Fibre-optic based techniques enable highly precise point and distributed sensing of the full ground motion wavefield including translation, rotation and strain, as well as environmental parameters such as temperature at scales and with a degree of coverage previously unattainable with conventional geophysical sensors. Considerable improvements in optical and atom interferometry enable new concepts for inertial rotation, translational displacement and acceleration sensing. Laser reflectometry and polarisation analysis on commercial fibre-optic cables allow, for the first time, spatially dense and temporally continuous sensing of the ocean’s floor, successfully detecting a variety of signals including microseisms, local and teleseismic earthquakes, volcanic events and ocean dynamics. A significant breakthrough in the use of fibre-optic sensing techniques came from the new ability to interrogate already existing telecommunication cables to high temporal and spatial precision across a wide range of environments. Applications based on this new type of data are numerous, including seismic source and wavefield characterisation with single point observations in harsh environments such as active volcanoes and the seafloor, ambient seismic noise interferometry, earthquake and tsunami early warning, and infrastructure stability monitoring.

We welcome contributions on developments in instrumental and theoretical advances, applications and processing with fibre-optic point and/or distributed multi-sensing techniques, light polarisation and transmission analyses, using standard telecommunication and/or engineered fibre-optic cables. We seek studies on theoretical, instrumental, observation and advanced processing across all solid earth fields, including seismology, volcanology, glaciology, geodesy, geophysics, natural hazards, oceanography, urban environment, geothermal applications, laboratory studies, large-scale field tests, planetary exploration, gravitational wave detection and fundamental physics. We encourage contributions on data analysis techniques, novel applications, machine learning, data management, instrumental performance and comparison as well as new experimental, field, laboratory, and modelling studies in fibre-optic sensing studies.