Oct 7 - A New Season
RRS James Clark Ross - Diary Update - 7th October 2007
Noon Position - Lat: 20° 14.7' N Long: 025° 01.6 W
Location - 202 Nm from Mindelo, Cape Verde
Total Distance Travelled: 2119.0 Nm from Falmouth, UK
Air Temp: 25.6 °C
Sea Temp: 25.7 °C
The Start Of A New Season
The 27th September marked the start of a new Antarctic season for the RRS James Clark Ross, the seventeenth in her career so far. The evening tide saw us set sail from Immingham on the River Humber. The ship having spent the summer months undergoing a major upgrade to the engine control systems which will help maintain their reliability in the years ahead. The summer period was under the command of Captain Burgan, who along with his crew departed the vessel on the 26th September for a well deserved leave. They were relieved by Captain Chapman and his crew who will be manning the vessel until February 2008.
The weather in Immingham was not quite what we might have expect for mid September, being quite cool with frequent down pours. However we had the prospect of the tropics ahead to sustain us during final preparations for departure. Travelling round the English coast we made our last drop off at Falmouth. This was to disembark some Engineers who had been carrying out final checks on the engine systems before we headed southwards.
The Immingham dock side in the driving rain.
Click to enlarge. ( R. McCabe)
Out into the River Humber after departing
the lock at Immingham.
Click to enlarge. (J. Edmonston)
Our voyage south this year involves a slight deviation to the Cape Verde Islands to allow for a personnel transfer. Diarists have often described in previous voyages that the ship has under taken science during its voyages to and from the Antarctic. This trip is no different and has seen us collecting some core samples for the Royal Netherlands Institute For Sea Research (NIOZ) from the Madeira Abyssal plain. This is an area of the deep ocean to the West of Madeira. Last Thursday and Friday saw us performing these operations and involved taking two sediment cores from the seabed, which at this point was nearly five and a half kilometres below the vessel. I understand that the purpose of this was to obtain more material (mud) from an area first sampled nearly twenty years ago. The activity of coring is quite common to us, but for our new readers a brief summary is described below.
Coring is carried out to collect mud, sorry sediment, samples from the sea bed. Normally the area to be sampled is examined with vessel mounted acoustic equipment (echo sounders) to ascertain the thickness of the sediment on the seabed. The type of corer to be used is then selected, on this occasion we are using a piston corer. This basically involves a long steel tube made up of sections, which allows the length to be varied and has a large weight at the top. The corer is built horizontally along the ship's deck for ease of working. It is then lifted out over the sea, before being rotated into a vertical position. Once vertical and everyone is happy the corer is lifted from its cradle and lowered to the sea bed. The corer used for these operations was twelve metres long and dropped into the seabed under it's 1000kg head weight. As it approaches the seabed a trigger allows the corer to free fall into the sediments from a precise height, on these deployments that was six metres. This might not sound much, but the seabed was soft and allowed over ten metres of sediment to be recovered on each deployment. The pictures below give a idea of some of the shipboard operations involved.
Lowering to the upright.
Ready to go.
Click to enlarge (M. Baas)
Next stop the seabed.
Click to enlarge (M. Baas)
You might be wondering how we then remove the sediment from the corer without cutting the pipe and still have a usable sample. The cunning part is that the steel tube has a plastic tube inserted into it to act as a liner. On recovery this liner is then removed, cut into one metre sections. This can then be split and the sediments analysed. Initial recording and analysis can take place onboard, but after this the cores are stored in a cool room for detailed study in the laboratory ashore.
Now the samples are collected our next stop is the Cape Verde Islands tomorrow. Where we'll carry out an exchange of personnel before heading to the Falkland Islands and Stanley in a couple of weeks time, but first there is the more sunshine (hopefully) and the equator to cross.
This week, probably due to prevailing weather conditions, we have been joined by several small birds flying around the ship. Whilst travelling through the Bay of Biscay some even tried entering the accommodation itself, probably due to the inclement conditions outside. One was obviously successful given the picture below. This was taken by Johnnie Edmonston before we caught and gently evicted our squatter before any damage could be caused. It obviously preferred to watch the weather from inside the winch control room compared to outside.
Checking the weather outside.
Click To Enlarge.
Our voyage south has presented some lovely sunsets so far and I'm sure we're going to enjoy a few more before we reach the Falkland Island. Here is just a taster of things to come.
Sunset heading south.
Click To Enlarge.
So until next week when we should have visited the Cape Verde Islands (briefly) and reached the southern hemisphere once more, I'll bid you farewell.