It all started about 4 years ago, during the pandemic, when we started discussing different studies on pre-seismic observations and we realized that we were both working in the field but basically reading different sets of observational papers and understanding things a bit differently. When we realised that there was no clear study to consult regarding observations before a particular earthquake sequence, we slowly started to do so. We did not know the huge amount of literature we were about to discover. But… voila!! here is our take on it. In this review, we summarize the current state of knowledge on earthquake nucleation and preparation. It has a strong focus on observations from nature, but since the physics behind these processes is best characterised by modelling and experimental work, some important work is also represented here. The diversity among the sequences is overwhelming, not only in terms of physics and tectonic conditions, but also in terms of more technical aspects such as monitoring conditions and the way we have analysed these sequences. The result is a series of physical processes that can operate hierarchically at different spatial and temporal scales, ultimately increasing the stress on the future epicentre. We did put a bit of ourselves in this paper and sincerely hope that you enjoy reading it!
To read our full paper and get a more detailed insight into our research, please click here.