As in many areas of science, mathematics has also gained an unprecedented importance in geosciences. The complexity of the processes within the Earth, at its surface, and in the atmosphere can only be described, modelled, mapped, and understood by means of modern mathematical methodologies.   GEM – The International Journal on Geomathematics encourages interdisciplinary research in this respect. It publishes high quality peer-reviewed mathematical papers which are (also) relevant in Earth sciences. This includes all kinds of mathematical methodologies (algebraic, analytic, computational, numerical, operator-theoretic, optimization-based, statistical, stochastic etc.) in every possible discipline of geosciences (such as, but not exclusively, climatology, exploration, fractured porous media modelling, geodynamics, geology, geomagnetics, hydrology, oceanography, satellite data analysis, seismology, solid Earth physics, and time series analysis) but also planetary sciences and cosmology.   While GEM is a mathematical journal, we also welcome research papers from applied scientists who present innovations or enhancements for the mathematical techniques in their expertise. Moreover, we interpret geomathematics in the broader sense that also mathematical novelties for other applications but with applicability in Earth sciences are appreciated. There are numerous areas of applied mathematics with strong interrelations with geomathematics such as fluid dynamics and medical imaging, just to mention a few.   Furthermore, we also strongly encourage the submission of survey articles which build bridges between geosciences and mathematics.