Getting busy carrying out the science Toby Tyrrell , January 11 , 2013
Today we got down to business with the first ‘ CTD ’ station . For those of you not familiar with the term , or who don ’ t remember if from one of the previous cruise blogs , CTD stands for conductivity-temperature-depth . Clearer now ? No ??
In practice , it is used to refer to a metal frame which is lowered down into the sea on the end of a metal wire , carrying on board a rack of water sampling bottles ( see picture ). These bottles are sent down with both ends open and are then ‘ fired ’ ( closed ) at specific depths in order to capture water samples from those depths . The metal rack also has some measuring devices attached to it . The complement of measuring devices always includes one for measuring conductivity ( from which the saltiness of sea water , its salinity , is calculated ), one for measuring temperature , and one for measuring pressure ( which tells us about depth ). Hence CTD .
The rosette-sampler / CTD going into the water – with the tubes open . At the selected depth they will be snapped shut to collect a water sample @ Jeremy Young
The CTD was put into the water at about 6:30am and came out again maybe 30 minutes later . Once back on board , a variety of different bottles , pots and carbuoys were brought
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