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 eighth blog post. To see all her posts, see "60 Seconds in the Mid-Pacific."
SOMEWHERE IN THE EQUATORIAL PACIFIC (APRIL 11, 2009)—We are past the hump—the midway point. We have 16 days of operations left, split between our remaining two sites, and these are followed by a long transit back to Hawaii. We are currently coring at our fourth site, U1334. People are tired and grumpy. Using the new or newly reconfigured science systems and computing infrastructure has been and continues to be harder than anticipated. Doing routine things requires learning new ways, and it often feels like we are all just putting out small brush fires as fast as we can. We struggle to keep our heads above water and to focus on the science of what we are doing. So, what helps to keep our spirits up? And what about that science?
It's obvious—from how I feel, from talking to some folks, from looking at the rest—that we all are feeling the effects of the work schedule. Every one works 12 hours per day, seven days per week for the whole cruise. We miss home, time off, a change in routine. The "wall of pet pictures" has gone up in the lab stairwell. Looking at our own pets and seeing pictures of each other's pets is soothing. It sparks discussions of, "Is your cat really cuter than mine?" and "Whose dog is that one?" We really can't bear to put up the "wall of kid pictures," although obviously we all miss our kids and family members.
Two upcoming events are lifting my spirits. It's the weekend, which you can ordinarily only tell by looking at the calendar, except that the weekend usually features the fire/boat drill. This is when we all practice going to our lifeboat stations—with our hard hats, safety glasses, closed-toe shoes and life vests. Each week we learn something else about the operation and supplies of the lifeboats. The ship's crew takes the opportunity to practice some valuable firefighting or emergency skill, learning their roles and reviewing the procedures to be followed. I like fire and boat drills, because they mark time elapsed and because it's just something different. They usually happen Saturday or Sunday, and signs go up and an e-mail arrives alerting us to this.
I have been wondering what will happen for Sunday's meal. In the past, Sunday often featured a barbecue, with picnic tables on the steel decks and a chance to eat outside, even if it is a bit windy sometimes. These haven't happened yet this cruise, for a variety of good reasons, but I miss them. My answer came today—an e-mail from the captain and a note posted in the galley alerting us that the boat drill will be Monday, and that it is delayed by a day because of the Easter Sunday barbecue. Hooray!! A fancier meal and a change of pace, not because it's a religious holiday, but because it is a good reason for the catering crew to pull out the stops. Tomorrow's noon meal, the one at the end of my shift, should be a barbecue. It's the small pleasures—a can of cold soda, a chance to sit outside and eat, a way to get outside ourselves—that get us through a lengthy expedition.
So, what about that science? Several things this week have helped. We have had science presentations from two of the scientific party, on the big-picture background of science related to this expedition. They have been relatively short (about half an hour), but it has been splendid to hear these and either be reminded of what we might already know and/or to learn something new about why we are here handling this array of sometimes frustrating tasks.
I have been teaching marine geology for over 20 years. I tell students about how the mass balances of the ocean for calcium control the depth distribution of calcite deposition in sediments. How this ledger sheet—an accounting of the sources of dissolved calcium to the ocean and the ways it can leave the ocean—combine with the action of organisms in the ocean and the physical controls on where calcite dissolves to set the fundamental characteristics of marine sediments. The role that movements of tectonic plates play in this: how the vertical subsidence over time, as plates move horizontally away from the ridge crests of their creation, affects sedimentation; how the history of this changing mass balance is reflected in basin-wide sedimentation patterns; and how these are expressed in individual cores. I give homework assignments and test questions, getting students to reason out that they will see layers of clay overlying calcite reflecting these combined effects.
But here, as core comes on board, as it gets split open in half and onto the sampling table, we see these patterns before our eyes. The transition we are looking at isn't new, in the sense that no one has seen it before. We know we are looking for good expressions of this radical change in ocean sedimentation that occurred about 34 million years ago. And we are finding it at our sites, including this one, with lovely recovery of the Eocene–Oligocene boundary.
This site has featured a special treat. The cores are composed largely of calcite throughout much of the site depth. These hard parts of largely planktonic organisms build the sediment fabric, and their predominance in the sediments gives them a typically white to off-white color. At depth in this site, through oxidation reduction processes we are still exploring, it was clear even on the catwalk where the cores are first recovered that the cores at depth were distinctly blue, not just white. We have seen all the cores from the first hole at this site and, at depth, they pass through a range of color: from a pale robin's egg blue to a lovely pale green to a yellow to orange then to tan. In the end we will have a scientific explanation for this, and this isn't the first time that some color has been observed in these type of sediments. Ah, but they are lovely, truly lovely. And it reminds me of the splendors of this world and our enormous joy and privilege in being able to explore these splendors, using the skills and resources of a wide array of individuals on this ship and off it, supporting our efforts.
A barbecue, a boat drill, a reminder that we really don't know it all, and evidence of our interlocking network of needs and support—these combined lift my spirits for another day of doing the tasks in front of me.
Photos of a chunk of basaltic rock from the ocean crust caught in an extended core barrel, and of preparations for launching the ship's air gun into the sea, courtesy IODP