November 2102 Expedition - Plumbing the deep blue
Whilst aboard the Pacific Marlin I have been deploying a CTD, which measures the Conductivity, Temperature, and Salinity, as well as other ocean characteristics. The Crew on the vessel referred to the CTD as ‘The Rocket” due to its narrow rocket-like shape. The CTD has a number of sensors, each used to measure a different oceanographic characteristic, such as temperature or salinity. These sensors take a continuous stream of readings whilst being lowered from the surface to the seabed whilst also measuring depth. This essentially gives us a profile of the water column.
I have connected a 400m long rope to the CTD and attached it to a winch at the back of the Pacific Marlin to make the deploying process less tiring. I lower it at a rate of 0.5m per second so that it takes a detailed reading of the water column. On the way back up, when the winch comes into action, it comes back pretty fast!
These profiles, taken over seamounts and banks in relativley shallow water, and off the seamount in over 800 metres of water, give a good indication of the water column structure which can help answer the question as to why the Chagos Archipelago is such a thriving hot-spot for marine organisms. It will also give me a spatial variation in oceanographic parameters from north to south and east to west.
Watch this space for information on our results.
Lewis Fasolo
Since Lewis started his research, I have been with him on the back of the deck, ready with GPS, paper and pen to take the location reading of where he is launching and also the depth of the water along with the time it goes in and out of the water. All this information is vital to keep track of the whole process, but I would say the hardest part is when it is time to retrieve the CTD. When it has been dropped to over 300m, pulling it back up is no easy task. It is exhausting work, especially with the weather on top. As Lewis keeps saying he needs to be in shape when he gets back home, so he is using all this as a form of exercise.
Rudy Pothin
Creole Translation
Letan ki mon abor Pacific Marlin mon pe larg CTD, ki mezir kondiktivite, tanperatir, salinite e osi lezot paramet oseanografik. Bann travayer lo bato i apel li en ‘Roket’ akoz so laform i etwat parey en roket. Sa CTD i annan plizyer sensor, sakenn i pou diferan paramet oseanografi. Sa bann sensor i pran en kontinyasyon mezir pandan ki i pe gany large sorti lo sirfas pou fon lanmer. Sa i esansyelman donn en profil dan delo
Monn konekte en lakord 400m longer avek sa CTD ki gany atase ek en palank deryer Pacific Marlin pou fer li pli fasil ler i gany large e mwen fatigan. to make. Mon larg li apepre 0.5m par second pou li pran en mezir an detay dan delo. Ler ou redi li anler se la ki sa palank i vin an aksyon, me sa i ensignifikan.
Sa bann profil; par lao le de montany anba lanmer (kot pli sek) e osi pa lo sa bann montany i donn en bon endikasyon sa bann striktir dan delo ki kapab ede pou reponn bann kestyon a koman larsipel Chagos i en landwa ki pe fer tre byen an relasyon bann organism marin. I pou osi donn mwan en variasyon dan bann paramet oseanografi sorti Nor pou Sid ek Les pou Was.
Lewis Fasolo
Depi Lewis in komans son resers , monn avek li pare avek GPS, papye ek kreyon pou pran bann diferan lenformasyon parey lokasyon kote i pe larg sa roket e osi fonder ek ler ki i gany large and ranmase. Tou sa i bann lenformasyon vital pou kit en rikord tou sa bann prosedir, me pou mwan keksoz pli difisil i ler ou bwen ranmas sa CTD. Ler in gany large 300m fonder pou redi li abor bao ankor i pa en keksoz fasil. I aktiyelman en louvraz tre fatigan, akote letan move. Me parey Lewis i dir i bezwen dan en letan an bonnsante ler i retournen, alors i pe servi sa koman en legzersis.
Rudy Pothin