ABOARD THE JOIDES RESOLUTION, IN TRANSIT TO HOBART, TASMANIA– The work of the ship ended as quickly as it started nearly two months ago. We finished drilling Site 1361 and logged the hole. The drillers tripped 3500 meters of pipe and prepped it for storage as the ship will not drill again until July – off the coast of British Columbia. Everyone on board is absolutely brain dead from the non-stop grind of 12-hour shifts day after day. But all are happy as well. We’ve completed most of our objectives and made some exciting discoveries. When we did not meet with complete success it was always because of weather and ice, either encroaching sea ice or fields of icebergs so thick that we had no chance to pass.

Relaxing with some music after the work is done.

Now we have some days in transit. These days are filled with meetings to design our post-cruise research. We will all spend much more time at home working on the cores than our actual days at sea on this expedition. Some of the methods we will employ are expensive and difficult and we have recovered nearly 2000 meters of core. This means that we must carefully select the intervals we will study, so that we can answer the most important questions about Antarctic climate change as quickly as we can. For some of us, the analytical work will extend over the next 4 years. Then other scientists will work on these cores for decades to come. They will be stored in a vast library of ocean cores in College Station, Texas, at the IODP core repository where they are available to scientists from all over the world.

What I like most about these days in transit is going off shift. I no longer set my alarm to awake at 11PM. The two shifts mingle at meals and in the labs, almost as strangers at first as they have not seen much of each other for more than 7 weeks.

The whole team for Expedition 318. Photo courtesy of John Beck, IODP.

Working groups between the shifts assemble to design research strategies and timetables. I will lead a group that will make oxygen isotopic measurements of the small shells of amoeba-like organisms called foraminifera. Forams, as we call them, live for about 4 weeks during the brief Antarctic summer. They build their tiny shells out of calcium carbonate, the main mineral that makes up limestone. By measuring the ratios of two types of oxygen in the carbonate we can tell the temperature of the water in which the forams grew. We will make these analyses on forams that were living in Antarctic surface waters hundreds, thousands, and even millions of years ago to see how warm the water was next to the Wilkes Land coast. We already know from our microscope work on board that this part of Antarctica has been very warm at times, maybe 10 to 15 degrees centigrade warmer when we go back 35 million years. The foram work will help tell us exactly how warm the waters may have been during more recent periods when we know the ice sheet became much smaller. The results will help us predict the behavior of Antarctic ice in the future.

What a trip it’s been! I hope you’ve enjoyed these blogs. If you live in the Bay Area, please look for a notice about a talk I’ll likely give on this expedition in 6 months or so, after we’ve had a chance to start the shore-based part of the work. As we pull ever closer to Hobart we are very much aware that we are simply reaching the end of the beginning.

Christina and Joerg at the bow at sunset. Photo courtesy of John Beck, IODP.

Music by Synthhead. Courtesy of Beatpick.com.

John Weller prepares for a dive in McMurdo Sound.

Alas, on this trip to Antarctica all my underwater exploration has been by proxy through John’s photos and footage, but also through the unique under-ice vehicles SCINI and Endurance. SCINI (Submersible Capable of Under Ice Navigation) is a remote operated vehicle, or ROV, designed and operated by the team of Dr. Stacy Kim and Bob Zook of the Moss Landing Marine Laboratories. We dropped in on a SCINI demonstration the first week we were in McMurdo, an event Bob and Stacy hosted for the community here.

Stacy Kim and Cameo Slaybaugh drilling a hole for SCINI to dive through.

Stacy Kim with SCINI, the ROV that lets her explore under-ice marine ecosystems.

Here’s video of SCINI being deployed through her dive hole:

This slender little ROV, only six inches in diameter, can fit through an eight-inch hole drilled into the sea ice. SCINI is portable (Bob calls it a backpack ROV) so it only needs two or three people to launch and operate it. SCINI’s flexibility allows the science and engineering team to explore very remote places in waters up to 1000 feet (300 meters) deep and inaccessible to SCUBA divers. The ROV is being used by Stacy, who is a benthic ecologist, to study the creatures that live on the bottom (“benthos”) of the ocean. But it’s also a tool that can be used by lots of other scientists in many disciplines. SCINI can provide underwater eyes to ocean sediment coring operations, like ANDRILL, that let scientists see the drill core and properly adjust their setting. It can be also used to map krill distribution for David Ainley’s whale and penguin studies and to map the ocean floor.

SCINI engineer Bob Zook driving the ROV with a game controller.

SCINI being prepared for a dive by Francois Cazenave.

In this video, Stacy explains how SCINI navigation works underwater:

Last year, Bob and Stacy used SCINI to explore some “lost” experiments in McMurdo Sound placed there in the 1960s by benthic ecologists John Oliver and Paul Dayton. Searching the sea floor with SCINI, they were able to locate these tethered experiments and hope to come back next year to collect samples from the sites. This season they took SCINI to three different locations near McMurdo station to study communities of sponges under sea ice and permanent ice shelves and also to explore areas where icebergs have scoured the bottom. For more about Stacy’s research, watch the webcast we did with them in McMurdo.

SCINI with her underwater lights turned on.

I also got a wonderful opportunity to watch the deployment of an underwater bot much larger and more complex than SCINI. Called Endurance (or affectionately dubbed “phatty” by Stacy Kim) this autonomous underwater vehicle, or AUV, was developed by Stone Aerospace and funded by NASA. The research camp at Lake Bonney in the McMurdo Dry Valleys is being run by Peter Doran of the University of Illinois in Chicago with funding from the National Science Foundation.

Traveling by helicopter out to the site, I caught my first glimpse of Blood Falls, a famous feature on the Taylor Glacier first described by British Antarctic explorer Robert Falcon Scott. The striking color comes from an iron-containing salt, ferrous hydroxide, that seeps out of the glacier and stains the water and ice a rusty red. After landing, I strapped ice stabilizers on my boots and headed out on my first walk on a frozen lake. The patterns of the ice were gorgeous.

On the helo trip out to Lake Bonney, we saw glaciers pouring out of the Dry Valleys.

Blood Falls gets its color from iron salts seeping out of Taylor Glacier in the Dry Valleys.

Arriving at a big canvas-covered “garage” on the lake ice, I watched as the roughly spherical-shaped Endurance was deployed. Endurance requires a much larger hole than SCINI and the use of a hoist and several people to guide it into and down the ice hole. Once through the ice, the bot is programmed to take measurements throughout the water column, map the bottom of Lake Bonney and probe for evidence of microbial life. For this experiment, the bot is tethered with a fiber-optic cable that can send photos back to the team in the tent and keep track of its whereabouts.

The Endurance command center on Lake Bonney.

Patterns of ice on Lake Bonney.

Patterns of ice on Lake Bonney.

Enurance is being used in the Dry Valleys LTER (Long Term Ecological Research) program to better understand the ecosystem of Lake Bonney. But a scaled-down version of Endurance could one day probe under the ice of Jupiter’s moon Europa, perhaps the best candidate for finding water and alien microbial life in our solar system.

Endurance is being hoisted to its dive hole.