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                                                                    EXHIBIT 10.1


                 THIRD SUPPLEMENT TO NINTH AMENDMENT TO LOAN AND
                               SECURITY AGREEMENT


                               W I T N E S S E T H
                               -------------------

      WHEREAS, the Ninth Amendment (the "Amendment") to that certain Loan and
Security Agreement (as amended, the "Loan Agreement"), dated as of May 11, 1999,
as amended by Amendments Nos. 1-8, among Grant Geophysical, Inc. ("Borrower"),
Elliott Associates, L.P. ("EALP"), as a Lender, and Foothill Capital Corporation
("Foothill"), as Agent (the "Agent") and a Lender (and, together with EALP, the
"Lenders") was entered into by Borrower, EALP and Foothill on January 3, 2003;
each capitalized term used but not defined herein having the meaning given to it
in the Loan Agreement and the Ninth Amendment.

      WHEREAS, pursuant to the Supplement to Ninth Amendment to Loan and
Security Agreement, executed and delivered as of January 22, 2003, the Waiver
Period, as defined in the Ninth Amendment, was first extended through and
including February 5, 2003, and later extended through and including February
21, 2003.

      WHEREAS, Borrower and its subsidiaries and EALP desire that the Waiver
Period, as defined in the Ninth Amendment, be further extended to and including
March 7, 2003.

      NOW THEREFORE, the parties hereto, in consideration of the mutual promises
set forth herein (which are acknowledged to be good, valuable and sufficient
consideration), and each intending to be legally bound hereby, agree as follows:

            1. The Obligors agree, acknowledge and admit that the failure to
remit proceeds of Accounts to EALP as Agent and sole Lender constitutes an Event
of Default (the "Admitted Default") entitling EALP to accelerate all Obligations
immediately and to commence the exercise of remedies under the Loan Documents.
EALP as the successor Agent and sole Lender upon giving effect to the
Obligations Purchase,

      (a)   agrees that the Obligors may retain the proceeds of Accounts
            received by the Obligors (i) prior to and including January 3, 2003,
            if such proceeds have not been turned over, and (ii) from and
            excluding January 3, 2003 through and including 11:59 PM on March 7,
            2003 (the "Waiver Period"); provided, however, that nothing
            contained herein shall allow the Obligors to retain any proceeds of
            Accounts, whether received before, on or after March 7, 2003, at any
            time after the expiration of the Waiver Period;

      (b)   agrees that any payments due on account of the Obligations from and
            after January 24, 2003 to and including March 7, 2003 shall be due
            and payable on March 8, 2003; and

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      (c)   on the condition that no Default or Event of Default (other than the
            Admitted Default) has occurred, agrees for the duration of the
            Waiver Period not to (x) accelerate the Obligations or (y) exercise
            its remedies arising from the Admitted Default.

Nothing contained herein, however, shall constitute a waiver of any other rights
EALP has under the Loan Documents. Without limiting the generality of the
foregoing, EALP specifically reserves its right to enforce, and the Obligors
specifically reaffirm their obligation to comply with, all provisions of the
Loan Documents relating to the continued attachment and perfection of Liens
securing the Obligations on, in or with respect to all of the Collateral,
including without limitation the proceeds of the Accounts.

         IN WITNESS WHEREOF, this Third Supplement has been executed and
delivered as of February __, 2003.

                                         ELLIOTT ASSOCIATES, L.P.,
                                         a Delaware limited partnership,

                                         By: Elliott Capital Advisors, L.P.,
                                             as general partner

                                             By: Braxton Associates, Inc.
                                                 as general partner

                                                 By:  /s/ PAUL SINGER
                                                     ---------------------------
                                                 Name:
                                                       -------------------------
                                                 Title:
                                                        ------------------------


                                         GRANT GEOPHYSICAL, INC.,
                                         a Delaware corporation


                                         By:    /s/ RICHARD F. MILES
                                             -----------------------------------
                                         Name:      Richard F. Miles
                                               ---------------------------------
                                         Title:     President and CEO
                                                --------------------------------


                                         ADVANCED SEISMIC TECHNOLOGY, INC.,
                                         a Texas corporation


                                         By:    /s/ RICHARD F. MILES
                                             -----------------------------------
                                         Name:      Richard F. Miles
                                               ---------------------------------
                                         Title:     President and CEO
                                                --------------------------------


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                                        GRANT GEOPHYSICAL CORP.,
                                        a Texas corporation


                                        By:    /s/ RICHARD F. MILES
                                            ------------------------------------
                                        Name:      Richard F. Miles
                                              ----------------------------------
                                        Title:     President and CEO
                                               ---------------------------------



                                        GRANT GEOPHYSICAL (INT'L) INC.,
                                        a Texas corporation


                                        By:    /s/ RICHARD F. MILES
                                            ------------------------------------
                                        Name:      Richard F. Miles
                                              ----------------------------------
                                        Title:     President and CEO
                                               ---------------------------------



                                        GRANT GEOPHYSICAL DO BRASIL LTDA.,
                                        a corporation organized under the laws
                                        of the Republic of Brazil, South America


                                        By:    /s/ RICHARD F. MILES
                                            ------------------------------------
                                        Name:      Richard F. Miles
                                              ----------------------------------
                                        Title:     President and CEO
                                               ---------------------------------



                                        PT. GRANT GEOPHYSICAL INDONESIA,
                                        a corporation organized under the laws
                                        of the Republic of Indonesia

                                        By:    /s/ RICHARD F. MILES
                                            ------------------------------------
                                        Name:      Richard F. Miles
                                              ----------------------------------
                                        Title:     President and CEO
                                               ---------------------------------


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                                        SOLID STATE GEOPHYSICAL INC.,
                                        a corporation organized under the laws
                                        of the Province of Alberta, Canada

                                        By:    /s/ RICHARD F. MILES
                                            ------------------------------------
                                        Name:      Richard F. Miles
                                              ----------------------------------
                                        Title:     President and CEO
                                               ---------------------------------




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