Exhibit 23.3








CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM











We have issued our report dated April 24, 2015 , with respect to the consolidated financial statements of INOVA Geophysical Equipment Limited and subsidiaries as of December 31, 2014, and for the year then ended, included in the Form 10-K/A — Amendment No. 1 to Annual Report on Form 10-K of ION Geophysical Corporation for the year ended December 31, 2014 .  We hereby consent to the incorporation by reference of said report in the following Registration Statements of ION Geophysical Corporation and subsidiaries:





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|-- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|1. | Registration Statement (Form S-8 No. 33-54394) pertaining to the Input/Output, Inc. Amended 1990 Stock Option Plan and Amended and Restated 1991 Outside Directors’ Stock Option Plan,

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|-- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|2. | Registration Statement (Form S-8 No. 33-46386) pertaining to the Input/Output, Inc. 1990 Restricted Stock Plan, 1990 Stock Option Plan and 1991 Directors’ Stock Option Plan,

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|-- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|3. | Registration Statement (Form S-8 No. 33-85304) pertaining to the Input/Output, Inc. Amended 1990 Stock Option Plan and the Input/Output, Inc. Amended and Restated 1991 Outside Directors Stock Option Plan,

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|-- | ----------------------------------------------------------------------------------------------------------------------------------
|4. | Registration Statement (Form S-8 No. 333-14231) pertaining to the Input/Output, Inc. 1996 Non-Employee Director Stock Option Plan,

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|-- | ------------------------------------------------------------------------------------------------------------------
|5. | Registration Statement (Form S-8 No. 333-24125) pertaining to the Input/Output, Inc. Employee Stock Purchase Plan,

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|-- | ----------------------------------------------------------------------------------------------------------------
|6. | Registration Statement (Form S-8 No. 333-80297) pertaining to the Input/Output, Inc. 1998 Restricted Stock Plan,

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|-- | ----------------------------------------------------------------------------------------------------------------
|7. | Registration Statement (Form S-8 No. 333-36264) pertaining to the Input/Output, Inc. 2000 Restricted Stock Plan,

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|-- | -------------------------------------------------------------------------------------------------------------------
|8. | Registration Statement (Form S-8 No. 333-49382) pertaining to the Input/Output, Inc. 2000 Long-Term Incentive Plan,

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|-- | ---------------------------------------------------------------------------------------------------------------------------
|9. | Registration Statement (Form S-8 No. 333-60950) pertaining to the Input/Output, Inc. Non-Employee Directors’ Retainer Plan,

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|--- | ----------------------------------------------------------------------------------------------------------------------
|10. | Registration Statement (Form S-8 No. 333-112677) pertaining to the Input/Output, Inc. 2003 Employee Stock Option Plan,

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|--- | ------------------------------------------------------------------------------------------------------------------------
|11. | Registration Statement (Form S-8 No. 333-116355) pertaining to the GX Technology Corporation Employee Stock Option Plan,

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|--- | -------------------------------------------------------------------------------------------------------------------------------------------------
|12. | Registration Statement (Form S-8 No. 333-117716) pertaining to the Input/Output, Inc. Concept Systems Employment Inducement Stock Option Program,

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|--- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|13. | Registration Statement (Form S-8 No. 333-123831) pertaining to the Input/Output, Inc. GX Technology Corp. Employment Inducement Stock Option Program and the Input/Output, Inc. April 2005 Inducement Equity Program,

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|--- | --------------------------------------------------------------------------------------------------------------------
|14. | Registration Statement (Form S-8 No. 333-125655) pertaining to the Input/Output, Inc. 2004 Long-Term Incentive Plan,

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|--- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------
|15. | Registration Statement (Form S-8 No. 333-135775) pertaining to the Input/Output, Inc. Second Amended and Restated Input/Output, Inc. 2004 Long-Term Incentive Plan,

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|--- | -----------------------------------------------------------------------
|16. | Registration Statement (Form S-3 No. 333-112263) of Input/Output, Inc.,

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|--- | -----------------------------------------------------------------------
|17. | Registration Statement (Form S-3 No. 333-123632) of Input/Output, Inc.,

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|--- | -----------------------------------------------------------------------------------------------------------------------------------------------
|18. | Registration Statement (Form S-8 No. 333-145274) pertaining to the Third Amended and Restated Input/Output, Inc. 2004 Long-Term Incentive Plan,

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|--- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|19. | Registration Statement (Form S-8 No. 333-155378) pertaining to the Fourth Amended and Restated 2004 Long-Term Incentive Plan and the ARAM Systems Employee Inducement Stop Options Program,

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|--- | --------------------------------------------------------------------------------
|20. | Registration Statement (Form S-3 No. 333-159898) of ION Geophysical Corporation,

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|--- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|21. | Registration Statement (Form S-8 No. 333-167943) pertaining to the Fifth Amended and Restated 2004 Long-Term Incentive Plan and the ION Geophysical Corporation Employee Stock Purchase Plan,

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|--- | --------------------------------------------------------------------------------
|22. | Registration Statement (Form S-3 No. 333-166200) of ION Geophysical Corporation,

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|--- | ----------------------------------------------------------------------------------------------------------------------------
|23. | Registration Statement (Form S-8 No. 333-176046) pertaining to the Sixth Amended and Restated 2004 Long-Term Incentive Plan,

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|--- | -----------------------------------------------------------------------------------------------------
|24. | Registration Statement (Form S-8 No. 333-190474) pertaining to the 2013 Long-Term Incentive Plan, and

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|--- | --------------------------------------------------------------------------------
|25. | Registration Statement (Form S-4 No. 333-194110) of ION Geophysical Corporation.




/s/ GRANT THORNTON


Xiamen, People's Republic of China


April 24, 2015