jgg     2013 33 (增1):  41-44    ISSN: 0412-1961  CN: 21-1139/TG INITIAL FOCAL DEPTH IMPACT ON DEPTH OF DOUBLE DIFFERENCE  EARTHQUAKE RELOCATION 1）University of Science and Technology of China, Hefei 230022 2）Handan Seismostation of Hebei Prince, Handan 056001 3）Hongshan Seismostation of Hebei Prince, Xintai 054000 Received: 2013-01-23  Revised: null  Online: 2013-09-25 Supporting info