Microseisms, once regarded as a nuisance, are now a core part of the seismological toolkit. They are a key element of a revolution in passive seismic imagery using noise sources and have been used to generate seismic images in a variety of settings. There is also growing interest in using passive seismic imagery for time-lapse studies, due the continuously available noise sources. Despite these advances there are many unknowns regarding the microseism sources themselves: their detailed locations, their spatial and temporal distribution, the partitioning of the seismic wavefield at the source location. These variables likely affect the stability of seismic ‘noise correlation’ images and play an important role, especially in time-lapse imagery. Microseisms can also be used to determine oceanographic parameters but the relationships are largely phenomenological. In this session we invite theoretical, numerical and observational contributions on microseism generation, the microseismic wavefield, oceanographic parameters derived from microseisms and studies involving the Earth’s hum. We also invite contributions on ‘noise correlation’ imagery that address the limitations of the microseism wavefield in Green’s function reconstruction and the consequences for image quality and time-lapse imagery studies.