Ring-laser rotation sensors are contaminated by rotations around horizontal axes (also called tilts) through the vector product between the local normal direction and the vector of the rotation rate composed of Earth’s rotation and local ground rotations. In this study, we investigate theoretically this cross-axis sensitivity and estimate the effects based on magnitude–amplitude relations to be expected for observations of local earthquakes and teleseismic events. We investigate tilt-ring-laser coupling for rotational motions in the P coda of several past earthquakes using tilt motions derived from observed translations. The results show that compared to the corresponding vertical rotation rate tilt-ring-laser coupling is negligible for observations of teleseismic events and for the applicable range of the local magnitude scale.

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