5838 20220922115931.0 10.1093/gji/ggs092 DOI SCART-2022-0084 Sarti, Pierguido Intrasite motions and monument instabilities at Medicina ITRF co-location site 2013 We process the total-station surveys performed at the ITRF co-location site Medicina (Northern Italy) over the decade (2001–2010) with the purpose of determining the extent of local intrasite motions and relating them to local geophysical processes, the geological setting and the design of the ground pillars. In addition, continuous observations acquired by two co-located GPS stations (MEDI and MSEL separated by ≈27 m) are analysed and their relative motion is cross-checked with the total-station results. The local ground control network extends over a small area (<100 × 100 m) but the results demonstrate significant anisotropic deformations with rates up to 1.6 mm a−1, primarily horizontal, a value comparable to intraplate tectonic deformations. The results derived from GPS and total-station observations are consistent and point to the presence of horizontal intrasite motions over very short distances possibly associated with varying environmental conditions in a very unfavourable local geological setting and unsuitable monument design, these latter being crucial aspects of the realization and maintenance of global permanent geodetic networks and the global terrestrial reference frame. NO Time-series analysis Reference systems Space geodetic surveys Intraplate processes Europe Abbondanza, Claudio Legrand, Juliette Bruyninx, Carine Vittuari, Luca Ray, Jim Geophysical Journal International 192 2013 3 1042-1051 elodie.brahy@ksb-orb.be https://academic.oup.com/gji/article/192/3/1042/823773 published in REFERD