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Drift Card
Drift Card

Drift Card

Date1950s
Object number00056049
NameCard
MediumPlastic
DimensionsOverall: 77 × 135 mm
ClassificationsTools and equipment
Credit LineAustralian National Maritime Museum Collection Gift of CSIRO
DescriptionA H. J. Nelson Water Sampler captures ocean samples during a deployment from expedition vessels. The samples are analysed on board as well as back on land in a laboratory and serve as references for deployment data whilst abroard. They also help to analyse potential biota captured in samples and the chemical composition of at the depth of deployment. Drift cards (1950s)—superseded drift bottles. These were released at the time of water sampling to further substantiate the direction of current flow. Specific numbers of the cards and the applicable time, data, latitude and longitude were recorded on release from each station. The reverse of the card asked the finder to fill in the time, date and exact location of recovery and return the card to CSIRO. The finder received an award of 25 cents. The release and recovery positions were plotted to indicate direction and possible velocity. SignificanceOcean science practice began in the 19th century, onset by the needs of the first large scale scientific expedition carried out by the Challenger vessel. The Challenger Expedition funded the creation of many new technologies that enabled marine research to begin. This expedition created the need for the first water sampler devices to be made, which have gone through many evolutions of designs since.

Whilst a lot of the early instruments used in ocean monitoring have been superseded by electronic devices, the water sampler has not become obsolete. It continues to serve as a baseline data point that can be reviewed on board and in a laboratory after an expedition. Samples retrieved can be used to calibrate other instruments against and possibly assist as a means to align mismatched data back to its source. The H. J. Nelson device was one version during the long history of samplers and has been part of its evolution to the instruments we use today.