Complex Surface Displacements above the Storage Cavern Field at Epe, NW-Germany, Observed by Multi-Temporal SAR-Interferometry

Abstract

The storage cavern field at Epe has been brined out of a salt deposit belonging to the lower Rhine salt flat, which extends under the surface of the North German lowlands and part of the Netherlands. Cavern convergence and operational pressure changes cause surface displacements that have been studied for this work with the help of SAR interferometry (InSAR) using distributed and persistent scatterers. Vertical and East-West movements have been determined based on Sentinel-1 data from ascending and descending orbit. Simple geophysical modeling is used to support InSAR processing and helps to interpret the observations. In particular, an approach is presented that allows to relate the deposit pressures with the observed surface displacements. Seasonal movements occurring over a fen situated over the western part of the storage site further complicate the analysis. Findings are validated with ground truth from levelling and groundwater level measurements.

Quantitative Assessment of Vertical and Horizontal Deformations Derived by 3D and 2D Decompositions of InSAR Line-of-Sight Measurements to Supplement Industry Surveillance Programs in the Tengiz Oilfield (Kazakhstan)

“…Our research focused on the quantitative assessment of the surface deformation velocities and rates and their natural and man-made controlling factors at the Tengiz oilfield using Small Baseline Subset (SBAS) remote sensing and geostatistical interpolation techniques followed by 3D and 2D decompositions and cosine corrections to derive vertical and horizontal movements from LOS measurements. According to Even et al [20], 2D and 3D displacements in vertical, east-west and north-south directions derived from InSAR LOS measurements holds a fundamental role for the integrated analysis and integration with other data of oil and gas reservoirs. A number of successful InSAR studies applied 3D and 2D decompositions and cosine corrections techniques to derive vertical and horizontal deformations for oil and gas fields [1,21,22].…”

Monitoring of Land Subsidence in the Po River Delta (Northern Italy) Using Geodetic Networks

“…Land subsidence afflicts many areas of the world, in particular the ones located along transitional environments, such as coastal areas, deltas, wetlands, and lagoons, which are becoming increasingly vulnerable to flooding, storm surges, salinization, and permanent inundation [6][7][8][9]. In these areas, subsidence can be usually considered as a consequence of a complex combination of natural and anthropogenic factors: the compaction of Holocene sediments, tectonic movements, sinkholes formation, volcanism, thawing permafrost, and the Glacial Isostatic Adjustment (GIA), are generally considered as the main natural sources of land subsidence [10][11][12]; aquifer-system compaction associated with groundwater/oil/natural gas depletion and storage, drainage of organic soils, underground mining, hydro-compaction and stress given by new constructions, are the principal drivers of the anthropogenic land subsidence [13][14][15][16][17][18][19]. Moreover, the effects of climate change can dramatically increase the subsidence-related problems due to the rising of sea levels: the 2012 Intergovernmental Panel on Climate Change (IPCC, www.ipcc.ch, (accessed on 9 April 2021)) report, in fact, highlight an increasing occurrence of coastal and fluvial flooding, extreme weather events and sea-level rise as a consequence of climate change during the XXI century.…”

Editorial for Special Issue “Monitoring Land Subsidence Using Remote Sensing”

“…Even et al [18] applied InSAR using both PS and SBAS approaches to study the complex displacement field caused by convergence and operational pressure changes of the natural gas storage field at Epe (N-W Germany). The authors processed 86 and 118 SAR images, respectively, in ascending and descending orbits; they compared the InSAR results with leveling data acquired during three surveys between 2015 and 2017 (517 points in total) and ground water measurements at 97 locations.…”

“…The PSI and SBAS approaches can be successfully applied over many different ground targets such as buildings, infrastructures, outcrops, base soils, low-vegetated area, etc. [11], and in several research fields, such as tectonics and volcanology [15], landslides [10,11,16], clay deposits deformations [5,17], and groundwater/oil/natural gas depletion [9,18].…”

“…The possibility to combine the results obtained from the analysis of SAR images acquired in both ascending and descending geometries allows the computation of the vertical and east-west components of movement, which is fundamental for data interpretation and for the integration with other techniques [18].…”