Volker Gundelach

Bundesanstalt für Geowissenschaften und Rohstoffe | BGR

The radioactive waste in the former Asse II salt mine has to be retrieved prior to the legally demanded decommissioning. In this context, the construction of a new mine and shaft is necessary, whereby detailed geological information about the salt structure is indispensable. Knowledge of the evaporite sequence, the internal composition, and the ext...

Examples of underground exploration by geophysics in clay, crystalline and salt for the search of a site to store high-level radioactive waste carried out by the Bundesanstalt für Geowissenschaften und Rohstoffe (BGR) in Hannover, Germany (Federal Institute for Geosciences and Natural Resources) https://dgg-online.de/WordPress_01/wp-content/upload...

The potash mine in the Asse salt structure, now used as repository for nuclear waste, is in some parts going to be refilled for mechanical stability reasons. As a part of that work, old blind shafts were prepared and offer the option for ground penetrating radar (GPR) measurements on vertical profiles in the mine. Horizontal profiles can be carried...

The radioactive waste in the former salt and potash mine Asse II needs to be retrieved for long-term safety reasons. For this purpose, a southeast expansion of the mine is necessary for which detailed geological information of the salt structure is essential. The site exploration was started and knowledge of the evaporite sequences and the interior...

The Allertal salt structure, used as repository for nuclear waste, was explored from the surface by seismic measurements and boreholes. Due to the accuracy of these investigations the position of the steep flank in the west of the salt structure is known. Underground, GPR (Ground penetrating radar) is an efficient and precise nondestructive tool fo...

In salt deposits with low electric conductivity ground penetrating radar (GPR) is an efficient non destructive tool for the exploration of internal structures. Faulted salt layers, potassium, clay, and anhydrite can be mapped by measuring distance and direction of reflecting objects. Various antenna types help to enhance resolution or penetration d...

Ground penetrating radar (GPR) – also designated as electromagnetic reflection technique (EMR) – is an efficient nondestructive tool for the exploration of underground salt deposits. Complex geological structures (bent, folded, sometimes faulted layering of salt, potassium, clay and anhydrite) in electrically low-conductive salt can be mapped by me...

Easy access to regionalise subsoil compaction on the field scale has not yet been realised with common soil physical methods. Caused by specific methodical limitation, reproducible results can commonly only be obtained in the laboratory. Existing field methods to access this problem allow simple punctual measurements, but are not adequate for a lar...

Airborne ground penetrating radar (GPR) measurements of geological structures and of temperate ice are a challenge because of absorption, internal scattering, and surface roughness. We found that at center frequencies of 30 MHz or below effects of scattering and roughness are sufficiently reduced to produce good quality radar data. We report result...

Geological structures and the water table were detected by GPR measurements in the sandy area of Letzlinger Heide (Germany). The glacial sediments consist of clayish lenses in sand and the water table is at a depth of more than 40 m. The strong lateral heterogeneity is known from boreholes. Different frequencies from 25 MHz to 200 MHz on the ground...

Due to the climate change it is a global task to fight against gas emission of coal fires. In China exists many burning coal seams which should be extinguished. A Chinese-German initiative tries to find new technologies and solutions to control these fires. Most of the fires are close to the surface in arid areas. In that case GPR is a possible geo...

The ground penetrating radar (GPR) method was used in a platinum mine in Zimbabwe by members of the Federal Institute for Geosciences and Mineral Resources (BGR). The measurements were carried out in boreholes and drifts. Electromagnetic reflections from a fault that consistently trends parallel to the mineralization zone permitted the mapping of t...

Spontaneous and industrially caused subsurface coal fires are worldwide disasters that destroy coal resources, cause air pollution and emit a large amount of green house gases. Especially in developing countries, such as China, India and Malaysia, this problem has intensified over the last 15 years. In China alone, 10 to 20 million tons of coal are...

Within the framework of the Sino-German research initiative "Innovative technologies for exploration, extinction and monitoring of coal fires in Northern China" a number of different geophysical methods have been applied to determine their use on coal fire detecting, accompanying the extinguishing processes, controlling of the extinction and finall...

To date an easy access to regionalise subsoil compaction on the field scale has not been realised with the common soil physical methods. Caused by their own methodical limitation, results can only be produced in the laboratory but with significance limited to the probed soil pit and therefore presenting only a local state of mechanical strength. Ex...

Aim of GPR measurements is not only to detect the spatial position of reflecting structures, but also to classify its geological reason. The reflection coefficient of a radar signal depends on the reflecting material. Numerous propeties of the recorded signal can be used to assign a reflection with geology. Necessary is the knowledge about unique p...

Underground, in mines it is important to get spatial information about the geology on limited profiles. In low conductive material, like salt, ground penetrating radar (GPR) is a valuable method to find structures in the environment. For radar measurements in boreholes a direction sensitive antenna can solve the problem of getting spatial informati...

GPR surveys provide important spatial data on the geological structures within salt deposits for the development of salt mines and the construction of caverns. GPR measurements can be carried out in shafts, drifts, and boreholes during exploration. Because these GPR measurements are carried out underground in full space, it is important to record a...

GPR borehole surveys provide important spatial data on the geological structures within mines. In this paper we want to show how the spatial relationships of complex geological structures are determined in a repository for radioactive waste in salt. Whether a discontinuity within a stratigraphic sequence can be detected depends on differences in th...