Life on the JR: we still have pineapples!

We have been drilling down hundreds of meters into the seafloor and we have been processing a lot of core. At the moment we are waiting on ice, so time for another blog post.

Imagine you are staying at your work, school or university building for two months without the ability to run to a store and shop. Your friends and colleagues are with you, but not your family. When you look out of the window you see the most beautiful scenery with icebergs and when you step out on the balcony you can sometimes observe the breathing spouts of a group of humpback whales. That is what it is like to be on the JOIDES Resolution in the Amundsen Sea near Antarctica, but our balcony is the deck and we are a long way from home.

We are a total of around 120 people who work different shifts. We are drillers, scientists, operation managers, laboratory techs, engineers, ship navigators, ice watchers, artists, educators and human services personnel, etc., and we all have an equally important part in this whole operation. The nightshift works from midnight to noon and has breakfast, lunch and dinner together at odd times. We also celebrate birthdays: here a picture of Thomas the nightshift paleomagnetist on his birthday last week (photo from Tim Fulton). There was a really nice cake and it was a joyful celebration.

Today we learned from Steve, the chief steward, about the 15 people who keep us happy and allow us to do work 12 hours each day. They do an excellent job preparing and serving our food, doing our laundry and cleaning our rooms and common areas. We also learned from Steve how much planning goes into a shipboard expedition with 120 people with no opportunity to shop for food for two months. You can bring bananas for the first week, but after one week bananas go bad so you need to come up with some other fresh fruit for people to eat the remaining 7 weeks. In his food purchase for two months, Steve makes an educated guess about what kind of food people might like and takes into account that in Antarctica people eat more food to keep warm, especially those who work outside.

Apples and pears can last pretty long and we still have them along with slices of cantaloupe, but the fresh pineapple chunks had been extremely popular after the bananas had disappeared. Unfortunately, the last couple of days we noticed a decline in the pineapples among the cut fruit and we began to worry. Luckily, today as Steve took the nightshift lab folks on a tour of the kitchen and food stores, we could see with our own eyes that we still have pineapples! (I also found out that my cabin is across from the store room with the Oreo cookies in it, but the door has a pad lock on it….) By now most of the fresh vegetables we are served are hardy ones, like carrots and cabbage. But today we had hamburgers with fresh tomato slices! That is pretty amazing, considering that we left port a month ago. We are taken care of really well, thanks to Steve and his team.

Dancing with icebergs: the re-entry cone

Due to the unexpected erratic movements of icebergs, we have had to pull the drill bit up in the hole or even out of it above the seafloor many times in the past week. The ship is unable to move with the drill pipe stuck in the seafloor and it takes time dismantling the stands of pipe so that it is short enough to hang free above the seafloor. Only when the pipe is hanging free, the ship can move. Therefore, if an iceberg comes within a mile of the ship it is closely monitored and a set of safety measures take effect, which include raising the drill string out of the hole. Typically, if there is enough time and the iceberg keeps approaching slowly, a large approximately 3-m (10-ft steel) funnel is lowered over the drill pipe to the seafloor. Unfortunately, icebergs have been coming at us at higher speed than expected and with unpredictable paths, so we have not been able to deploy a free-fall funnel. Finding back the drill hole without a free-fall funnel after leaving the location is very difficult, and if it takes too long, the hole will cave in.

Rest assured: engineers here on board can fix EVERYTHING (I am not exaggerating). So, the crew got to work to build a re-entry platform, so that we can find the hole more easily and make it more stable so we can move the drillstring in and out if we need to move the ship for icebergs. It took some time to put the re-entry platform together, but it was launched a few hours ago. The re-entry system consists of a free-fall funnel attached to a platform with an 11-m long pipe that is large enough to fit the drill string. The platform serves as a mud skirt, making sure the funnel doesn’t sink too far into the fluffy sediment at the top of the seafloor.

The moonpool is a hole in the middle of the ship through which the drill string passes. To launch the re-entry system, the doors of the moonpool had to be opened wide for the platform to pass through. This was a tricky operation, because we are also currently operating in high waves, but Bubba, the toolpusher, and his crew are very experienced. The spectacle of launching the re-entry cone was watched by many science party members. Everyone was freezing, but it was worth it (The drill crew who are out there everyday in the wind and snow deserve a lot of respect). After the launch it took the funnel and platform about 17 minutes to get to the bottom of the ocean, sliding down along the drillpipe for about 4 km. The funnel has a white interior, like a target, so that it is easy to find if a re-entry is needed. Now fingers crossed and let’s hope it works!

Ancient icebergs and polar oceans

The team I am part of on board the Joides Resolution, is the Sedimentology team. We have several jobs: one is to X-ray the core sections that come up to see if something interesting is embedded inside. Once the X-rays look good, the cores are split into half sections across the length of the core and we describe the mud and layering we see. We also take smearslides and look at minerals and microfossils. The shipboard lab has special tables to lay out the half core sections so that we can see the layering inside and any disturbance of the layering caused by drilling. The Sedimentology team also uses instrument tracks to take full-length digital images of the sections, and to measure their color and magnetic properties. The photo above shows my fellow night shift sedimentologists, Benny Reinardy and Ruthie Halberstadt, at work in the sedimentology lab.

Both in the X-rays and in the split core we find layers that include rocks and minerals that were dropped from ancient icebergs as they melted. Icebergs are made of pieces of land ice that have broken off glaciers in the ocean. Even though these icebergs may have melted millions of years ago, the rocks and minerals are the scientific evidence of the iceberg’s existence in the past and can be used to trace the paths of icebergs in the ocean currents. The rocks dropped from icebergs (ice-rafted debris or IRD) in the layers we describe provide us with one way to gain knowledge about the past environment and climate in the Amundsen Sea. Some layers contain ice-rafted debris and some don’t. The X-ray image shows a picture of density changes. Rocks “floating” in the mud are hard and dense and they show up as dark blobs, whereas the mud around it is soft and less dense. The X-rays travel through the soft mud, but not as well as through the dense rocks. It is the same when you take an X-ray of an arm or leg with a broken bone: the bone is denser than the tissue and the X-rays make it visible.

We also keep track of evidence of ancient life embedded in the layers. The food chain in the Antarctic Ocean is quite special. We have seen humpback whales around the ship, which feed on krill. In turn the krill feed on microscopic plants called diatoms. Even today diatoms are at the bottom of the food chain here in the Southern Ocean. Depending on the environmental and climate conditions in the past diatoms were blooming here in the Amundsen Sea or not. Also, different types of diatoms do well in different environments. We found the type of fossil diatom above in several of our smear slides samples from the core. Its name is Eucampia antarctica, it looks like a fancy letter “C” and it likes cold polar ocean environments. However, other diatoms don’t like to live in the cold at all and the paleontologists have found fossils of these types of diatoms as well.

Core on deck!

The Joides Resolution is drilling in more than 4 km of deep water in the Amundsen Sea and we are surrounded by icebergs every day. This provides for some beautiful scenery, but it is not always good for drilling if they are coming straight at us! Several times over the past few days we have had to pull out of the hole with the drillstring, and move the ship out of the way of a passing iceberg, and we are now in our third hole at the same site. The good news is: we have recovered beautiful complete cores going back in time several millions of years including through prominent warm periods. These archives of the ice-sheet’s history will allow us to retell the story of how the West Antarctic Ice Sheet behaved in the past under warmer conditions.

After some foggy days, which were really difficult for the ice watchers, the weather has cleared and the ice watchers can better track the movement of icebergs. The ice watchers, which include the captain and his crew, use three different ways to make sure an iceberg is not impacting the ship. First, they use satellite images to map the track of large icebergs. However, smaller icebergs are not visible at the scale of the satellite images they use. So, for smaller icebergs down to a size of approximately 5 m across and more than 1 m high, the shipboard radar is used. Individual icebergs are numbered and their tracks are mapped on the radar. Lastly, icebergs that are less than 1 m high above the sea and less than 5 m across, so-called growlers and bergy bits, are difficult to observe on the radar. These smaller icebergs are spotted by eye from the bridge. The smaller icebergs have been causing us the most trouble in the fog, but now that it has cleared we are back on track.

Cores come up in 10-m long segments every few hours ("Core on deck!" on all speakers). In the photo you can see the 10-m long tube with sediment (the core) being carried onto the catwalk by the core technicians. On the catwalk the core is cut into 1.5 m long sections so that it can fit through the shipboard labs. The sediments are hard now, and core sections are being split in two halves with a motor saw, whereas previously the soft mud could be cut with a wire. After piston coring for more than 200 m down into the sea floor, we are about to change over to the XCB rotary coring system to drill farther down into the rock and to uncover the early history of the Amundsen Sea’s ice behavior.