jgg     2015 35 (6):  974-978    ISSN: 0412-1961  CN: 21-1139/TG Research on Recent Tectonic Activity in North Area of Tianjin Earthquake Administration of Tianjin Municipality, 19 Youyi Road, Tianjin 300201,China Received: 2014-11-26  Revised: null  Online: 2015-12-01 Supporting info