[1] Univ Texas Austin, John A & Katherine G Jackson Sch Geosci, Bur Econ Geol, Austin, TX 78712 USA
[2] Zhejiang Univ, Sch Earth Sci, Hangzhou, Zhejiang Provin, Peoples R China
[3] Natl Res Inst Astron & Geophys NRIAG, Seismol Dept, ENSN Lab, Helwan, Egypt
[4] Yangtze Univ, Key Lab Explorat Technol Oil & Gas Resources, Minist Educ, Wuhan, Peoples R China