X0306 4 2013-02-19 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 2013-02-19 4 S 0 44594 7.2122 D 118076 D Sale was pursuant to divorce decree and consisted of 66,658 shares of ION Geophysical Common Stock; however, 22,064 shares of the 66,658 shares sold were included in the amount footnoted as beneficially transferred to ex-spouse on Form 4 filed on September 6, 2012 and subsequently revised by Form 4 filed on December 4, 2012. Debra A. Addington, attorney-in-fact 2013-02-20