Mapping Bedrock Layering, Fault Zones and Saline Groundwater by Airborne TEM on the Island of Gotland, Sweden
L. Persson, M. Bastani, M. Erlström, C.A. Triumf, P. Dahlqvist and F. Jørgensen
Event name: First European Airborne Electromagnetics Conference
Session: Geological and Hydrological Applications
Publication date: 06 September 2015
Info: Extended abstract, PDF ( 1.21Mb )
Price: € 20
An airborne transient electromagnetic survey (ATEM) was carried out over four areas on the island of Gotland, Sweden, for groundwater planning purposes. The primary aim of the study was to locate areas with large groundwater capacity and to identify the depth to saline groundwater. The result from the ATEM survey indicates several sites and areas, which have been assessed as favourable for groundwater extraction. The data also reveal new and previously unknown information regarding the layering and structure of the subsurface geology down to approximately 200 m depth. An example from one of the surveyed areas shows that both the thickness of the upper limestone unit as well as the interface to the underlying marlstone and depth to saline groundwater is effectively mapped by the ATEM survey. In the second example a fault zone is clearly visualized, possibly also associated with increased groundwater circulation in a zone with fractured rock.