Geophysics in Densely Populated Urban Areas – Two Cases from Finland

Airborne and ground geophysical data have been tested and utilized in several projects in urban geological studies in the Finnish geological environment. Geophysical data has been used together with geological data in structural studies of bedrock and soil. Two cases are presented in this paper. The first case is a regional scale KallioINFO project where the aim was to develop a geological information system, so called GeoTIETO-portal, for land use planning, environmental planning and construction purposes. The second case is a local scale project that focuses on the studies at new construction area, Suurpelto locality, in the City of Espoo. In both of the project airborne and geophysical data was used widely. The KallioINFO project concentrated on the bedrock and soil structure studies around the Helsinki Capital region. In the Suurpelto project the main idea was to investigate the geological history and soil structure at the study site before breaking ground. Results in both projects were promising. The airborne magnetic data was the most valuable tool in the mapping of bedrock in urban areas. Airborne EM, gravity and ERT measurements proved to be very useful adds in outlining and characterizing the soft-soil areas for the construction purposes.