jgg     2015 35 (6):  1074-1077    ISSN: 0412-1961  CN: 21-1139/TG A Detection Method of Precursory Anomalies from Big Data  ——A Case Study of the Ludian Earthquake Institute of Crustal Dynamics, China Earthquake Administration, CEA, 1 Anningzhuang Road, Beijing 100085, China Received: 2014-11-04  Revised: null  Online: 2015-12-01 Supporting info