Filing Details

1.	names of Reporting Persons   The D3 Family Fund, L.P.
2.	check the appropriate box if a member of a group			(a) [x] (b) ☐
3.	sec use only
4.	citizenship or place of organization   Washington
NUMBER OF		5.	sole voting power 0
SHARES BENEFICIALLY OWNED BY		6.	shared voting power 195,174 common shares (1.4%)
EACH REPORTING PERSON		7.	sole dispositive power 0
WITH		8.	shared dispositive power 195,174
9.	aggregate amount beneficially owned by each reporting person For the reporting person listed on this page, 195,174; for all reporting persons as a group, 681,206 shares (5.0%)
10.	check box if the aggregate amount in row (9) excludes certain shares ☐
11.	percent of class represented by amount in row (9) For the reporting person listed on this page, 1.4%; for all reporting persons as a group, 5.0%
12.	type of Reporting Person                                                                                  PN

This Schedule 13G reflects the beneficial ownership of the Reporting Persons (as defined below) as of April 19, 2018.

Item 1.

Geospace Technologies Corp. (the "Issuer")

(b)

Address of Issuer's Principal Executive Offices:

7007 Pinemont Dr, Houston TX 77040

Item 2.

(a), (c)

Name of Person Filing and Citizenship:

The names of the persons filing this Schedule 13G (collectively, the "Reporting Persons") are:

·	The D3 Family Fund, L.P., a Washington limited partnership (the "Family Fund");

·	The D3 Family Bulldog Fund, L.P., a Washington limited partnership (the "Bulldog Fund");

·	The DIII Offshore Fund, L.P., a Bahamas limited partnership (the "Offshore Fund");

·	Nierenberg Investment Management Company, Inc., a Washington corporation ("NIMCO") which is the sole general partner of the Family Fund and the Bulldog Fund;

·	Nierenberg Investment Management Offshore, Inc. ("NIMO"), which is a wholly-owned subsidiary of NIMCO and is the sole general partner of the Offshore Fund;

·	David Nierenberg, a United States citizen ("Mr. Nierenberg"), who is the President of each of the two general partners.

NIMCO and Mr. Nierenberg may each be deemed to have voting and dispositive power with respect to the shares of Common Stock (as defined below) held by the the Famliy Fund, the Bulldog Fund and the Offshore Fund.  NIMO may be deemed to have voting and dispositive power with respect to the shares of Common Stock held by the Offshore Fund.

(b)

Address of Principal Business Office or, if None, Residence:

The business address of each of the Reporting Persons is 19605 N.E. 8th Street, Camas, Washington  98607.

(d)

Title of Class of Securities:  Common Stock

(e)

CUSIP Number: 37364X109

Item 3.

If This Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or (c), Check Whether the Person Filing is a:  N/A

(a)

☐

Broker or dealer registered under Section 15 of the Act (15 U.S.C. 78o);

(b)

☐

Bank as defined in Section 3(a)(6) of the Act (15 U.S.C. 78c);

(c)

☐

Insurance company as defined in Section 3(a)(19) of the Act (15 U.S.C. 78c);

(d)

☐

Investment company registered under Section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);

(e)

☐

An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

(f)

☐

An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);

(g)

☐

A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);

(h)

☐

A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)

☐

A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j)

☐

Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

(k)

☐

Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

If filing as a non-U.S. institution in accordance with Rule 13d-1(b)(1)(ii)(J), please specify the type of institution: ____.

If this statement is filed pursuant to Rule 13d-1(c), check this box [x]

Item 4.

Ownership.

(c)       Number of shares as to which such person has:

The Bulldog Fund, NIMCO and Mr. Nierenberg have shared power (A) to vote or direct the vote of, and (B) to dispose or direct the disposition of, the 452,483 shares of Common Stock held by the Bulldog Fund.

The Offshore Fund, NIMO, NIMCO and Mr. Nierenberg have shared power (A) to vote or direct the vote of, and (B) to dispose or direct the disposition of, the 33,549 shares of Common Stock held by the Offshore Fund.

Item 5.

Ownership of Five Percent or Less of a Class.

N/A

Item 6.

Ownership of More than Five Percent on Behalf of Another Person.

N/A

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person.

N/A

Item 8.

Identification and Classification of Members of the Group.

Exhibit 1 hereto is the Joint Filing Agreement among the Reporting Persons dated August 30, 2013 pursuant to which all of the Reporting Persons have authorized the filings under Regulation 13D-G and amendments thereto as a group.

Item 9.

Notice of Dissolution of Group.

N/A

Item 10.

Certification.

By signing below each of the undersigned certifies that, to the best of its or his knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, each of the undersigned certifies that the information set forth in the Statement is true, complete and correct.

	D3 Family Fund, L.P. and D3 Family Bulldog Fund, L.P.
	By:   Nierenberg Investment Management Company, Inc.
April 23, 2018	Its:   General Partner By:   /s/ David Nierenberg              David Nierenberg, President
	DIII Offshore Fund, L.P.   By:   Nierenberg Investment Management Offshore, Inc.
April 23, 2018	Its:   General Partner By:   /s/ David Nierenberg              David Nierenberg, President
	Nierenberg Investment Management Company, Inc.
April 23, 2018	By:   /s/ David Nierenberg              David Nierenberg, President
	Nierenberg Investment Management Offshore, Inc.
April 23, 2018	By:   /s/ David Nierenberg              David Nierenberg, President
April 23, 2018	/s/ David Nierenberg      David Nierenberg