Meet the…. geochemists!

Hi folks,

Well, what with the ~2 km of core we pulled up in the final days of Exp. 353 there really wasn’t time to upload the final interviews for “meet the scientists” before we hit shore. So here is one of our esteemed geochemists, John, giving us his two cents about his role on the ship… (sorry it’s 3 weeks late, John!)…


Well hello there, and who might you be?

JK: I’m John Kirkpatrick from the USA, and I’m sailing as inorganic geochemist. My home institute is the University of Rhode Island where I’m currently a postdoc.

John waves1

[John sporting some fabulous facial hair around NYE, which sadly became more normal and respectable towards the end of the expedition….]

Jolly good, and what do you do onboard the mighty JR?

JK: I’m sailing as an inorganic geochemist: our main job has to been to extract porewater from the sediment and analyze it for many things, including pH, alkalinity, salinity, dissolved ions (e.g. sodium, magnesium, potassium, calcium, chloride, bromide, sulfate, et cetera), and other elements such as metals.

Ah I was wondering what you were doing when you were squeezing big pieces of the core in that giant vice – you were extracting the pore waters!

johns arm1

[Lab Tech supreme, Vinny, (and John’s hand), show the vice being used to squeeze porewaters out of a “squeeze-cake” taken from the base of each core]

So why exactly is inorganic geochemistry important to the expedition, and why in particular should we care about porewaters?

JK: The dissolved components in sediment porewaters reflect the history of the sediment, its composition, and how the composition came to be – for example, at our earliest site, U1443, there was a lot of carbonate. Where that carbonate came from, though, if it formed organically or inorganically, if it is currently dissolving or precipitating – those are questions that water chemistry can shed light on.

Interesting stuff. I guess we can also see other important things like the depth of the sulfate reduction zone, which will be related to the amount of organic matter in the sediments, among other things, and which will vary from site to site. (See, I do pay attention when the geochems are telling me stuff!).

So tell us about your area of research back home.

JK: My shorebased research involves tying this sort of chemistry to  biological data, typically DNA sequence data. We don’t sequence DNA  onboard, so all of that work is shore-based; plus, DNA analysis is now restricted to samples from international waters or samples that we first obtain permits for.

Yeah, it’d be nice to be able to see exactly what cool bugs we are pulling up from the “dark biosphere” in our cores, but I guess that’ll have to wait for another expedition…

John lab1

[John managing to do an excellent evil scientist impression whilst analysing the porewaters…]

So what is the scientific question you are most hoping to answer with the new material from Exp. 353?

JK: My own pet project, or topic of specific interest, involves the removal  of nutrients – nitrogen – in the sediment by forming N2 gas. Removing nitrogen can take that nutrient out of the biological cycle for a very long time (since N2 gas just floats around in the atmosphere where it is mostly inert). Of course, gases are very ephemeral and so to do these analyses we need fresh, active sediments to incubate and measure under highly-controlled conditions. 80% of the gas in our atmosphere is a
potential contaminant for these measurements!

Yikes, well good luck with that!
So what is the best part about being at sea on the JR for you?

JK: Being away from the day-to-day hustle and bustle of work at the university, the meetings and conferences and emails and stress – we  have a LOT of work to do here on the JR, but it is all focused on a single set of goals; I relish being away from the feeling of being pulled in a hundred directions that I get in my office. Plus, it is a lot of fun getting to know new colleagues!

john twister

[John getting to know new colleagues through the medium of “Microfossil Twister”, surely the most fun game ever (re)invented!]

Good getting to know you too John! And I fully agree with the part about the hustle and bustle – now a full 2 weeks after the end of the expedition, I still have another ~200 emails to plow through before I’m all caught up. Ergh!

Apart from the long hours and the hard work, what do you think is the worst part about being at sea? What do you miss most from home?

JK: I’ve never been apart from my wife this long since I first met her (we  got married last year). Actually now that I think about, never this far apart either – literally on the opposite side of the Earth! I also really miss being able to stretch my legs and go running outside; that always makes me feel better when I’m too busy to think, or feeling a bit down. We have exercise equipment on board, but a treadmill ain’t the same.

Yup, missing loved ones is the pits – hopefully by now you’re all fully reunited, well exercised in the great outdoors and enjoying a break from the office 🙂

Thanks for the insight into the world of the shipboard geochemist, John. Hope to sail with you again!

Coming up soon (well, when I get through these 200 emails, and the rest of the mountain of work that has built up since November!):

-What happens now that the expedition part of Exp. 353 is over?

-When do we all meet up next?

-What are we going to do with all this mud??


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