GNGTS 2017 - 36° Convegno Nazionale

GNGTS 2017 S essione 1.1 27 Interferometry) and GPS satellite constellation, and requires very complex modelling and pro- vides data with delay of some days. The comparison with RLG and VLBI data will validate RLG operation. A unique feature of the RLG array will be to provide almost immediately available the direct information on sub-daily fluctuation of Earth rotation rate, at the same time the array will provide information of the variation of the rotational axis. VLBI makes its observation in the cosmic inertial reference system, while RLG measure the rotation rate in the local co-rotating reference system. Following General Relativity theory, this introduces a slight difference between the two measurements that we intend to put in evidence at a level of accuracy around some 0.1 ppb. A RLG oriented at the maximum Sagnac signal is not sensitive to the angular fluctuation of the terrestrial axis orientation (polar motion). this information can be obtained by the other RLG of the array. References: Belfi J., Beverini N., Carelli G., Di Virgilio A., Maccioni E., Saccorotti G. and Stefani F.; 2011: Rotational seismology by a laser gyroscope , Atti del 30ª Convegno Nazionale GNGTS pp.13-16. Belfi J., Beverini N., Carelli G., Saccorotti G., Stefani F., Velikoseltsev A., Di Virgilio A., and Maccioni E.; 2012: Horizontal rotation signals detected by “G-Pisa” ring laser for the M w =9.0, March 2011, Japan earthquake , J. Seismology 16, 767-776. Belfi J., Beverini N., Bosi F., Carelli G., Cuccato D., De Luca G., Di Virgilio A., Gebauer A., Maccioni E., Ortolan A., Porzio A., Saccorotti G., Simonelli A., Terreni G.; 2017: Deep underground rotation measurements: GINGERino ring laser gyroscope in Gran Sasso, Rev. Sci. �������� �� Instrum. 88 , 034502 doi: 10.1063/1.4977051 Bernauer M.� �������� ��� ��� ���� , � ��� ���� Fichtner A., and Igel H.; 2009: Inferring earth structure from combined measurements of rotational and translational ground motions , Geophysics, 74 (6). Di Virgilio A.D.V., Belfi J., Ni Wei-Tou, Beverini N., Carelli G., Maccioni E., and Porzio A.; 2017: GINGER: a feasibility study, Eur. ����� �� ���� ���� ���� Phys. J. Plus 132: 157. Schreiber K.U., and Wells J-P. R.; Large ring lasers for rotation sensing ; 2013: Rev. Sci. Instrum. 84, 041101 An update GNSS velocity and strain rate fields for Southern Italy G. Farolfi 1,2 , M. Palano 3 , G. Tucci 4 , G. Siligato 5 1 Department of Earth Sciences, University of Florence, Italy 2 Italian Military Geographic Institute, Florence, Italy 3 Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Catania, Italy 4 Department of Civil and Environmental Engineering, University of Florence, Italy 5 GNSS.it, Taormina, Italy Active tectonics in the central Mediterranean is the result of different processes that followed the closure of Mesozoic oceans (Dercourt et al. , 1986; Dewey et al. , 1989), the collision between the Eurasia and Africa plates and the post-collisional collapse of the Apennine belt, along with the simultaneous subduction-retreat of the Ionian lithosphere (e.g. Doglioni, 1991; Faccenna et al. , 2001 and references therein). Geodetic measurements indicate that in Sicily, the Africa-Eurasia oblique convergence is currently occurring at a rate of ~7-8 mm/yr (e.g. Nocquet, 2012, Farolfi and Del Ventisette, 2015 and references therein). The plate boundary along which this convergence is accommodated is fragmented and the deformation is distributed broadly over large portions of the continental lithosphere (e.g. Palano et al. , 2012). Part of the compressional deformation is absorbed offshore of northern Sicily, where seismicity and focal mechanisms reveal a broadly E-W trending thrust belt (e.g. Billi et al. , 2007, 2010). The complex geodynamic processes are also evidenced by the broad extension observed in northern Sicily (Billi et al. , 2010; Palano, 2015), along a coast-parallel mountain range where historical moderate earthquakes, associated with prevailing normal faulting, occurred (Rovida et al. , 2011).