Friday, February 23, 2007

Science Lesson #1: Oceanograph-me

A Masters Thesis entails a lot of work, a lot of work that I don’t want to do right now. It involves painstaking edits and re-edits, draft after draft, looking up and reading boring reference papers just so you can find one factoid to include in your introduction, and so on. It’s a painful and lengthy experience that I’m not looking forward to starting. But I have to start it, so what I’m going to do is take today’s post and make it about my work. You get to learn something new and I get to feel like I actually did something worthwhile.

I am marine geochemist, which is the same as saying I am a chemical oceanographer. There are a couple of things you should know about oceanographers before we begin:

1.) 99.9% of us do not work with whales, sharks, sting-rays, seals, octopi, or manatees
2.) If you meet someone who works with big, dumb sea creatures, chances are they are a trainer at Sea World and NOT an oceanographer.
3.) There are various forums for oceanography – biological, physical, and chemical.
4.) We are the only scientists allowed to be drunk at conferences (Well, not really. But chances are that if you see us at a conference, we are drunk anyway)
5.) Most oceanographers get sea-sick

That’s a few things to start us off with, there are many many more titillating things to know about oceanographers, but I’ll leave you to figure those out on your own.

I’ve been working on a project in the North Pacific with people at the University of Washington in Seattle. The North Pacific has an overabundance of silica, which is what little critters like diatoms make their shells out of. These diatoms live happy but short lives at the surface, then die, and then their shells fall into the deep sea. The silica either redissolves in the water column or gets deposited on the seafloor and makes what we call biogenic opal. The funny thing about the North Pacific is that the excess silica is neither at the surface nor at the seafloor. Excess silica at the surface would mean there are a shitload of diatoms and thus nutrients (and yes, shitload is a scientific term), whereas excess at the seafloor would mean there is a buttload of silica being deposited on the seafloor (scientific as well, thank you). The “plume” as we call it exists at midwater depth – 2300m. For my non-metric minded friends, 1 meter is about 3 feet.

So where is this silica coming from and why is it at this mysterious depth? That’s what I’m working on. I use another element called Germanium to determine if the silica is from the shells of little critters or if the silica is from places like hot vents. Germanium is the downstairs neighbor of silica on the periodic table of elements. When diatoms take up silica to make their shells, just a teeny-tiny bit of Germanium gets incorporated along with the silica. When those shells dissolve, they give back the silica and germanium to the water in a very specific ratio that tells chemical oceanographers like myself “Oooohhh, this silica is from a diatom!”.

If the silica is from hot vents, it is LOADED with germanium. A chemical oceanographer would measure the germanium and silica in the seawater and plot those values against one another on a graph – silica on the x-axis, germanium on the y-axis. If we get an almost horizontal line, we’ve got diatoms. If we get an almost vertical line, we’ve got hot vents.

See, easy-peesy! Now you know something you didn’t know before. Science is awesome.

1 comment:

Tara Armov said...

My brain just exploded.

THANKS KILLTONNNNNNNN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!