Mapping karst "pockets" on the projected highway, Spain

In the spring of 2007, MSU-Geofizika LLC together with Spektr-Geofizika LLC and Moscow State University named after M.V. Lomonosov carried out geophysical studies in engineering surveys on the projected high-speed highway Madrid - Valencia.
The complex of geophysical methods of MTS, TEM, shallow FS was used. Frequency sounding was faced with the task of searching for karst zones (pockets) in the dolomites of the upper part of the section, which represent a serious danger to construction.
On the Aldesa section of the Madrid-Valencia highway, interpretation of the data allowed confirming the presence of a karst zone (increased conductivity area) on PC 904900-905100, as well as delineating the karst pocket on PC 905250-905300, estimating the depth and shape of karst zones (pockets).