Bedrock fracturing (KARIKKO project)
The aim of the project is to examine the characteristics and quality of bedrock fracturing in Southern Finland in different scales. Fracturing is investigated by large scale lineament interpretations based on geophysical and topographical data, orthophotos and 3D models produced by drone photogrammetry, and fracture maps based on these, as well as outcrop observations. In order to assess the possible post-glacial tectonic activity in the bedrock, brittle structures will also be compared with the glacial landforms. The project will utilise and develop methods of drone photogrammetry and it will include research and development of semi-automatic/automatic methods for analysing fracturing or lineament data, either with machine learning or algorithms.
By comparing observations made at different scales, the aim of the project is to evaluate the scalability and characteristics of bedrock fractures and the similarity of observations at different scales. If the fracturing can be verified to be similar in different scales, it is also possible to make predictions in different scales – this means, for example, that it would be possible to predict the nature of smaller-scale bedrock fractures based on lineament interpretations. The research also assesses the variation of fractures on a regional scale and seeks to assess the extent of the regions or volumes suitable for making predictions (Representative Elementary Volume, REV). REV is also covered in the sub-task ‘Evaluation of uncertainties’.
In addition to the comparison of data related to different scales, the project evaluates the use of geological data and interpretation, and stress modelling to predict fracturing characteristics. As a result of the project, a regional picture of the variations of bedrock fracturing at different scales will be created, which can be used to compare, for example, the brittle models and discrete fracture network models created for the Olkiluoto area with the broader regional geological characteristics. The scope of the project is broader than the objectives of the KYT2022 programme and its objectives meet the needs of society, e.g. in the modelling of flow of other harmful substances or in modelling of geothermal energy production.