The magnetic field generated by rock magnetization in the lithosphere carries invaluable information on the past of a terrestrial planet, its evolution, and its tectonic, magnetic and thermal history. To access this information, it is necessary to isolate the lithospheric contributions from the magnetic measurements and to subsequently extract information on the strength and direction of the rock magnetization. This project covers these two aspects. In a first step, we will develop the required tools, that, in a second step, will be applied to Earth and Mars. To this end, we will use CHAMP (Earth) and MGS satellite data (Mars).
Regarding the development of tools, we will adapt processing techniques, which have been previously setup on global scales, to localized systems of representations. These techniques include a previously established method to reduce the influence of non-lithospheric contributions in lithospheric field models as well as a recently published technique to address the non-uniqueness inherent when investigating rock magnetizations. This step will improve lithospheric field models,as their resolution can then be locally adapted. Furthermore, it will help to use locally available geologic information when determining rock magnetizations.
Concerning the data processing, we will first apply the aforementioned global method to reduce the influence of non-lithospheric field contributions to Mars. Subsequently, we will analyse the robustness of Martian paleopole positions, which will be derived using an algorithm accounting for varying intensities of magnetization. In this step, we will make use of the knowledge we obtained when deriving the respective lithospheric field model. Further, the developed localized techniques and algorithms will be applied to the well-known Bangui anomaly on Earth and magnetic anomalies such as Terra Cimmeria on Mars. We expect to be able to provide robust information on the lithospheric magnetization strength and orientation and to link these results to the local geology.
This project is part of the DFG priority programme SPP 1488, "Planetary Magnetism".