The main geomagnetic field, which is generated by magnetohydrodynamic processes in the Earth’s liquid outer core, exhibits spatial and temporal variations on a vast range of scales. Observing and modelling the Earth's magnetic field provides valuable insights on the processes and underlying mechanisms responsible for generating and driving its secular variation. Today the most complete mapping of the geomagnetic field is achieved using satellite and geomagnetic observatory data, which are sufficiently dense and accurate to model and detect core field variations on timescales in the order of months. On contrary, changes on the geomagnetic field throughout the Earth's history can be observed only indirectly with help of remanent magnetization in sediments, archaeological artifacts and volcanic rocks. As a result, the paleomagnetic model reconstructions are restricted to centennial, even millennial, time resolutions with an increasing lack of data when going back in time. In that context, this session aims to highlight the newest studies related to geomagnetic field features from the most rapid – geomagnetic jerks – to the most extreme ones – geomagnetic reversals. Therefore, contributions of various timescale variations are welcomed in order to fully characterize the temporal spectrum of the internal geomagnetic field.