Follow Dr. Katrina Edwards, as she explores the microbial life at the bottom of the Atlantic Ocean
We are two weeks from departure and things are eerily calm and quiet. After the last minute shipping and shopping fiascos and emergencies, it feels like we are in the eye of a hurricane – waiting what will surly be more storming once we get started.
I find myself preoccupied – about ½ my brain is ticking through lists and incessantly worrying, even while I go about my day job. What engineering and hardware emergencies will crop up – what have I forgotten? Have I spent enough time with my kids? Have I packed enough chocolate for 2 months? From the very serious to the trivial, all is preying on my mind and has me checking my lists – more than twice.
My role on this expedition is that of co-chief scientist. The other co-chief scientist is Wolfgang Bach of the University of Bremen, Germany. My good and long time bud, my ideal partner in crime here and now. We’ve been in this together since we dreamed up the project in 2005. Normally, the IODP will select those leaders of a proposed project be chief scientists (not always however) but there needs to be international representation for this very international organization. Turns out, after we cooked up this project together in Woods Hole, Massachusetts, Wolfy took off for Germany and I took off for California. So we remained ideal partners for this expedition all these years later.
What does it mean to be co-chief scientist? Beyond that I know it means 12 hrs a day on shift, and 12 hrs off, and basically calling the shots, I really don’t have a good feeling for what this job entails. I know it will be different from previous US programs I have led. But I otherwise I will be learning – and sharing – as we go along.
A bit more on the site we are drilling – North Pond. I mentioned that this site has been scrutinized by all walks of scientific disciplines since the mid 1970’s – in fact, it was the classic site for examining the structure and composition of the ocean crust – basic geology – back in the days where we were just starting to work out the details of seafloor spreading (not that we’ve got it all nailed down, even today). What drew scientists in then, and still does today, is that this site abides perfectly by the “Goldilocks’ Principal”. Everything about it is just right. Perfectly plain and average globally speaking in terms of geology, hydrogeology, geophysics, and we predict, microbiology. Ah, this site is just right, she says happily. Don’t worry though, I’m not likely to sleep like Goldilocks at this perfect site over the next two months!
We knew this site was perfect for Geology way back when, but one of the most amazing things we learned after drilling was concerning the hydrogeology – how water flows underground at this site. See, the rocky ocean crust is like one gigantic radiator for the Earth. Water flows in or out just about anywhere it outcrops at the seafloor – through volcanic seamounts or other exposed rock – mining the heat of the cooling lithosphere with great efficiency. When they drilled North Pond, this is one of the things we were just figuring out – how water mines heat out of rock. Making a hole at site 395A (I know, we’ve got to come up with a more interesting name) created a “reverse” hydrothermal system – in reverse of what happens at vents at the seafloor, which expel hydrothermally influenced seawater, instead the site started sucking seawater! To the tune of about 1000 liters per hour – for the next 20 years! This is what prompted scientist to seal up this hole with a CORK for further scientific investigation.
Now we enter a new era of investigation – what kind of microbes are in for the ride on this super highway of fluids flowing in and out of the rock below the bottom of the ocean? Stay tuned to find out.
Image: from Edwards, K.J. 2011. Carbon cycle at depth. Nature Geosciences 4: 9-11. (Perspective)