The depth values in the bottle file have been calculated from pressure
 using the algorithm below.

 The US JGOFS Data Management Office is the source of the calculations.

 The latitude used in computation was the lat_begin of the bottle file.

 The CHECKVALUE was used to verify the accuracy of the computation.

 The stated accuracy of this algorithm is 0.1 meters
 
 Thanks to Edward Peltzer (MBARI) for supplying the algorithm and for
 discussions regarding the computation.



 function DEPTH=depth(P,LAT);

  DEPTH   Computes depth given the pressure at some latitude
          D=DEPTH(P,LAT) gives the depth D (m) for a pressure P
              (dbars) at some latitude LAT (degrees).

          Fofonoff and Millard (1982). UNESCO Tech Paper #44.

  Notes:  (ETP3, MBARI)
          This algorithm was originally compiled by RP @ WHOI.
          It was copied from the UNESCO technical report.
          The algorithm was endorsed by SCOR Working Group 51.
          The equations were originally developed by Saunders
              and Fofonoff (1976).  DSR 23: 109-111.
          The parameters were re-fit for the 1980 equation of
              state for seawater (EOS80).

  CHECKVALUE: D=9712.653 M FOR P=10000 DECIBARS, LAT=30 DEG

  CALCULATON ASSUMES STD OCEAN: T = 0 DEG C; S = 35 (IPSS-78)


  X = sin(LAT/57.29578);
  X' = X*X;


  GR = GRAVITY VARIATION WITH LAT: ANON (1970) BULLETIN GEODESIQUE

  GR = 9.780318*(1.0+(5.2788E-3+2.36E-5*X')*X') + 1.092E-6*P


  D = DEPTH BEFORE GRAVITY CORRECTION

  D = (((-1.82E-15*P+2.279E-10)*P-2.2512E-5)*P+9.72659)*P

  DEPTH = D/GR