3D modelling is a sophisticated computer-based tool that enables the three-dimensional representation of any object or surface. It has become increasingly popular also in geology. This tool facilitates, for example, groundwater flow paths, catchment areas assessment, and numerical modelling of geothermal energy prospecting. It is widely used in hydrocarbon and raw materials exploration when analysing the extent and shapes of ore bodies and basins. Furthermore, it finds its usefulness in geotechnical engineering when designing excavations or tunnels, earthquake hazard assessment, and geological mapping to create various geology models.

In the shortest words, Johannes Vind said the meeting was a networking event at its best. It was an exciting and to-the-point event, encompassing numerous conversations and brainstorming sessions on various technical and related social topics. For example, questions related to 3D modelling and policymaking were discussed, as well as better cooperation between geological services of different countries. The more specific subjects took the participants from fault modelling-related bottlenecks to various interpolation methods and even using artificial intelligence in geological 3D modelling problem-solving.

The overarching keyword of the event was 'sustainable society'. And that was quite obviously so due to the challenges we face while using the earth's resources, where geology has a major part to play. The problems of retaining sustainability are often related to energy, carbon dioxide sequestration, critical raw materials, construction, and transport. Therefore, knowing the earth's crust well is more relevant than ever. 3D models help to solve many of the challenges of the earth’s crust and its reasonable exploitation.

Vind explained further that one of the directions geologists must look at these days is creating cross-border 3D models. Geology, in particular dynamic processes such as, for example, the groundwater movement, knows no country borders. Therefore, it is important to move towards merging the models that individual national geological surveys have created so far to get the biggest possible picture of what’s going on below our feet.

The presentation session gave representatives of each participating country to give an overview of the current state of 3D modelling in their homeland. Johannes Vind talked about Estonia, where one current focus in 3D modelling is hydrogeological models. These are represented by the ‘Virumaade’ model and the Estonian-Latvian cross-border groundwater model.

Another topic of importance, which Johannes has been personally occupied with for quite a while, is the regional modelling of local mineral resources. The most recent example is completing the ‘Rakvere and Toolse’ phosphorite deposit model. As a third topic, the first tests have been carried out with the help of a 3D model in presenting geological information to the public.

Important keywords that arose from the presentation session were: 

• voxel modelling as the possibility to add parameters to models,
• 4D modelling as a tool for studying flooding and environmental change impact assessment,
• a more organised approach to geological modelling in different categories,
• increased role of urban geology and planning,
• using AI and machine learning to speed up the processes and data handling,
  
• data uncertainty and reliability of the models for the stakeholders/public.

It echoed throughout the event that when it comes to geological mapping and model-making, we mostly focus on problems related to groundwater availability, geothermal energy, underground space planning, mineral resources, and geological hazard mapping.

In conclusion, the Danish event was very useful for the Estonian delegation. They met the best practitioners in the 3D geological modelling field to date and remained with a strong hope for future cooperation possibilities to emerge from this event. Learning about new software and getting some new technical tricks to apply in their daily modelling tasks was also important. Johannes Vind and Tavo Ani brought home the clear understanding that 3D modelling could and should now be implemented in Estonia's geological mapping, marine geology and geothermal energy fields in the nearest future.