With our lightweight seismic equipment
Off end shot
we are able to provide solutions on the most challenging environments where geotechnical surveys are not possible.
on field is essential for us to be able to offer the most efficient and suitable geophysical solutions.
Short explanation of the method
The method is built up on registering the seismical waves that refract from the geological layers that attributed with different velocities. A prerequisite of the application of the method is that the seismic velocities increases as the depth increases.
The seismic velocity in a vertical section normally increases towards the depth as the composition and consolidation of materials give higher velocities.
On land, we use geophones and 24 channel digital seismographs. The usual geophone distance is 5 meter in geophysical surveys that set up in a 115 meter profile. With our roll along method we are able to create multiple lines connected together by overlapping geophones. This technique enables us to cover huge areas in a time and budget effect way.
As greater sediment thickness requires longer profiles, 10 or even 20 meter geophone distance can be applicable . The shot points are usually five times of the geophone distances, that gives usually 5 in-line shots and 2 off-end shots in a 115 meter profile. This setup is required to create a bedrock curve that covers the whole length of the profile.
Quality ensurance model
The geophysical data interpretation is carried out in two waves in order in order to ensure quality and reliability in our results presented.
The manual interpretation is based on the ABC method that is fed by the observed geophysical and geological data. This method gives a layered model of the geophysical features of the Earth's sub-surface and present the layer boundaries and bedrock curve along the seismic profiles.
Parallel to the manual interpretation, we also carry out a software based interpretation of the geophysical data that is presented in an inversion model. The inversion model gives a good visualisation of the geological structures that is calculated by using the Shortest Path method based on Graph theory.
Concluding the interpretation process, we create a combined model by aligning and comparing the two methods against each other, therefore, ensuring quality and reliability in our results.
For our deliveries, we aim to provide clear and easily interpretable maps and geophysical sections.
Deres løsning innen anvendt geofysikk på land og sjø.
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