Geophysical field experiment
Active-source seismology on a riverbank in Yunnan
A controlled seismic source allows structures that cannot be seen at the surface to be inferred from the waves that return to an array of instruments.
- Method
- Active-source seismology
- Setting
- Riverbank in Yunnan
- Target
- Subsurface impedance interfaces
From a surface impact to a subsurface image
We generate seismic waves at the ground surface and record their travel through the subsurface. When a wave encounters a boundary between rocks with different density or seismic velocity, part of its energy is reflected or refracted and returns to the surface.
The arrival times and amplitudes of these signals are used to invert the geometry and physical contrasts of underground layers. This photograph was taken while I was generating an artificial source beside a river in Yunnan and recording data to locate subsurface impedance boundaries, with the aim of identifying possible groundwater-bearing structures.