Last weekend parts of the MIRACHL team performed a new field campaign at the Alingsås site. This time, we used another method from our large geophysical toolbox, a seismic landstreamer, in order to further investigate the area and determine the depth to the bedrock. This will help us to better understand the migration of the plume of contaminants and also constrain the measurements from the DCIP monitoring system. The seismic campaign was designed for refraction analysis.
In the seismic refraction method, we are generating a seismic wave, by an accelerated weight drop which is mounted on the rear of the car (see photo). As the wave propagates into the ground, we record the time that it takes to reach our sensors (see photo) along the line, which makes it possible to determine the subsurface structure.
It is crucial to minimize the interference from the environment and for that reason it is not very uncommon to perform seismic measurements even during the night. We chose to acquire the data over the weekend, so the operation of the laundry facility unit will not ”contaminate” our recordings.
We are looking forward to processing the data and enhance our knowledge and understanding about the area.