We describe measurements of the rotational component of teleseismic surface waves using an inertial high‐precision ground‐rotation sensor installed at the Laser Interferometer Gravitational‐Wave Observatory (LIGO) Hanford Observatory (LHO). The sensor has a noise floor of 0.4  nrad/Hz at 50 mHz and a translational coupling of less than 1  μrad/m enabling translation‐free measurement of small rotations. We present observations of the rotational motion from Rayleigh waves of six teleseismic events from varied locations and with magnitudes ranging from M 6.7 to 7.9. These events were used to estimate phase dispersion curves that show agreement with a similar analysis done with an array of three STS‐2 seismometers also located at LHO.

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