May 5 2008
May 5 2008
Notes from Taryn Noble:
The Coral Team.
Look an island...
We were lucky enough yesterday to see South Georgia.
The coral group get together to discuss plans for our upcoming sampling of the Drake Passage.
Is it an iceberg or is it an island?
Dann Blackwood enjoys a little downtime with a good book.
Meanwhile the geologists from Texas are still sampling the rocky seafloor here in the Scotia Sea.
Hi it’s Taryn Noble. I’m a graduate student six months into my PhD at the University of Cambridge, enjoying this wonderful opportunity to be onboard the N.B. Palmer. This experience is my first proper science cruise and it has so far been brilliant for a number of reasons, hopefully you will have a sense of by the time you’ve read this.
We are in a very interesting region of the world’s ocean in terms of the oceanography, and also for understanding the ocean dynamics in the past. The rough sea conditions and extremely isolated location make it very difficult and therefore expensive to do science down here. So we are very fortunate to be here, which has less to do with luck and more to do with the hard work of the Principal Investigators who made it possible.
The Southern Ocean is unique in comparison to the rest of the world’s oceans. The Antarctic Circumpolar Current (ACC) whips around the continent of Antarctica continuously, undisrupted by land masses. The vigorous flow of the ACC is driven by mighty polar easterly winds and directed by the topography of the seafloor. The ACC mixes waters from the Atlantic with those of the Indian and the Pacific, and has important controls on the distribution and transportation of freshwater, heat, as well as biological and geochemical signals. So in the grand scheme of oceanography the understanding of what is going on in this region is very important with respect to the global ocean circulation. The same is therefore true when trying to understand past ocean circulation during times in the Earth’s history when the climate was different.
My PhD is focused on reconstructing the past hydrography of the Southern Ocean during the deglaciation and last glacial maximum about 20 000 years ago. Using sediment cores to measure geochemical isotopes (such as Thorium, Neodymium, Lead) I will focus around the Cape Basin where southern sourced waters and those of the North Atlantic interact; as well as off the coast of New Zealand where waters carried by the circumpolar current flow into the Pacific Ocean. This cruise is well timed in the course of my PhD. It is has given me a better appreciation for the length of time it takes going from washing the corals brought up in the Blake Trawl to publishing a paper. But mostly it is being confined to a vessel with awesome scientists around me, and nowhere for them to hide from my pestering questions!
Everyday when I wake up and try not to fall from my top bunk, (which is really tricky when sleepy and makes it harder to get out of bed with the challenge of landing softly enough that I don’t get that pin-like feeling in my feet when I jump down too hard) I look outside my porthole for any passing icebergs. It doesn’t really matter how grey it is because I’m not expecting good weather, but today there was beautiful sunshine with a few whispery clouds. Everyone was very excited, as we were only about 70 nautical miles away from South Georgia, a half moon shaped island in the eastern Scotia Sea. This certainly made a change from the Antarctic seabirds, penguins, and icebergs we have seen so far into the trip. We are quite far east, out of the iceberg path so there weren’t as many floating around today as there has been, but there were two quite large and jagged icebergs framing the sharp peaks of South Georgia; the highest of which is at least 3000m! I spoke with Ian Dalziel (Principal Investigator from the University of Texas in Austin), and gleaned some information from him: The island is made of sandstone turbidites (deposited by underwater flows called turbidity currents moving down the continental slope) and according to the magnetic anomaly data, and matching geology, used to be connected to the southern Andes about 100 million years ago, in the mid Cretaceous period. I think it’s a really cool marker for thinking about the magnitude of change caused by plate tectonic activity.
The other excitement today was our team meeting and photo that I am sure you will all enjoy.
We have had very calm seas this week with light winds, and the Palmer is such a sturdy boat that sometime it is easy to forget that you are on a ship in the Southern Ocean. The geologists are busy working up here in the Scotia Sea, and so we have at least one more week of multi-beaming and dredging for rock from the seafloor before we head towards Elephant Island (where we expect to see proper Drake Passage seas and definitely stronger currents). Tina and I have been packing boxes (that Zim and John made so nicely for us) of corals and manganese nodules and tidying things away in anticipation of our up and coming trawls.
Two dredges came up today too: the first had a couple of very large rocks that the Marine Technicians tried very hard to get out, using the winch. In the end in good old geology fashion a crow bar and sledgehammer was taken to the rock, to force it through the mouth of the dredge. The second was very successful in terms of the amount of material that came up, as the whole of the chain net was full of rocks!
My dream job as a kid was to have some kind of outdoor-explorer type job travelling around the world and learning new things all the time. It wasn’t until about my third year of University, when I did a summer fellowship at WHOI, and met awesome people, that I realised that there were people who did exactly that! I am very grateful to Laura Robinson for this amazing Drake Passage adventure and for the excellent examples around me of how to go about being young successful women in science.