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Deep oceanic water is not a homogenous mixture but is made up of several layers of water or water masses originating from different sources. this programme explores the technology used to collect ...the data which provides oceanographers with a picture of the water masses. Animated diagrams show how temperature and salinity measurements enable them to identify the water layers and where they originated. the 1970s has seen a leap forward in the technology available for studying water masses with the development of the Geochemical Ocean Sections Programme (Geosecs). The programme shows how with the aid of specially designed equipment and computer technology oceanographers can not only refine their picture of water masses but also use tracers like Tritum to monitor the speed with which pollutants introduced at surface flow around the oceans of the world.
Metadata describing this Open University video programme
Module code and title: S334, Oceanography
Item code: S334; 04
First transmission date: 20-04-1978
Published: 1978
Rights Statement:
Restrictions on use:
Duration: 00:24:00
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Producer: Jean Nunn
Contributors: Sandie Smith; John Wright; Harmon Craig; Wallace Broecker
Publisher: BBC Open University
Keyword(s): Antarctic bottom; Deep water; Flume tank; North Atlantic; Salinity profiles; Salinity section; Temperature; Tracer; T-S diagram; Water
Footage description: Over film shots of a flume tank experiment which demonstrates water mass layering, John Wright introduces the programme. Film of work aboard the research vessel Discovery II. John Wright (voice over) explains how data on water masses was collected by ships like this between the wars and up to the 1950's. With the aid of a map and an animated graph, John Wright (mostly voice over) examines a temperature and then a salinity profile for data from an Atlantic station near the Equator. He comes up with three stable, stratified layers of ocean water. A temperature salinity (T-S) diagram helps to illustrate his points. Wright shows a model of the Atlantic Ocean into which he places simulated layers of water as determined by hundreds of T-S readings from stations all over the Atlantic. He points out the origins of these masses as he assembles the model. A T-S diagram, part animated, for a cross section of the Atlantic is examined by John Wright (voice over). He points out the primary source for the water mass layers. Using another T-S cross section diagram of the Atlantic, John Wright (mostly voice over) examines secondary sources of water mass layers in the Atlantic. He looks particularly at the Mediterranean as a source of highly saline water. A T-S diagram of the Mediterranean is also shown. Sandra Smith briefly introduces the sequence. Harmon Craig, Scripps Oceanographic Institute, explains the problems involved in organising and carrying out a large systematic water sampling programme such as the American GEOSECS programme. He points to a map of the Atlantic Ocean as he talks. Film shots of research being carried out on board a GEOSECS research vessel at sea. Sandra Smith (voice over) provides the commentary. Shots of the water sampling equipment and of the probes which continually monitor-salinity, temperature and dissolved oxygen. Wallace Broecker, chief scientist on board, points out some of the instruments in the control room. Over more shots of research being carried out on board ship, Sandra Smith continues to describe the equipment and techniques used to gather data on sea water in order to determine where and at what rate water masses are moving. Sandra Smith, with the aid of diagrams (still and animated) discusses the tritium method for determining the origins of water masses and the rate at which they move.
Master spool number: 6HT/72658
Production number: 00525_1296
Videofinder number: 1218
Available to public: no