# First deep underground observation of rotational signals from an earthquake at teleseismic distance using a large ring laser gyroscope

Research paper by Andreino Simonelli, Jacopo Belfi, Nicolò Beverini, Giorgio Carelli, Angela Di Virgilio, Enrico Maccioni, Gaetano De Luca, Gilberto Saccorotti

Indexed on: 22 Jan '16Published on: 22 Jan '16Published in: Physics - Geophysics

#### Abstract

Recent advances in large ring laser gyroscopes (RLG) technologies opened the possibility to observe rotations of the ground with sensitivities up to $10^{-11}$ $\frac{rad}{s}$ over the frequency band of seismological interest (0.01-1Hz), thus opening the way to a new geophysical discipline, i.e. rotational seismology. A measure of rotations in seismology is of fundamental interest for (a) the determination of all the six degrees of freedom that characterize a rigid body motion, and (b) the quantitative estimate of the rotational motions contaminating ground translation measurements obtained from standard seismometers. Within this framework, this paper presents and describes GINGERino, a new large observatory-class RLG located in Gran Sasso underground laboratory (LNGS), one national laboratories of the INFN (Istituto Nazionale di Fisica Nucleare). We also report unprecedented observations and analyses of the roto-translational signals from a tele-seismic event observed in such a deep underground environment.