X0306 4 2012-09-04 0 0000866609 ION GEOPHYSICAL CORP IO 0001297501 Hanson R Brian 2105 CITYWEST BOULEVARD SUITE 400 HOUSTON TX 77042-2839 1 1 0 0 President & CEO Common Stock 2012-09-04 4 F 0 5103 6.53 D 120170 D Since the date of the reporting person's last ownership report, there were 34,108 shares of ION common stock; 25,000 unvested shares of an ION restricted stock award; and 75% (or 52,500 shares) of an employee stock option to purchase 70,000 shares of ION common stock, which was granted on December 1, 2008, transferred to his ex-wife pursuant to a domestic relations order. /s/ Debra A. Addington, attorney-in-fact 2012-09-06