Today we deployed the big yellow streamer for the first time. This will record data at a higher frequency than the OBS. The survey is more concentrated in some places for the streamer.
Above: Tim and Stefan beside the tail buoy.
The four pictures below show the tail buoy being deployed.
The next four pictures show: The streamer (3km in length) being fed out to sea. Inside the streamer there are 8 hydrophones in 12.5m groups. All the information received from the hydrophones is added together. Digitizers spread throughout the streamer (you can see them clearly in the pictures as a yellow seethrough part of the streamer) convert the analogue signal from the hydrophones into a digital format. This is then sent straight to a computer where scientists can start to analyse the information. Although scientist can ‘see’ information straight away it can take up to three years to process the information accurately.
The next sequence of four pictures: Birds (red bird-like structures) are attached to the streamer. The wings are at the top and can be controlled (as a pair) from on board. The wings will adjust the height of the streamer in the ocean water. The nearer the streamer is to the sea surface the clearer the image will be but interference from the waves above can cause problems. The deeper the streamer the less clear the image but there is also the advantage of less interference from the waves above.
The airguns are once again deployed. Now they will go off every 20 seconds.
And course the whole procedure is closely monitored by Nigel Egret #nigelegret