02 August 2014

Routine coring

As I write this the first leg of the cruise (which has two 3-week legs, and a port call in Killybegs in between) is drawing to an end. We’ve been coring for weeks now. And we’re running on routine. Which is good.
By sheer coincidence we have developed different roles within the coring team. If a core comes on deck, you can reasonably predict who cuts it, who holds the end being cut off, who labels the sections, and who puts the data into a spreadsheet. All have their tasks, and all goes smooth!

The BGS hosing down the vibrocorer before taking out the barrel 

When the cores come out of the core scanner and need to be split, measured, photographed, described and packed, we change things around at random. You don’t want to be describing for six hours on end! And it can be a bit stressful on a busy day; if Elke keeps on bringing in cores from the core scanner lab, and new cores are coming on deck at the same time, and there are cores everywhere and we can’t keep up. Unfortunately, it can also be a bit too quiet if there are no new cores coming in; most often, it is just two of us in the lab, and we don’t have a radio. And I can’t sing. I do anyway; one would be surprised how many songs have lyrics that can be made, with a few substitutions, to be applicable to coring. Fortunately, my lab mate Riccardo is more skilled in musical matters. (It tends to be us during such times; the busy time is between 7 and 12, and Kasper has geophysics watch between 8 and 12, while Sara tends to be elsewhere). And once in a while, Elke comes out with a new core section, and as she mans a lab in a container on her own, she tends to be a bit starved for human interaction as well. That helps! 

Too many core sections; where to put them? 

 Riccardo puts away a core that has been fully processed

And once the cores are in, the splitting can be exciting; we know from the cutting into sections what we can roughly expect, but seeing the entire sequence for the first time is quite something else. Opening a core that looked especially promising is nice! In a research proposal you tend to show idealised versions of what’s to come, but sometimes nature is kind and looks just like that. And when we get the kind of sediments we are after, we take whatever looks suitable for 14C dating from those, and sometimes just take entire slabs of sediment out, to sieve later, looking for very small datable material. But we carefully log the duds too. Maybe they’ll be of use to someone else! And logging those can be a bit boring; actually, logging the overlying Holocene stuff on top of our desired (de)glacial sediments can be too. But needs to be done!

James determines the shear strength of an interesting sediment layer

Handling the cores when they come out of the core scanner is largely devoid of practical challenges; sometimes on has to resort to unconventional methods for splitting cores if they are full of rocks or enormous shells or even bedrock, but that’s about it. The real suspense comes from the core equipment; that is under a fair amount of stress, and that sometimes shows. We have had bent barrels, liners that need 8 people to pull them out of the barrel, we have had countless many inverted core catchers (we often keep these as souvenirs; I have one!), and we have had a bolt missing from one of the three legs of the vibrocorer. If we lose a leg of the corer, we lose the ability to core, and the purpose of the cruise. Fortunately, it is a fairly straightforward repair, even though it involved two cranes not otherwise used for coring, and harnesses, and whatnot. And, worst of all, we have had failure of the engine that pulls the barrel out of the sediment. But everything has been dealt with! I hope it stays that way during the second leg.

So far the weather has stayed nice all the way (a bit of rain one night, but still no waves worth mentioning), and we’ve seen little in the way of charismatic macrofauna. I’ve seen two dolphins pay a brief visit one night; that was it. And I’ve seen land a few times; we’ve seen Anglesey (yay!), the Isle of Man, Cumbria, and bits of Scotland. We’ll be seeing Ireland soon!

An unusual sight for leg 1: a winchman in the rain

So only a few days left until port call. And then the second leg. I really look forward to that; we’ll lose a few really nice people, but I trust the people we get in their place are equally nice. And at the moment, the ship is swarming with senior people who have organised this whole trip. There is not very much space for the likes of me to be involved in anything other than the humble work, which is a bit unfortunate, as it is the first leg that covers the region I will be working on. With some people leaving and thereby making space, I will be much more involved in the second leg, even though it will be Durham that deals with that part of the research. But I look forward to sticking my nose in a lot deeper! And not only will it be possible, but I expect it to even be necessary; on the first leg, we have the transect leaders (each transect has a scientific overlord; we’ve done James’ leg and Rich Chiverrell’s), but at least one of the transect leaders of the western transects will not be on board when their transects are done. A bit weird they didn’t drop everything they had in their hands and made sure they would be there, but I’m sure they had their reasons. And it does mean they’ll need all the expertise they can get, and that’s where I come in! I also think I know how to better run a coring team. So I am bristling with ambitions. Bring on the second leg!

A perk of being in the night shift: you get to see the sunrise!

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