Geophysics ~ Working Group
Sigwartstrasse 10 ~ D-72076 Tübingen
Search | Sitemap | Impressum | Login


Projects: GPR techniques and Geotomography


Note:

Presently, there are no active projects in this field! (June 2011)

 

GPR techniques and Geotomographyaulic properties

High resolution geotomography and 3-D GPR techniques to characterize Quarternary gravel deposits and their hydraulic properties

Quarternary sand and gravel deposits characterise one of the most important aquifer type in South Germany and in many other parts of the world. To understand and model groundwater flow and contaminant transport in these high heterogenous systems a detailed image of the subsurface is needed. Techniques must be developed which lead to high resolution characterisation of sedimentological structures and their hydraulic properties in the regions of interest. Geophysical methods and especially their combination with hydrogeological data and sedimentological knowledge seem to be a promising tool for a better understanding of such deposits and their hydraulic response.

 

Applied geophysical methods mainly include surface GPR measurements and tomographical imaging. On the picture below you can see our GPR equipment during profiling in the Neckar valley. GPR, which is a time domain electromagnetical technique similar to reflection seismics, provides high resolution structural information of the shallow subsurface. Therefore, it is an ideal tool for the 3-D visualization of different sedimentological units in unconsolidated deposits.

Geotomography is similar to the tomographical imaging techniques known from medicine. It represents a possibility to obtain and correlate physical properties of the geological medium - e.g. seismic or EM velocity distribution - between boreholes. The calculated tomogramms can be interpreted in view of sedimentological units and hydraulic properties. On the picture below, you can see our Borehole Radar System with 100 MHz antennas during field work.

GPR profiling
Crosshole radar surveying

Sharing the potential of different techniques, such as radar tomography and GPR reflection surveying, helps to constrain the final interpretation of geophysical data. Outcrop validation experiments (see image and animation below) allow to evaluate the possibilities of each geophysical tool and of intergrated surveying.

Validation of geophysical techniques by outcrop comparison. - Click to view animated

This project stands in close cooperation with the groups of Sedimentary Geology and Hydrogeology.