New developments in seismic instrumentation enable highly precise direct point observations of seismic ground motion and its spatial gradients not only in permanent but also in temporary seismic experiments. Considerable improvements in optical and atom interferometry enable new concepts for inertial rotation, translational displacement and acceleration sensing.

Applications of the resulting new type of data are manifold: They include seismic source and wavefield characterization with single point observations in harsh environments like active volcanoes, the ocean bottom and other planets, the correction of tilt effects, e.g. for high performance seismic isolation facilities, as well as seismic ambient noise interferometry and seismic building monitoring.

We invite contributions on novel measurement techniques and experiment design, on theoretical advances to the seismic wavefield gradient analysis, as well as on all aspects of applications of ground motion gradient observations in seismology, geodesy, planetary exploration, gravitational wave detection and fundamental physics.