Magmatism
Country / Region: Germany
Begin of project: January 1, 2019
End of project: December 31, 2024
Status of project: September 5, 2023
Deceptively peaceful. Regions affected by Quaternary volcanism are not suitable for a geologic repository for high-level radioactive waste. The Laacher See volcano last erupted 12,900 years ago. The volcanic cinder cones of the Hochstein and Hochsimmer are seen in the background
Source: BGR
People can neither prevent nor influence volcanic eruptions. If a geologic repository for radioactive waste were to be affected by a volcanic eruption, this could have catastrophic consequences for the people living in the surrounding area. The Site Selection Act (StandAG) therefore rules out the construction of a geologic repository in those regions affected by volcanic eruptions during recent geological history, or where volcanic eruptions are expected in future. Volcanic eruptions have to be ruled out for the next million years to guarantee the long-term safety of a geologic repository site.
Reliable forecasts of future volcanic activity depend on a good understanding of the magmatic processes taking place in the earth’s mantle. The volcanoes are actually only the "tip of the iceberg" of long-term geodynamic processes which extend deep in the earth, and which lead to the formation of magma in the earth’s mantle, which then rises up through the lithosphere. These processes have repeatedly led to the eruption of volcanoes in Central Europe in the last 50 million years. The most recent eruptions took place during the present period of geologic history (the Quaternary).
Long-term forecasts are associated with major uncertainties. It is not possible to reliably predict the probability of a volcanic eruption taking place in Central Europe in the next million years. However, volcanic eruptions are just one of several manifestations of the geodynamic processes. A combination of different indicators should therefore help to differentiate areas in which the possibility of volcanic eruptions seems to be more likely to exist than in others. These indicators include:
- Information on past volcanism
- The current status of the earth’s mantle and crust
- Results of numerical simulations of geodynamic developments.
Working together with external experts, this in-house BGR research project aims to develop methods to reach spatially differentiated conclusions on the likelihood of future volcanic activity in Germany. The current state of research on magmatism is compiled and evaluated in interdisciplinary observations.
In addition to this project, BGR published a Short report (May 2019) on the “volcanic activity” exclusion criterion (pursuant to StandAG), for the Bundesgesellschaft für Endlagerung mbH (BGE). Work is carried out on the basis of the Co-operation agreement reached between BGE and BGR. The report reflects on the existing recommendations of the "Working Group On Geologic Repository Site Exclusion Procedures" to outline the regions thought to be affected by future volcanism, the relevant basic data, uncertainties associated with these, and the forecasting options taking into consideration additional indicators.
Two different surveys were carried out to assess the opinions of the scientific community on the possibilities of forecasting volcanic activity in Germany:
- Documentation and evaluation of an expert survey on the long-term forecast of volcanic activity in Germany (Bartels et al. 2020).
- Documentation and evaluation of a second expert survey on the long-term forecast of volcanic activity in Germany (Rummel et al 2021a).
Within the BGR research project “Magmatism”, quantifiable parameters have already been assigned to 15 of the 30 proposed indicators (May 2019; Bartels et al. 2020; Rummel et al. 2021a), which can be implemented to the proposed method by using defined threshold values and buffer zones. The data availability, evaluation and processing are described in detail in the methodology report “Quantification of indicators to forecast volcanic activity in Germany” (Bartels et al. 2022). The resulting spatial characteristics of the parameters form the basis for Germany-wide maps to differentiate areas of possible future volcanic activity as presented in the result report “Germany-wide application of a multi-criteria approach for spatial differentiation of the likelihood of possible future volcanism” (Rummel et al. 2023).
An overview of the current state of knowledge about magma genesis and the geodynamic processes that underlie Cenozoic volcanism in Germany and Central Europe, as well as the factors that can influence past and possibly future volcanism is provided in the report “Cenozoic volcanism in Germany – state of research for geodynamics and magma genesis” (Rummel et al. 2021b). Furthermore, the properties of the volcanic fields in Germany and their rocks as well as the conditions and possible models of magma genesis and development are described there in detail.
The video "Magmatism" provides insights into the methodological approach of the BGR for the prognosis of future volcanic activity in Germany.
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