 2, 62420 Billy Montigny, France |
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| Abstract: | The interferometric synthetic aperture radar (InSAR) technique is used to detect surface deformations in the French Nord-Pas-de-Calais coal mining basin. Several subsiding areas had already been observed at the sites of Lens, Billy-Montigny, Courrières and Ostricourt during the 1992–2000 period. InSAR deformation measurements are compared with ground-based levelling measurements and an analysis of the results shows a good agreement for the relative deformations. However, the InSAR study reveals a systematic bias of the absolute levelling values. Our interpretation is that the stability points of the ground-based monitoring network probably moved during the study period. Such cross-checking is particularly important considering the current legal value of the levelling measurements. |
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| Keywords: | post-mining subsidence InSAR |
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