LAMONT-DOHERTY GEOLOGICAL OBSERVATORY OP COLUMBIA UNIVERSITY Palisades, New York 10964 THE INTEGRAL SOLUTION OF THE SOUND FIELD IN A MULTILAYERED LIQUID-SOLID HALF-SPACE WITH NUMERICAL COMPUTATIONS FOR LOW-FREQUENCY PROPAGATION IN THE ARCTIC OCEAN by Henry W, Kutschale CU1-1-70 Technical Report No, 1 Contract N00014-67-A-0108-0016 with the Office of Naval Research Work done on behalf of the U.S. Naval Ordnance Laboratory, White Oak, Silver Spring, Maryland Reproduction of this document in whole or in part is permitted for any purpose of the U.S. Government. LAMONT-DOHERTY GEOLOGICAL OBSERVATORY OF COLUMBIA UNIVERSITY Palisades, New York 10964 THE INTEGRAL SOLUTION OF THE SOUND FIELD IN A MULTILAYERED LIQUID-SOLID HALF-SPACE WITH NUMERICAL COMPUTATIONS FOR LOW-FREQUENCY PROPAGATION IN THE ARCTIC OCEAN by Henry W. Kutschale CU1-1-70 Technical Report No. 1 Contract N00014-67-A-0108-0016 with the Office of Naval Research Work done on behalf of the U.S. Naval Ordnance Laboratory, White Oak, Silver Spring, Maryland Reproduction of this document in whole or in part is permitted for any purpose of the U.S. Government. February 1970 Digitized by the Internet Archive in 2020 with funding from Columbia University Libraries https://archive.org/details/integralsolutionOOkuts TABLE OF CONTENTS Pages Abstract 1 Captions for Figures 2 Definition of Symbols 3-5 Introduction 6-9 Formal Solution 9-39 Numerical Computations 40-56 Acknowledgements 56 References 57—58 Appendix 59-64 ABSTRACT This report develops by matrix methods the integral solution of the wave equation for point sources of harmonic waves in a liquid layer of a multilayered liquid-solid half space in a form convenient for numerical computation on a high-speed digital computer. Only the case is considered of a high-speed liquid bottom underlying the stack of layers. The integral over wave number has singularities in the integrand and is conveniently transformed into the complex plane. By a proper choice of contours, complex poles are displaced to an unused sheet of the two-leaved Riemann surface, and the integral solution for the multilayered system reduces to a sum of normal modes plus the sum of two integrals, one along the real axis and the other along the imaginary axis. Both integrals are evaluated by a Gaussian quadrature formula. Sample computations are presented for low-frequency propagation in the Arctic Ocean sound channel. These are preliminary computations and the ice layer, which averages three meters in thickness, is not included in the layered system. The effects of the ice layer on propagation are currently under investigation. 2. FIGURES Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Multilayered half-space. Contours for integration. Variation of sound velocity with depth for Model A. Table 2 gives additional parameters for this model. Computations for Model A. Phase - and group-velocity dispersion and excitation function of pressure dependent only on layering. Computations for Model A. Variation with range of the absolute value of pressure for the normal-mode contri¬ bution of the sound field. Source depth 150 m. Hydro¬ phone depth 50 m. Source frequency 10 Hz. Source pressure amplitude 1 dyne/cm re lm. Computations for Model A. Variation with range of absolute value of pressure for the integral contribution of the sound field. Source and detector same as for Figure 5. Computations for Model A. Variation with range of absolute value of pressure of the total sound field. Source and detector same as for Figure 5. Same as Figure 5 but computations carried to longer range. Same as Figure 6 but computations carried to longer range. Same as Figure 7 but computations carried to longer range. 3. Km ; z ; r; t ; oO ; C ; L 9 Xrvn; (fc) Mm/ 22 ^ -fc DEFINITION OF SYMBOLS compressional-wave velocity in the m-th layer shear-wave velocity in the m-th layer thickness of the m-th layer vertical coordinate range between source and detector time angular frequency phase velocity wave number imaginary part of a complex number x + iy velocity potential in the m-th layer normal stress in the m-th layer parallel to z axis pressure in the m-th liquid layer horizontal particle displacement in the m-th layer vertical particle displacement in the m-th layer horizontal particle velocity in the m-th layer vertical particle velocity in the m-th layer density in the m-th layer density at the source. ; Bessel function of order 0 ; Y bessel function of order 0 » O ; K Bessel function of order 0 ; Hankel function of the first kind of order 0 (A'); Hankel function of the second kind of order 0 H 'Kl- k r\ Ov\ k ( K, 'fyy\ YW\. , k > k Piw- 1 , v< V p^=> k > k ? V. -K« fwv ' Zjh. , = 3r Solutions for nr and ( Jb \ nm ^ W /Wv. /Wv. are given by rt*v. 11 . and A n ^ iwt . / t \J kf- i ^wvsL&£ -6u)p /VA (A^e 3t , + A^e. ^ }e where A and A^ are constants. m Placing the origin at the (m-l)-st interface we get ^rw,-r L 1 k ^^ C^/wv'O ( 1 ) ^T*Aya-\~ LUJ P^ l A^ Afwx ) for z = 0 and (Yv\ + O -v- /\ Cr|°£i\v\ ( A^ - A^cosT^ (2 - LVA^p^ (ArVA V ^^ )COS^Rwv - p/vvv ( A fwvA ^ ^^ ?-Vi ^ . for 12 . Substituting expressions for [A m - A^] and [A m + A^] from equations (1) in equations (2) yields C p^vv\ 13 . In general for an (\-layered liquid half-space % • or o « • » ia>\, uo,; since the vertical particle velocity and pressure are continuous across each interface. For the n-th layer 14 . Applying boundary conditions that the pressure vanishes at the surface and that no upgoing waves travel from infinity, (P ZZ ) Q = 0, A r = 0, the relation (3) reduces to t-O k ' -- e"a! - -'V -\ ^0 l ° _ Consider now a solid layer between two liquid layers or at the surface of the laminated halfspace. For this layer we may write (Thomson, 1950; Dorman, 1962 ) « ‘ A* • P- L ( 16 U\, ^** 1 ^ ^^ 43 , U 1 .0 ] 15 . where the fourth element of the column vector is the tangential stress which is zero at a solid-liquid boundary. The matrix elements are given in the appendix and may be derived following Haskell (1953). Equation (4) yields the three equations. — \ AO. rvA -\ A 3, % Substituting A \K WVv.y from equation (5) in equations (6) and (7) yields (A Adding equations (1*0 we get 0 = (J]_]_ + ^21^ ^ + ^ J i2 + ^22^ ^ and ^ We let T = J^]_ + 22\ an< ^ ^ + and solve for X we have (15) 21. Carrying out the matrix multiplication J = E - " 1 A, expressions for T and V are given by A T- v\ V=- A \o \ \ C OJ pr\ A i iK - v. a ' ■v* L oOp, From the first equation of (13) ^jJ " 0 - -(A s Y Kwr'i and (16) from equation (15) Hence, from the second equation of (13) and equations (16) t ^ ve - k 1 ' i 22. Therefore the integral solution for the surface verticle particle velocity is ^ ^ i ^ k — A \8. " J l t K- v * e 0 ■ A 4," t-==, -» tt0 f > 2i ' ai A n cfkM? •V ^3\ ri Pa 7 aT 0 CHOV? A w -V Au \ Cw f *\ V£V^ + /x v a^o O C GO /°° or (x^-(x^ 1 X\^\kr-)kdK O - 3ttlY t In the first integral 28 . 3. ( ~ , \| Vc^-v £* ^ \ co~p *; and therefore ^ \ v # , w^p^A^-CV^^A^' Likewise, in the second integral FC^Vw? 1 ')- F( r C^v? f ') = a * M a\ but A-^-^ ^22 “* A 2 ^21 = ^ CO* 1 " 4 W >*V-(V *-k l )A* Therefore, the integral solution reduces to ,; T . / ^fvK^ lA*.V. H2c-^ht«t£ ^*1 a wp^k^-k** (jA Si ") a ( Vlf^kr ) V dk. Ajf - lk*-k^ A A 29 . From the formulas Hp ctr) = 2~ K 0 C tP) *" a » and multiplying by for a constant pressure top & source of pressure amplitude P Q at unit distance from the source W„- ■V Kftr^-dg o "^^P^L^P^A^-^-vrpAa,! ^ aP 0 to fv'1 k,* ■- v* 7 (A s, >'/, ^tM-Oo^ikcSK ° ^^A* - (Vs< * -kp A* ^ - 3^<1 TRe^ C to For the normal mode contribution, — QTTCy j_ t j_, I— \ C p s * convenient to rev/rite the integral for W Q in the form A + ^V\ c Av> 4- t uJ>p n -s\ < 3 . 30 . where the layer matrices CX / y v>< are defined in the Appendix. There are, as before, simple poles of I 2 along the real axis at for This is the period equation for the laminated half space. From the period equation we write _ / i 00 PnC \ _ | ~ Asu \ V L V A u * - * 2_ k-kjj. But again A-,A 22 - A 21 A 12 = 1, and therefore a U)avi)c G-Q 31 . In summary, the expressions for vertical particle velocity at the surface, vertical particle displacement at the surface, and pressure in a liquid layer are: o c A? - C<-k"> A»n + Q ^ HX^t + _ LOtLO^ C--Cj I + 3TT r t c -C\ n C U) C? f\ P v s„|' n: * « 32 . ^o-ujSL has been used. 33 . For programming it is convenient to write: ur 0 - -Y/^V* - cV/ 3 + cV/^ - l and for the absolute value of vertical particle velocity, a quantity conveniently measured in transmission experiments, Kol- {(.-X Y + £w s -'WsV ‘ where V pn R-v* x , \ T 0 (k Ok d K o |°s W"pXA.,f + ^ fX(Vn (_- A av 'j ^ W=StTT c 3 Y- c3 A" vOel^i C o TV p % Y^p' -? a * + (X<* ♦ s Likewise for vertical particle displacement 35 . v _ A O UJ V\ ^\\ v V* t cVspn.A,^- \ c ^'' ^. Ti^L-Aj ^ ' bc-Liimir,, n, and for pressure 36 . Xi / +*\ ( a-p 0 Pnlk^-k"' I*\Kt-lAi>) a ^ (krXMk ^ W < + ^V V/ 4 ^- 3 -r ? 0 w X^-fo ,\ 3 x ^~ A '£l ^ A M ^"X/wv (j-A^P) 3C Clrw^f^ 'X f 1 W=Va)|. C»C* ? 0 wo x w \r (A^X ^x ^ (A s> \ ^ r X cVsPv,A»ll S^x_ v X ^(-A^ j ScLxw^n, ^ jl « *»*>*. C“Cj_ 37 . The layer matrices for the integral along the real axis are programmed as for solid layers and (a. ^ - w for liguid layers. For the integral along the imaginary axis the matrices are for liquid layers. Likewise, for the ndrmal mode terms the layer matrices are programmed as 39 . for solid layers and for liquid layers. 40 . NUMERICAL COMPUTATIONS Computer programs were written in double precision Fortran 2 IV to compute the pressure in dynes/cm and the vertical particle displacement in millimicrons. The programs are run on the IBM 360/91. For numerical results presented here, computing time was under six minutes. It appears that practical limits of numerical precision make the present development most useful for the Arctic at frequencies below 50 Hz in water depths to 1 km. At higher frequencies or in greater water depths the integrands may be so oscillatory that it is difficult to achieve the desired accuracy in the numerical integrations without excessive computing time. Computations are made in two stages. The first program, an extension of Dorman's (1962) PV 7 dispersion program, computes phase- and group-velocity dispersion, the excitation function depen¬ dent only on layering of the medium, and the excitation function for the particular source and detector depths. In the first case for the m-th normal mode the excitation function is defined by 41 . for vertical particle velocity. In the second case the excitation function is yT/w\ a \ T ^ \ C>A C-* A, 1 w Pn for pressure and lOslO/iH c5 A„a 1 c ^ A u X/w\(rA^ v A 3 c- p C-C /wv. for vertical particle velocity. These definitions were chosen to be ful also at long ranges where VC Ik c) = (% use e va-kr) The second program computes the three integrals, the normal mode contribution to the sound field, and writes and plots the absolute value of 4 \ , or w Q as a 42 . TABLE 1. Model Parameters for Sorensen's (1959) Computations: Source 2 Pressure Amplitude re lm,.3048 dyne/cm ; Source Depth, 15.2 m; Hydrophone Depth, 15.2m; Range, 3.048 m Layer Thickness, m Compressional Velocity, m/sec Shear Velocity, m/sec Density gm/cm 0 18.3 1463.0 0 1.03 Infinite 1609.3 0 1.24 43 . TABLE 2. Integral Real Axis, Real Part F requency, Hz Sorensen’s (1959) Value, dynes/cm 2 Our Value, dynes/cm 2 10 .004713 .004685 20 .030170 .030153 40 .040278 .040485 80 .023193 .023121 160 - .021839 - .022201 320 - .074395 - .074011 44 TABLE 3. Integral Real Axis, Imaginary Part Frequency, Hz Sorensen 1 s Value, dynes/cm^ Our Value, dynes/cm^ 10 - .002567 - .002551 20 - .022260 - .022240 40 - .061960 - .062274 80 - .050986 - .050641 160 - .047979 - .047750 320 .006299 .008316 45 . TABLE 4. Integral Imaginary Axis Frequency, Hz Sorensen’s Value, dynes/cm 2 Our Value dynes/cm 2 10 .095080 .095146 20 .081938 .082076 40 .041887 .041759 80 .030795 .030937 160 .030214 .030356 320 .010593 .011043 DEPTH (M) H6. SOUND VELOCITY (M/SEC) Fig. 3 TABLE 5. Model A Layer Thickness, m Compressional Velocity, m/sec Shear Velocity, m/sec Density, gm/cm3 50 1431). 0 0 1.03 50 1437.0 0 1.03 50 1440.0 0 1.03 50 1443.0 0 1.03 50 1446.0 0 1.03 50 1450.0 0 1.03 50 1453.2 0 1.03 Infinite 1600.0 0 1.20 48 . NOllJNnj NOl LV1I0V3 CD CM (03S/IM ) A1I0013A bO •H fa FREQUENCY (HZ) RANGE (M) 49 . o — Ol o - o o o o Fig. .0001 • • • . .0055 PRESSURE (DYNES/CM 2 ) .0J09 5 RANGE ( M) 50 . o - m o o o o o Fig. 6 RANGE(M) o o“ o .0064 PRESSURE (DYNES/CM 2 ) .0127 Fig. 7 52 . Fig. 8 2000 RANGE (M) 53 . o o*“ o oi o — o o -U o * o o .00027 PRESSURE (DYNES/CM 1 ) .00054 Fig. 9 RANGE ( M ) Fig. 10 5 ^. 55 . function of range. In this program provision is also made to compute the three integrals as a function of frequency or detector depth at a specified range. The integrals are evaluated by Gaussian quadrature formulas (see, for example, Hildebrand, 1956). Care must be taken to employ a sufficient number of Gaussian points to obtain the desired accuracy of the integrals. A thirty-two point Gaussian quadrature formula was found to give sufficient accuracy for the computations presented here out to a range of 1500 m, but at longer ranges, higher frequencies, or greater water depths a ninety-six point formula is used. Abscissas and weight factors for the Gaussian integration are given by Davis and Rabinowitz (1956, 1958). The integration along the imaginary axis extends to infinity, but in practice a finite upper limit is chosen which gives sufficient accuracy. This may be done because the integrand is an exponential function of -kr for large k or r. The programs were checked by computations for the same two-layer model of Table 1 used by Sorensen (1959). Tables 2, 3 and 4 show that the two sets of numerical results are in very close agreement. As an illustration of the progrms for the Arctic, computations were made for the layered model A of Figure 3 , which closely follows the observed variation of sound velocity with depth. Additional parameters for the model are given in Table 5. This is a prelim¬ inary model and the ice sheet, which averages about 3-m in thick¬ ness in the central Arctic Ocean, was not included. The effects of the ice sheet on propagation are currently under investigation. Figure A shows phase - and group-velocity dispersion and the excitation function for pressure. At a frequency of 10 Hz only two normal modes are excited. The range dependence of the absolute 56 value of pressure for the normal mode contribution, the integral contribution, and the total pressure are shown in Figures 5 through 10 . ACKNOWLEDGMENTS Dr. J. Dorman of the Lamont-Doherty Geological Observatory kindly supplied a copy of his PV-7 dispersion program. Computing facilities were provided by the Columbia University Computing Center. This work was supported by the U. S. Naval Ordnance Laboratory and the Office of Naval Research under contract N00014-67-A-0108-0016• 57 . REFERENCES Davis, P. and P. Rabinowitz, Abscissas and weights for Gaussian quadratures of high order, J. Res . NBS , 56 , 35-37, 1956. Davis, P. and P. Rabinowitz, Additional abscissas and weights for Gaussian quadratures of high order: Values for n = 64, 80, and 96, J. Res. NBS , 60, 613-614, 1958. Dorman, J., Period equation for waves of Rayleigh type on a layered, liquid-solid half-space. Bull . Seismol . Soc . Am., 52, 389-397, 1962. Ewing, W. M., W. S. Jardetzky and F. Press, Elastic Waves in Layered Media, McGraw-Hill, New York, 1957. Greene, C. R., Arctic operation of seismic transducers. Sea Operations Department, AC Electronics - Defense Research Laboratories of General Motors Corporation, AC-DRL TR 68-53 , Santa Barbara, California, 1968. Harkrider, D. G., Surface waves in multilayered elastic media I. Rayl&igh and Love waves from buried sources in a multi¬ layered elastic half-space. Bull . Seismol . Soc . Am., 54 , 627-679, 1964. Haskell, N. A., The dispersion of surface waves on multilayered media. Bull . Seismol . Soc . Am., 43 ., 17-34, 1953. Hildebrand, F. B., Introduction to Numerical Analysis, McGraw- Hill, New York, 1956. Kutschale, H., Arctic hydroacoustics, Arctic , 22 , 246-264, 1969. Leslie, C. B., and N. R. Sorensen, Integral solution of the shallow water sound field, J. Acoust . Soc . Am., 33.> 323-329, 1961 . 58 . Pekeris, C. L., Theory of propagation of explosive sound in shallow water in. Propagation of sound in the ocean, Geol . Soc . Am. Memior, 27, 1-117, 19^8. Sorensen, N. R., Integral solution of the shallow water sound field, U. S. Naval Ordnance Laboratory, NAVORD Report 6656 , White Oak, Maryland, 1959. Thomson, W. T., Transmission of elastic waves through a strati¬ fied solid medium, J. Appl . Phys ., 21 , 89-93, 1950. 59 . APPENDIX Matrix elements for normal modes (see Haskell, 1953, and Dorman, 1962). Solid layers =(5^,,=cos,^ ^ A, - ' L \ vv S m\ * c^'JL V C0 ^ (A-Ojs * ^ l ^ C t< + MM. w • VWk.-'X - co^q^ (£W) S ,,- c(V,c . ^ V . s " 2' 3 *"1 ^Ar- ^^'VNT^-Cr^r^-if)S1«Q Liquid layers VS^-fWv'X^ fw^^^ COSV^wv ^ smT^ P*wO _ (A*vx\. = ' 'o^/vv\ Matrix elements for integrals along real axis: Solid layers laA,=^\,- co^- C) • CO^Q^ ^ Q * T \ 61 . Av\ -V % 62 . Liquid layers COS”V^ l a Oi , ^ SlVVf^ ''■' '*\ iv. 5 -M* Matrix elements for integral along imaginary Solid layers Tm - «<& a, - - a (|-^ ^ \\ J vfi -v » “3^ axis: CO^Q^ (£W)^= [ a 0 . t. (£- t + vNU^a- - V~ '(k&F* 3 SMQ^ ** l^^ai ~^'VV\\ ~C COS?^ 4. * Aw 64 . Liquid layers T “ K t k X +T^ 'YA ''WV'IX 1 Cos?^ l^\ x = ^{vg^vV^ ^Vv\ L p/w\ lO ^ \ V\ Corrections Page 7, line 3, should read as follows: in terms of elements of Page 13, line 4, should read as follows: Page 16, line 8, should read as follows: ■&n-, ^ ! & - \ • • • Q t Page 28, line 2, should read as follows: but from the relation A/\ '-I ) ^ V ' ~ ^'3. Aq, “ l \ Page 41, second line, should re< as follows: 3 \ u) v p c~ /a Au 2 A \\ •V TwIrO P*. to-CO, C^c AY\ /V/\ DOCUMENT CONTROL DATA - R & D (Security classi fication of title, body of abstract and indexing annotation must be entered when the overall report is classified) 1 ORIGINATING ACTIVITY ( Corporate author) Lamont-Doherty Geological Observatory of Columbia University 2fl. REPORT SECURITY CLASSIFICATION Unclassified 2b. GROUP Arctic "I’lie 1 integral Solution of the Sound Field in a Multilayered Liquid-Solid Half-Space with Numerical Computations for Low-Frequency Propagation in the Arctic Ocean. 4 DESCRIPTIVE NO T ES (Type of report and inclusive dates) Technical Report 5 authoRIS) (First name, middle initial, last name) Henry W. Kutschale 6- REPOR T DATE February 1970 la. TOTAL NO. OF PAGES 64 lb. NO. OF REFS 13 0a. CONTRACT OR GRANT NO. N00014-67-A-0108-0016 6. PROJECT NO. NR 307-320/1-6-69 (415) 9a. ORIGINATOR’S REPORT NUMBER(S) 9b. OTHER REPORT NO(S) (Any other numbers that may be assigned this report) 10 DISTRIBUTION STATEMENT Reproduction of this document in whole or in part is permitted for any purpose of the U.S. Government. 11 SUPPLEMENTARY NOTES 12- SPONSO RING Ml LI T AR Y ACTIVITY U.S. Naval Ordnance Laboratory, White Oak, Silver Spring, Maryland Office of Naval Research,Washington, 13 ABSTRACT D.C. This report develops by matrix methods the integral solution of the wave equation for point sources of harmonic waves in a liquid layer of a multilayered liquid-solid half space in a form convenient for numerical computation on a high-speed digital computer. Only the case is considered of a high-speed liquid bottom underlying the stack of layers. The integral over wave number has singularities in the integrand and is conveniently transformed into the complex plane. By a proper choice of contours, complex poles are displaced to an unused sheet of the two-leaved Riemann surface, and the integral solution for the multilayered system reduces to a sum of normal modes plus the sum of two integrals, one along the real axis and the other along the imaginary axis. Both integrals are evaluated by a Gaussian quadrature formula. Sample computations are presented for low-frequency propaga¬ tion in the Arctic Ocean sound channel. These are preliminary compu¬ tations and the ice layer, which averages three meters in thickness, is not included in the layered system. The effects of the ice layer on propagation are currently under investigation. DD , F °?„1473 Security Classification Security Classification 1 4 KEY WO R D S LINK A . . LINK 8 LINK C ROLE W T ROLE W T ROLE W T Hydroacoustics Sound field Layered media Matrix Integral solution Digital computer Numerical computations Security Classification LIST OP RECIPIENTS FOR #307320 CHIEF OF NAVAL RESEARCH 02 ATTENTION ARCTIC PROGRAM OFFICE OF NAVAL RESEARCH WASHINGTON, D. C. 20360 DEFENSE DOCUMENTATION CENTER 20 CAMERON STATION ALEXANDRIA, VIRGINIA 22314 DIRECTOR, NAVAL RESEARCH LABORATORY 06 ATTENTION TECHNICAL INFORMATION OFFICER WASHINGTON, D. C. 20390 DIRECTOR, NAVAL RESEARCH LABORATORY 06 ATTENTION TECHNICAL INFORMATION OFFICER WASHINGTON, D. C. 20390 CHIEF OF NAVAL RESEARCH/CODE 480 OFFICE OF NAVAL RESEARCH WASHINGTON, D. C. 20390 DR. LEONARD S. WILSON OFFICE OF CHIEF OF RESEARCH AND DEVELOPMENT DEPARTMENT OF THE ARMY WASHINGTON, D. C. 20315 U.S. ARMY TERRESTRIAL SCIENCES CENTER P. O. BOX 282 HANOVER, NEW HAMPSHIRE 03755 DR. REID A. 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MOIRA DUNBAR DEFENCE RESEARCH TELECOMMUNICATIONS ESTABLISHMENT SHIRLEY BAY OTTAWA, ONTARIO, CANADA DR. A. R. MILNE PACIFIC NAVAL LABORATORY DEFENCE RESEARCH BOARD DEPARTMENT OF NATIONAL DEFENCE ESQUIMALT, BRITISH COLUMBIA,CANADA -3- DR. SVENN ORVIG DEPARTMENT OF METEOROLOGY MCGILL UNIVERSITY MONTREAL 2, QUEBEC, CANADA MR. WALT WITTMANN NAVOCEANO CODE 8050, BLDG. 58, ROOM 206 WASHINGTON, D. C. 20390 DR. G. DALLAS HANNA CALIFORNIA ACADEMY OF SCIENCES GOLDEN GATE PARK SAN FRANCISCO, CALIFORNIA 94118 MR. LOUIS DEGOES EXECUTIVE SECRETARY COMMITTEE ON POLAR RESEARCH NATIONAL ACADEMY OF SCIENCES 2101 CONSTITUTION AVENUE, N, W. WASHINGTON, D. C. 20418 DR. HARLEY J. WALKER DEPARTMENT OF GEOGRAPHY LOUISIANA STATE UNIVERSITY BATON ROUGE, LOUISIANA 70803 CHIEF OF NAVAL OPERATIONS OP-07T DEPARTMENT OF THE NAVY THE PENTAGON WASHINGTON, D. C. 20350 CHIEF OF NAVAL RESEARCH/CODE 484 OFFICE OF NAVAL RESEARCH WASHINGTON, D. C. 20390 MR. M. M. KLEINERMAN 20 ARCTIC SCIENTIFIC PROGRAM U. S. NAVAL ORDNANCE LABORATORY WHITE OAK, MARYLAND 203 90 MR. ROBERT IVERSON GRAVITY DIVISION ARMY MAP SERVICE 6500 BROOKS LANE ROAD WASHINGTON, D. C. 20315 DR. V. J. LINNENBOM NAVAL RESEARCH LABORATORY CODE 7500, BLDG 58, ROOM 246 WASHINGTON, D. C. 20390 DR. ROBERT H. MELLEN U.S. NAVY UNDERWATER SOUND LAB. NEW LONDON, CONNECTICUT 06320 COL. J. 0. FLETCHER DEPT. OF GEOPHYSICS & ASTRONOMY RAND CORP. 1700 MAIN STREET SANTA MONICA, CALIFORNIA 90406 LIBRARIAN, GEOGRAPHICAL BRANCH DEPT. OF ENERGY, MINES & RESOURCES OTTAWA 4, ONTARIO, CANADA DIRECTOR WOODS HOLE OCEANOGRAPHIC INST. WOODS HOLE, MASS. 01823 NORTHERN AFFAIRS LIBRARY KENT-ALBERT BUILDING OTTAWA, ONTARIO, CANADA DR. V. P. MESSLER 4230 EUTAW STREET BOULDER, COLORADO 80302 DR. RICHARD J, WOLD DEPARTMENT OF GEOLOGY UNIVERSITY OF WISCONSIN MILWAUKEE, V7I SCONS IN 53201 DR. DONALD W. HOOD INSTITUTE FOR MARINE SCIENCE UNIVERSITY OF ALASKA COLLEGE, ALASKA 99735 DR. LAWRENCE COACHMAN DEPARTMENT OF OCEANOGRAPHY UNIVERSITY OF WASHINGTON SEATTLE, WASHINGTON 98105 - 4 - DR. DAVID CLARK DEPARTMENT OF GEOLOGY UNIVERSITY OF WISCONSIN MADISON, WISCONSIN 53706 ENVIRONMENTAL SCIENCE SERVICES ADMINISTRATION U.S. DEPARTMENT OF COMMERCE BOULDER, COLORADO 80301 CONTRACT ADMINISTRATOR SOUTHEASTERN AREA, ONR 2110 G STREET, N. W. WASHINGTON, D. C. 20037 OFFICE OF THE OCEANOGRAPHER PROGRAMS DIVISION CODE N-6 732 N. WASHINGTON STREET ALEXANDRIA, VIRGINIA 22314 NATIONAL LIBRARY OTTAWA, ONTARIO, CANADA DIRECTOR OFFICE OF SCIENTIFIC INFORMATION NATIONAL SCIENCE FOUNDATION WASHINGTON, D. C. 20550 LIBRARIAN DEFENCE RESEARCH .BOARD OF CANADA OTTAWA. ONTARIO, CANADA DIRECTOR ARKTISK INSTITUT KRAEMERHUS L. E. BRUUNSVEJ 10 CHA RLOTT ENLUND, DENMARK DIRECTOR NORSK POLAR INSTITUTE OBSERVATOREIGT. 1 OSLO, NORWAY DR. KEITH MATHER GEOPHYSICAL INSTITUTE UNIVERSITY OF ALASKA OFFICE OF NAVAL RESEARCH CODE 427 WASHINGTON, D. C. 20360 CONTRACT ADMINISTRATOR OFFICE OF NAVAL RESEARCH JOHNS HOPKINS UNIVERSITY WHITEHEAD HALL, ROOM 205 34TH AND CHARLES STREETS BALTIMORE, MARYLAND 21218 CONTRACT ADMINISTRATOR OFFICE OF NAVAL RESEARCH BRANCH OFFICE 495 SUMMER STREET BOSTON, MASS. 02210 LIBRARIAN SCOTT POLAR RESEARCH INSTITUTE CAMBRIDGE, ENGLAND LIBRARIAN NAVAL SHIPS SYSTEMS COMMAND TECH. LIBRARY RM 1532, MAIN NAVY BLDG. WASHINGTON, D.C. 20360 LIBRARIAN TECHNICAL LIBRARY NAVY UNDERWATER SOUND LABORATORY FORT TRUMBULL, NEW LONDON,CONN.06320 LIBRARIAN (CODE 1640) U.S. NAVAL OCEANOGRAPHIC OFFICE SUITLAND/ MD. 20390 LIBRARIAN U.S. NAVAL ELECTRONICS LAB. CENTER SAN DIEGO, CALIFORNIA 92152 LIBRARIAN, TECHNICAL LIBRARY U.S. NAVAL UNDERSEA WARFARE CENTER 3202 E. FOOTHILL BLVD. PASADENA, CALIFORNIA 91107 LIBRARIAN, TECH. LIBRARY DIVISION NAVAL CIVIL ENGINEERING LABORATORY PORT HUENEME, CALIFORNIA 93041 DR. JOHANNES WILJHELM DET DANSKE METEOROLOGISK INSTITUT GAMLEHAVE ALLE 22, CHARLOTTENLUND, DENMARK DR. ALBERT H. JACKMAN CHAIRMAN DEPT. OF GEOGRAPHY WESTERN MICHIGAN UNIVERSITY KALAMAZOO, MICHIGAN 49001 -5- COMMANDER, NAVAL ORDNANCE SYSTEMS COMMAND, CODE 03C DEPT. OF THE NAVY WASHINGTON, D.C. 20360 COMMANDER, NAVAL AIR SYSTEMS COMMAND, CODE 370C DEPT OF THE NAVY WASHINGTON, D.C. 20360 COMMANDER, U.S. NAVAL ORDNANCE LABORATORY, WHITE OAK, SILVER SPRING, MARYLAND 20 9.10 Attn: Code 730 2 Code 5331 10 SUPT., U.S. NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA 93940 ATTN; Dept, of OCEANOGRAPHY 2 COMMANDER, U.S. NAVAL UNDERSEA R&D CENTER SAN DIEGO, CALIFORNIA 92132 Attn: CIVILIAN RESEARCH DIRECTOR & COORDINATOR FOR SUB¬ MARINE ARCTIC OPERATIONS COMMANDING OFFICER & DIRECTOR U.S. NAVY UNDERWATER SOUND LAB. FORT TRUMBULL NEW LONDON, CONN. 06320 Attn: DR. R. MELLEN COMMANDING OFFICER U.S. NAVAL WEAPONS RESEARCH & ENGINEERING STATION NEWPORT, RHODE ISLAND 02842 Attn: W. B. BIRCH COMMANDER, U.S. NAVAL OCEANO¬ GRAPHIC OFFICE NAVAL RESEARCH LABORATORY WASHINGTON, D.C. 20390 Attn: CODE 7230 COMMANDING OFFICER U.S. NAVAL RESEARCH LABORATORY WASHINGTON, D.C. 20390 Attn: BURTON HURDLE DIRECTOR,ORDNANCE RESEARCH LAB. P.O. BOX 30 STATE COLLEGE, PENN. 16801 Attn; W. LEISS AC ELECTRONICS DEFENSE RESEARCH IABORATORIES 6767 HOLLISTER AVENUE GOLETA, CALIFORNIA 93017 Attn; B. BUCK C.R. GREENE DIRECTOR GENERAL, DEFENCE RESEARCH ESTABLISHMENT PACIFIC FLEET MAIL OFFICE VICTORIA, B.C., CANADA Attn: A.R. MILNE DIRECTOR GENERAL, DEFENCE RES. ESTABLISHMENT ATLANTIC FORCES MAIL OFFICE HALIFAX, NOVA SCOTIA, CANADA Attn: DR. R. CHAPMAN MC GILL UNIVERSITY PHYSICS DEPARTMENT MONTREAL 2, P. Q., CANADA Attn: Ice Research Project UNDERSEA SURVEILLANCE OCEANOGRAPHIC CENTER U.S. NAVAL OCEANOGRAPHIC OFFICE WASHINGTON, D. C. 20390