Editor's Note: Peggy Delaney is sailing on a newly refurbished research vessel, the JOIDES Resolution, that left Honolulu on March 10 with an international group of researchers on board. The ship, supported by the U.S. National Science Foundation, conducts scientific investigations beneath the seafloor by drilling the ocean floor and retrieving long “cores” of mud for testing and data collection. This is her fifth blog post. To see all her posts, see "60 Seconds in the Mid-Pacific."
IN THE EQUATORIAL PACIFIC (March 22, 2009)—The frequency of my posting has slowed down, because we have been on-site and the pace of work in the chemistry lab has really stepped up.
On the 15th, we arrived at site PEAT1C and started assembling and lowering drill string to the seafloor. That site would become U1331, and we began coring on the 16th. (A word about site naming: When the site is proposed site, it has a site designation particular to the proposal—in this case, PEAT stands for "Pacific Equatorial Age Transect." Different expeditions will have different proposed site designations. Once we start drilling a site, however, it loses its proposed status and gets a formally designated site number.) We recovered 15 cores that day, all of material from Quaternary [period] to middle Eocene epoch, and began processing them. On an initial look, we saw red clay and a nanofossil zone with radiolaria and few diatoms.
The radiolarian-rich sediments look a bit like chocolate mousse. We kept coring for several days. Our initial attempts to core the early Eocene material weren't ideal, but we got a good sample after a few days. We also probably hit the basaltic basement, which, as Katrina Edwards described in 60 Seconds in North Pond, can be quite damaging to cores. In this case it was that coring basement can be damaging to coring tools not especially made for the job. We were using a type of piston corer ideal for recovering undisturbed soft sediment, to get the best sample we could of the carbonate-rich material overlying basement. As a consequence, we ended up getting a sample of basement with this hydraulic piston corer, and the piston corer showed signs of this contact with the very hard basement. This was a creative and effective way to meet program science goals, as we got both a beautiful sediment section and the sample of basement we wanted to have at each site. In the words of our daily scientific report, we surmised that "Core 18H had more than vigorously encountered basaltic basement."
Yesterday, we finished up at U1331, and today we've just arrived at our next site (PEAT2C, soon to be U1332). As part of the transition, we held our science meeting yesterday for each of the groups to give summaries. This is the first formal opportunity for all of the different scientific specialty groups to hear what each other has found. Each group will also be writing their part of the chapter about this site very soon. Remember that we walk off the ship with a near-final version of a small book about this expedition, published for use by the scientific community as an expedition report.
Those of us who have done this before knew where we were driving in the lab programs—toward a complete set of data carefully and fully documenting what we found at this site, with appropriate graphics to support it. This complete set of data is accompanied by first-order interpretations of what the depositional and geochemical, along with the micropaleontological, compositional, physical, magnetostratigraphic and other properties mean in terms of the history of sediment deposition at this site.
One of the real pleasures for me was in seeing the site meeting and this process through the eyes of some of the scientists who are new to this—new to this renovated ship, new to collecting these data in these labs at sea, new to the site chapter writing process. As one said, "We are doing science in real time!"
And this reminded me: Beyond all the struggles of working with new or unfamiliar instruments in a new setting; beyond trying to keep up with the work flow so your lab area isn't the one holding back flow of the core from the catwalk, where the nearly 10-meter (33-foot) core is cut into workable sections with the object of getting it into the containers that will be shipped away from the JOIDES Resolution; beyond 12-hour work shifts, here we are—sampling something no one has ever seen before and doing the first-order scientific description. This really is an amazing process.
My shipboard job is focused on working with the fluids buried with the sediment—the interstitial water. As I was working with samples in the lab, my hand slipped, and I spilled a bit of the precious sample on my pants leg. No big deal—it's chemically very similar to seawater, so no harm done. But then, I thought to myself, "Hey, you just spilled water that was extracted from 40-million-year-old marine sediments on your knee. How many people have ever done that?" And I felt enormously privileged to be given this opportunity to explore the splendors of our world.
Sedimentologists Rebecca Robinson (University of Rhode Island) and Hideto Nakamura (Hokkaido University, Japan) work on a core as Helen Evans (Logging Staff Scientist, IODP-USIO/LDEO) observes. Courtesy IODP