Induced Seismic Events—Distribution of Ground Surface Displacements Based on InSAR Methods and Mogi and Yang Models

Abstract

In this article, we present a possible approach to use satellite radar data for a complete description of the formation process of a subsidence trough resulting from an induced seismic event—a mining tremor. Our main goal was to verify whether SAR data allow for the calculation of the basic indicators for the trough (w—subsidence, T—trough slope, K—curvature, u—horizontal displacements, ε—horizontal deformations). We verified the extent to which the Mogi and Yang models can be fitted to match the actual displacements recorded after an induced seismic tremor. The calculations were performed for the Legnica-Glogow Copper Belt (LGCB) area in southwest Poland. Due to intensive mining operations and specific geological and tectonic conditions, the area shows a high level of induced seismic activity. Our detailed analysis focused on four powerful mining tremors: the first tremor occurred on 29 November 2016 (MW3.4), the second on 7 December 2017 (MW3.3), the next on 26 December 2017 (MW3.6) and the last tremor on 29 January 2019 (MW3.7). For each analyzed event, we determined the displacements based on the Differential Interferometric Synthetic Aperture Radar (DInSAR) method and Sentinel 1 synthetic aperture radar (SAR) data from two paths (22 and 73). Additionally, for the period from November 2014 to October 2020, we calculated the displacements using the Small Baseline Subset method (SBAS) time series method. In all cases, the tremor was followed by the development of long-lasting surface deformations. The obtained results allowed us to conclude that it is possible to calculate indicators that result from a specific induced mining event. Considering the full moment tensor and nature of the tremor source, we demonstrated that the Mogi and Yang models can be employed to describe the influence of an induced tremor on the surface in an area of mining activity. We also confirmed the global character of the influence of the reduced troposphere on SAR data calculations. Our conclusions indicate that accounting for the tropospheric correction does not distort horizontal and vertical displacement values in regions influenced by mining activity/tremors.

Land Subsidence Estimation for Aquifer Drainage Induced by Underground Mining

“…Land subsidence due to mining is mainly caused by removing a deposit from a rock mass and forming a post-mining void [46]. This type of land subsidence can damage the surface and underground infrastructure and endanger surface users' safety [8,[47][48][49][50][51]. Land subsidence's spatial extent and value are primarily determined by the depth of exploitation, seam thickness, panel dimensions, overlying rock mass geomechanical conditions, geological defects, surface topography, production methods and post-mining void reclamation method [30,52,53].…”

“…Land subsidence's spatial extent and value are primarily determined by the depth of exploitation, seam thickness, panel dimensions, overlying rock mass geomechanical conditions, geological defects, surface topography, production methods and post-mining void reclamation method [30,52,53]. Many research papers have been presented in recent years documenting the land subsidence phenomenon caused by mining [47,49,[54][55][56][57][58][59][60][61][62][63]. As a result, one can be stated that the spatial extent of the phenomenon can range from several km 2 [49] to tens of km 2 [15], while its values can range from a few mm/year [64] to several cm/day [65].…”

“…There has also been a significant amount of research carried out on using LIDAR, InSAR and UAV techniques in monitoring land subsidence in mining areas [50,[85][86][87][88][89][90][91][92]. However, these are primarily focused on analyzing temporal changes land subsidence [93] and horizontal ground movements [94][95][96], investigating sinkholes near former mine workings and shafts [97], studying mining-induced tremors [8,47,[98][99][100][101][102][103] and updating elevation maps for administrative purposes [51,102].…”

Estimation of Mining-Induced Horizontal Strain Tensor of Land Surface Applying InSAR

“…Every year, at least a few earthquakes with energies greater than 10E7 J are recorded [61,[67][68][69][70][71]. Moreover, mining-induced earthquakes in the study area caused much greater velocity and quantity of ground displacements than land subsidence caused directly by the extraction of copper ore deposits [67,[72][73][74][75][76][77][78][79][80][81][82][83].…”

Prediction of Ground Surface Deformation Induced by Earthquake on Urban Area Using Machine Learning

“…The two models were compared with inversion techniques of an elastic half-space dislocation model and long-term data from a global positioning system (GPS) on surface deformation data (Mattioli et al, 2010) . The Mogi and Yang models were used to match actual displacements recorded after a seismic earthquake using satellite radar data based on fundamental indicators of subsidence, slope, curvature, horizontal displacements, and horizontal deformations (Milczarek et al, 2021;Meng et al, 2022).…”