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| Titel |
Mapping and modelling of collapse sinkholes in soluble rock: the Münsterdorf site, northern Germany |
| VerfasserIn |
Georg Kaufmann, Douchko Romanov |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250142487
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| Publikation (Nr.) |
 EGU/EGU2017-6116.pdf |
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| Zusammenfassung |
| Münsterdorf is a small village in the north of Hamburg, located along the northern rim of a
salt diapir. The Permian rocks are uplifted and overlying rocks such as the cretaceous
limestone, normally in several kilometres depth, have been pushed up close to the surface. In
Münsterdorf, the cretaceous limestone can be found in around 20 m depth, and
about 2 km further south, cretaceous limestones are quarried in a large open-pit
mine.
Since 2004, collapse sinkholes form on a sporting ground in Münsterdorf, with a
frequency of about 1 per year, about 2-3 m in diameter and 3-5 m deep. The collapse
sinkholes do not reach the underlying limestone, but seem to be related to accelerated
dissolution in that formation. Above the cretacious limestone, quaternary gravels and glacial
marls provide a non-soluble, but permeable and heterogeneous cover of about 20 m
thickness.
We have mapped the sporting ground and its vicinity with gravity (GRAV), electrical
resistivity imaging (ERI), self-potential measurements (SP), and ground-penetrating radar
(GPR). While GRAV and SP is fairly unspectacular, the ERI profiles indicate a significant
change in the surface layer, from thin and irregular in the northern part to thicker and more
homogeneous in the southern part of the sporting ground. GPR profiles confirm this
result.
With numerically modelling the evolution of flow and porosity in the cretaceous
limestone, we discuss the potential cause of the sinkhole formation and its sudden onset. |
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