Available online
Description
The chalky deposits of Southern Britain were originally formed underwater as the carbonate skeletons of marine plants and animals fell to the seabed. Today erosion slowly returns that same calcium ...carbonate to the sea. The programme examines three distinct environments where calcium carbonate is now being deposited - the Scottish shelf and slope out at Rockall Bank, the Atlantic Ocean basins and the reefs and lagoons off Florida. The relative importance of those kinds of environments has changed during the geological past, and the programme ends by examining how two factors, sea level and biological evolution, has affected the global deposition of carbonate in the ocean.
The chalky deposits of Southern Britain were originally formed underwater as the carbonate skeletons of marine plants and animals fell to the seabed. Today erosion slowly returns that same calcium ...carbonate to the sea. The programme examines three distinct environments where calcium carbonate is now being deposited - the Scottish shelf and slope out at Rockall Bank, the Atlantic Ocean basins and the reefs and lagoons off Florida. The relative importance of those kinds of environments has changed during the geological past, and the programme ends by examining how two factors, sea level and biological evolution, has affected the global deposition of carbonate in the ocean.
| Module code and title: | S334, Oceanography |
|---|---|
| Item code: | S334; 12 |
| First transmission date: | 31-08-1978 |
| Published: | 1978 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:00 |
| + Show more... | |
| Producer: | P. L. Firstbrook |
| Contributors: | Andy Fleet; Brian Funnell; Julia Hubbard; John Wilson |
| Publisher: | BBC Open University |
| Keyword(s): | Ardnamurchan; Calcareous algae; Calcium; Deep water coral; Florida Banks; Lophelia; Oyster shell; Pisces III; Rockall Bank; Sponge |
| Footage description: | Shots of shoreline chalk cliffs. Andy Fleet introduces the programme. On a map of the world he points out the three areas of carbonate deposition which will be examined. John Wilson, in the studio with a selection of sea shells, explains that these animals take up calcium carbonate from sea water and are also a source of calcium carbonate when they die. Wilson points to a map showing the Scottish continental shelf. Shots of the beach at the are indicated on the map. Close up shots of the organisms found there. Wilson in the studio with a boulder dredged from the continental shelf in this area. The boulder is covered with the remains of carbon producing animals. Wilson pours some shells from one of these boulders on a table and identifies the animals. Wilson examines the deep water coral Lophelia found on the edge of the Rockall Bank. Shots of the submersible 'Pisces' being launched and underwater shots taken from 'Pisces' showing the coral. Wilson, with a specimen of the coral in the studio, examines it in greater detail. Andy Fleet points out the next area for investigation on a map of the Atlantic - an ocean basin area of the North Atlantic. Shots, under magnification, of planktonic life found in this zone. Commentary by Fleet describes the organisms. Fleet explains what the carbonate compensation depth (CCD) is and how and at what depth it is formed in this area of the Atlantic. Julia Hubbard points out, on a map, the next area for study - the Keys area of Florida. Underwater film showing some of the organisms which inhabit the sea here. Aerial shots of reefs. Commentary by Hubbard. More underwater film, this time of the less saline waters of Florida Bay. Also shots of sieved specimens from this area. Commentary by Hubbard. Andy Fleet, pointing to a map and looking at diagrams, discusses the relative importance of the three carbonate sinks examined in the programme. Having determined that there has been a significant shift towards shallower water sedimentation over the past thousand years, Andy Fleet tries to explain why this should be so. An animated map helps to illustrate his points. Using schematic representations of ocean floor core samples, diagrams and an animated graph, Brian Funnell explains how carbonate sedimentation accumulated in the deep ocean basins over the past 100 million years. Funnell goes on, with the aid of an animated map, to suggest a correlation between changes in the sea level height and of the CCD in deep ocean basins. Funnell suggests another factor, increased diversity of coccolithophores, which may have had an effect on the level of CCD. Shots of a graph illustrates his points. |
| Master spool number: | 6HT/72830 |
| Production number: | 00525_1304 |
| Videofinder number: | 882 |
| Available to public: | no |
