Application of the Differential interferometric technique (DInSAR) to unrevel the present-day vertical movement in the Glueckstadt Graben, Germany.
Bruno Crippa(1), Claudio Paleari(1), Anna Maria Marotta(1) and Ulf Bayer(2)
(1) University of Milan, Via Cicognara, 7, 20129, Italy
(2) Geoforschungszentrum Potsdam, Telegrafenberg, 14473, Germany
During the recent decades the availability of detailed geological, geophysical, geodetic and remote sensing data covering the crust in a basin environment calls for an integration at regional scale, in order to unravel the mechanisms of formation and evolution of the basins under changing stress. In particular, the broad range of geological and geophysical information can be combined with the results from a “quick-look” DInSAR analysis, quite useful to unrevel small vertical movements, such as those due to salts movements, and, thus, to better exploit the role that salt mobilization plays in a basin area. In this sense, the Glueckstadt Graben region is a good test site for this kind of analysis, since its tectonics has been strongly controlled by salts growth and movements in different times of its evolution. The Glueckstadt Graben is a major structure of the Central European Basin System. It locates along the transition zone between the Fennoscandian Shield and the NW Germany, where it overprints major structural units of the area and thus it plays a crucial role in the understanding of the dynamic of the area. The Glueckstadt Graben can be subdivided into three structural domains: 1) The Central Graben, of Triassic age; 2) the marginal Troughs – Westholstein, Eastholstein and Hamburger – of Jurassic age; 3) the Westschleswig and Eastholstein- Mecklenburg blocks, representing the flanks of the basin. The major phase of salt movements occurred during the Triassic, associated with extension and subsidence within the central part of the Trough. Two other phases of subsidence occurred during the Jurassic, when the area around the Glueckstadt Graben was relatively uplifted, and during the Cenozoic, when rapid subsidence occurred along the flanks of the basin. During the Late-Cretaceous-Tertiary, Africa-Eurasia convergence caused Alpine orogen and compression affected the whole of Europe. However, while many basins of the Central European Basin System underwent inversion, the Glueckstadt Graben was affected by rapid subsidence within the Westschleswig, Eastholstein and Hamburg Troughs. The DInSAR analysis has been done using ENVISAT images, centred at the Hamburger Trough and along the SE-NW direction. The methodology is based on the analysis of the interferogram stack, and the relative velocity is obtained by means of the differential phases adjustment. The analysis shows three major parallel areas, SW-NE directed, showing an alternating pattern of relative uplift, south-eastern of the Hamburger Trough, subsidence, in the centre of the Hamburger Trough, toward the Eastholstein Trough, and uplift, towards the Central Glueckstadt Graben, with respect to the Central Glueckstadt Graben or to the Luebeck areas. This pattern is in agreement with the trend highlighted by geological study.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,