The Equatorial Pacific Process Study (EQPAC) was conducted along 140 deg W
longitude during 1992.
Four cruises took place: February 3 - March 9, March 19 - April 15,
August 5 - September 18, and September 24 - October 21. A fifth benthic
cruise and sediment trap legs were added. During the first cruise
(TT007), 15 stations ... were occupied along 140 deg W longitude from
12 deg N latitude to 12 deg S latitude. During the second cruise
(TT008), data were collected at 8 stations along 140 deg W longitude
from 9 deg S latitude to 9 deg N latitude. During the third cruise
(TT011), data were collected at 15 stations along 140 deg W from 12 deg N
latitude to 12 deg S latitude. During the fourth cruise (TT012), data were
collected at 5 stations along 140 deg W longitude from 17 deg S
latitude to the equator.
To measure oxygen production, water samples were collected with
the trace metal (TM) rosette water sampler using clean techniques. Samples
were incubated in 100 ml quartz bottles at ambient temperature and
irradiance for 24 hours. Net oxygen production was determined from
the change in the oxygen concentration after 24 hours. Gross oxygen
production was determined by measuring the rate at which oxygen-18 labeled
oxygen (O) in water (H2O) was transfered into oxygen-18 labeled O2.
The oxygen data were only collected during the second (TT008) and
fourth (TT012) cruises.
The data is public domain and can be retrieved on-line at