Preseismic deformation associated with the 2014 Ms7. 3 Yutian earthquake derived from GPS data

Based on analysis of the GPS data during 1999–2007, 2009–2011, and 2011–2013 mainly from the Crustal Motion Obseration Network of China, we obtained the GPS horizontal velocity field, the GPS strain rate field, and the profiles across the southwestern segment of the Altyn Tagh Fault zone and its adjacent regions and identified the different characteristics of horizontal crustal deformation fields and profiles during different perods. The results show that, before the Februar 12, 2014, Ms7. 3 Yutian earhquake, the laevorotation deformation along the southwestern segment of the Altyn Tagh Fault zone increased about 3. 3 mm/a during 2011–2013, relative to that in 2009–2011, and the GPS strain rate field distributed in the southeastern segment of the Altyn Tagh Fault during 2011–2013 increased obviously. These abnormal changes may be regarded as precursors to the Ms7. 3 Yutian earhquake.