29 April 2001 - To be or not TOBI !
RRS James Clark Ross Diary
Noon Position : 15°45' North, 46°54' West, 800 miles from Barbados, or about 54 miles from last weeks position.
Distance travelled since Grimsby: 32,280 nautical miles
Air temperature @ noon: 25.7 degrees Celsius
Sea temperature @ noon: 25.2 degrees Celsius
A Week of Science....
This week has been mostly devoted to a TOBI (Towed Ocean Bottom Instrument) survey of the area that the cruise is interested in. This was in addition to the Swath bathymetry survey taking place at the same time. It's really all a matter of scale as the Swath maps about 3½ times the depth of water, so in this area of the ridge we see a swath of about 10 km wide. Once the main area of interest has been swathed a run with TOBI can be conducted. This gives a sidescan sonar image of the sea bed which is almost photograph like, but as it "flies" about 300m above the sea bed it only sees an area about 6 km wide. Though has been known to "fly" a little Lower when Ian Rouse is the pilot!
As we end the week, Swathing and TOBI have allowed us to pick the juiciest sites where we have observed bare rock. Now it's time for the oriented drill to start and should bring us some rock cores for the science party to work on. These will be up to a metre long and we hope to show the fruits of the labour in future updates.
An update on the dredging mentioned last week. After an initial flourish we seemed to be coating the after deck with a fair amount of mud, sorry, that should read sediment. Having said that our main lab is filling up with sample bags of various sizes so we must be doing something right. Just to prove we did get something below left is the dredge bag being sorted, and right a sample of volcanic rock, the newest part of the earth's crust which is being made all the time right now. Click on images to enlarge.
Below we have a few images from the TOBI week. Click on images to enlarge.
Top Left - TOBI at the ship's stern having the recovery lines pulled onboard, luckily the weather was nice on this occasion. Top Right - The TOBI control centre from where Ian (pictured), Lee and Duncan can monitor TOBI's every move and control it via ship's speed and the towing wire.
Above left - You can tell it must be coming back just by the number of people staring at the wire for the first signs. Above Right - Dave Williams and Derek Jenkins guide TOBI back on deck. It may may look like knitting with all those ropes securing it, but with TOBI weighing nearly two tonnes we don't want to take chances.
It seems we are due to have a bit of a birthday cruise on this occasion with this week's lucky person being Ian Rouse of our TOBI team, so Happy Birthday for last Friday. However, next week it really starts with four more.
On a lighter note... You can always tell when a cruise has lots of people who might not have been to sea before, just by the number of cameras that appear. Below left we have a classic example of the photographer being photographed, though on this occasion I think he was out numbered. Left to right - Martina, Duncan, Javier, Graham, Chris, Richard and Debleena.
Not to be out done the crew came back with this classic "Officer of the Watch" shot (above right) or rather Scott (Third Officer) taking it easy in between science stations.
Thanks this week to Yaoling Niu and David Booth for many of the photographs as the writers were a bit busy, working actually, though some may argue the point.