Comment on "C-program for the calculation of gas hydrate stability zone thickness" by Hanumantha Rao, Computers & Geosciences 25 (1999) 705-707

Hanumantha Rao (1999) has published a quite valuable program to calculate the thickness of the gas hydrate stability zone (HSZ) in the marine environment. The method involved is based on the pressure–temperature equations developed by Miles (1995) from the gas hydrate phase equilibrium diagrams. Unfortunately, a bug occurs in the program, which may lead to some calculations appearing incorrect. Unexpected results will result if the program is run with the input data from the sea-floor with no HSZ. Two rows of data (Row 12 and Row 18) listed in Table 1 in Rao’s paper happen to be the case. We draw the gas hydrate phase diagrams using these data, and find that the