jgg     2015 35 (1):  158-161    ISSN: 0412-1961  CN: 21-1139/TG Abnormal Strain Changes Prior to the M7.0 Lushan Earthquake Observed  by a Borehole Strainmeter at Guzan 1 nstitute of Crustal Dynamics, CEA, 1 Anningzhuang Road,Beijing 100085, China 2 uzan Seismic Station, Earthquake Administration of Sichuan Province, Kangding 626001, China Received: 2014-07-05  Revised: null  Online: 2015-02-06 Supporting info