Difference between revisions of "CTD monitor"

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(Created page with "The first example I picked was a CTD Monitor. CTD Monitor is a metal instrument which gets dropped down from an amazing buoy. There will be 10 or 12 CTDs which are arranged in...")
 
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The first example I picked was a CTD Monitor. CTD Monitor is a metal instrument which gets dropped down from an amazing buoy. There will be 10 or 12 CTDs which are arranged in a ring, and they get dropped, and sink to the bottom of the ocean. And then at some point, on a timer, they are released, and they will rise. And as they rise, their little metal mouths will open up and grab a gulp of sea water at a particular level. The mouths will close and they will proceed to the top and at some point they will be collected and this happens over a certain time period. Its testing for salinity, its testing for temperature, its testing for depth. Salinity is measured by conductivity and hydrostatic pressure I think.
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Picture a column, starting at the surface of the ocean and descending to the ocean floor. Conceptualised by the discipline of oceanography, this is the area delineated for measuring qualities of the water, an architecture of modernity. A CTD is an instrument commonly used by oceanographers, which measures conductivity, temperature and depth within this region of water. It can gather high resolution data, however it can only do one cast at a time on the sample site – and many casts are needed to provide a picture of an ocean environment. By measuring hydrostatic pressure, compression, pressure, and local gravity field at a certain latitude, depth can be calculated. Then conductivity, temperature and depth are used to calculate water salinity. A CTD utilises sampling bottles, which close at different depths, by dragging the measure upwards through the water, a profile of the water column is created.  
  
This logic follows long history of the way that the seascape is carved up, which the CTD instruments will rise through. Originally, it would have been a hemp rope, weighted with lead, which would be dropped from the side of a ship, As it drops, it runs through the hands of the sailors. There are knots on the rope, and each knot represents a fathom, and the fathoms are called out, and someone marks them with a quill pen.
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This logic follows long history of the way that the seascape has been imagined by different disciplines of Western science. CTD instruments which now rise through these vertical delineations, are preceded by hemp ropes, weighted with lead, which would be dropped from the side of a ship. As the rope dropped, it ran through the hands of the sailors. Knots on the rope, representing fathoms, were called out, and marked down with a quill pen.
  
Through the architecture of Modernity, oceanography has the way of imagining the sea as a column. The sea is a very unstriated space that is imagined as an unchanging space. Even until today, this is how information is collected. Even the more unusual forms of data collection, such as the mini CTDs that are glued onto the heads of seals (a lot of the arctic data is from different seals who swim around). There is a GPS attached to it, and it still logged even though the seal is still swimming happily with that thing glued to its head. The sea is still divided up into a grid, at a certain depth, what is the salinity, temperature and conductivity, for example.
 
 
So, even when sea mammals are put to work doing scientific investigation, and this investigation is then recalibrated into what is fundamentally a giant technological system formed on axes, really. It really brings home the quite strict ontological ground for sea exploration, and the types of relationality that happen in a vast expanse of many different types of sea lives, and many different kinds of waters. Under sea vents, tectonic plates, underwater volcanoes, ecologies which are then being programmed into fundamentally the same model. The data are being used not to explore something different, but to expand Western knowledges along an axis.
 
 
[[category: Instruments]]
 
[[category: Instruments]]

Revision as of 09:13, 16 April 2022

Picture a column, starting at the surface of the ocean and descending to the ocean floor. Conceptualised by the discipline of oceanography, this is the area delineated for measuring qualities of the water, an architecture of modernity. A CTD is an instrument commonly used by oceanographers, which measures conductivity, temperature and depth within this region of water. It can gather high resolution data, however it can only do one cast at a time on the sample site – and many casts are needed to provide a picture of an ocean environment. By measuring hydrostatic pressure, compression, pressure, and local gravity field at a certain latitude, depth can be calculated. Then conductivity, temperature and depth are used to calculate water salinity. A CTD utilises sampling bottles, which close at different depths, by dragging the measure upwards through the water, a profile of the water column is created.

This logic follows long history of the way that the seascape has been imagined by different disciplines of Western science. CTD instruments which now rise through these vertical delineations, are preceded by hemp ropes, weighted with lead, which would be dropped from the side of a ship. As the rope dropped, it ran through the hands of the sailors. Knots on the rope, representing fathoms, were called out, and marked down with a quill pen.