1. Department of Earthquake Science; Institute of Disaster Prevention, Yanjiao Development Zone; Langfang 065201 China
2. Key Laboratory of Active Tectonics and Volcano, Institute of Geology; China Earthquake Administration; Beijing 100029 China
3. Earthquake Administration of Heilongjiang Province; Harbin 150090 China
4. School of Earth Science and Geologic Engineering; Sun Yan-Sen University; Guangzhou 510275 China