The past week has been full of quintessential Antarctic experiences. I want to highlight these in the blog today because I actually spend a lot of time in the lab rather than outside on deck, so these experiences have been very special.
1. Penguins: we got up close to a pair of Emperor penguins the other day as a large piece of sea ice floated by. They stood by watching the boat, craning their necks every so often like they were trying to get a better look at the giant, orange thing in front of them. My favorite thing about Emperor penguins is how they walk: it’s a slow shuffle as they move an entire side of their body in one motion. By contrast, I always see the little Adelie penguins run in spurts. They usually hold their wings out behind them and run so far forward it looks like they are going to trip over their little feet.
2. Blizzards: Antarctic storms are world-renowned as ferocious white-outs with howling winds and temperatures many tens of degrees below 0°C. We have hit a few storms throughout our cruise, but a couple days ago, we stepped out on deck to flying snow that stung our faces and temperatures so cold we could only stand to be outside for a few minutes. Some sea ice was piled higher than the back deck and I couldn’t see more than about 50 yards in any direction. This particular storm was located north of the ship, but it had pushed much of the sea ice south toward us. We are still trying to break through into open water. It’s slow going, but the captain and mates are working hard to get us through and ship speed should pick up soon. Continue reading
Chief Scientist and Chief Rock
The past 48 hours (approximately) have been relatively calm as far as work goes since some bad weather (35-45 knot winds) has halted over-the-deck operations. However, we were able to maintain station long enough (3.5 hours) for a rosette CTD and Amelia’s water pumping, which allows her and her colleagues at USF and elsewhere to collect archaea in different water masses and compare their population genomics. The 48 hours before these last two shifts (and I mean the full 48 hours) were packed with core sampling and collection. So as Michelle recently blogged, those days when we all count sleep as our “fun activity” of the day definitely come after these busy, but incredibly rewarding and exciting days and nights.
Good coring weather
When the night-shifters woke up on the 21st, we saw two 3-meter kasten cores open on the table, being sampled simultaneously by the sizeable group of day-shifters. They had already taken Amelia’s DNA samples, foraminfera and organic geochemistry samples via syringes, and almost completed the diatom sampling for Amy. They had also brought up our biggest JPC to date: 13 meters! All of these cores were taken at the same station, which had a lot of interesting diatom-rich layers that we were able to see in the open kasten cores and via the magnetic susceptibility in the JPC that we ran on the 22nd. The day-shifters were still wide awake and active when we came to relieve them, and we were excited to dive in to these new samples. Continue reading
I have never been affected by island fever. When I was going to school in Hawaii, people used to ask me, “Don’t you get island fever?” when I got back from a semester at UH-Hilo. “No, although sometimes I do get Hilo fever,” I would respond, referring to the fact that it was hard for me to get out of Hilo due to school, work, and no car. I understand why people would feel trapped on an island but it just never phased me.
What could be more fun than recovering Eocene/Oligocene boundary rocks?
I think about that question now that I have been on a ship for close to a month. I guess one would call it Palmer Fever. And the answer is “No, I don’t get Palmer Fever.” I think the reason is we stay busy everyday. The last two days have been up-on-your-feet-for-12-hours kind of days. By the end, everyone is pretty exhausted. However, there are slow days and we have free time when we come off shift. So what do we do? We have found fun and quirky ways to keep busy, on and off shift.
While passing time on a slow shift, most people read, write papers, or help another group with their sampling. Occasionally, someone will post a crossword and passers-by will stop to fill out a word or phrase on their way between jobs. For the students, downtime during shift is a perfect time to write a blog, check email, or peruse papers that our PIs have assigned.
During our time off, there are a surprising number of activities to keep a person busy:
Game Face status: on
The natural evolution of the Seasickness Competition
- Sleeping: we are usually falling over by 3AM after a noon to midnight shift (for the day shifters). This counts as fun for a bunch of students.
- Cornhole tournament: there has been a fair amount of smack-talk and off-hours practicing as people are starting to get competitive.
- Movie night: each night after a day shift, a couple of the ship’s mates host a movie in the lounge, which they call Action Theater. Action Theater usually involves comedies/action flicks and high-tech Nerf guns.
- Working out: In addition to individual workouts, we have a sign up sheet for pushups/sit ups. Every time an instrument goes into or comes out of the water, you have to do however many pushups/sit ups you signed up for. I signed up for 10 push ups, so if a core is deployed I have to do 20: 10 for in the water, 10 for out of the water. I think I have done about 450 pushups, with about 100 to catch up on.
- Galley socializing: On a busy day, like today, dinner is a short affair. However, after shift is done, a group will often spend 45 minutes in the galley just hanging out and chatting.
We also love to celebrate: Continue reading
When you think about Antarctica, what first comes to mind? I’ve had quite a few people ask me about penguins and polar bears when I first told them I was traveling to Antarctica. Truth be told, polar bears only roam around the Arctic, and penguins only frolic here in the south. The penguins find company with the seals and whales that also live in the Antarctic, or sometimes become dinner for them. These guys are the token mascots for every image that most people conjure of Antarctica. They are also heavily protected under the Marine Mammal Protection Act so part of our job when we conduct science is to ensure our science minimally impacts wildlife.
Adelie penguins in “flight”
We worry most about our impact on marine wildlife when we conduct seismic surveys. The seismic guns deliver a low energy pulse into the water column, which may have the potential to negatively affect marine mammals if they are exposed to 180 decibels or more in the water. For that reason we have two qualified marine mammal observers, Andrea Walters and me, on-board to ensure we do not injure wildlife during our seismic gun operations. Our science party must also conduct marine mammal observations (MMO) when the ship is breaking ice in order to record how many marine mammals we might be exposing to our operations and to record how icebreaking may alter their behaviors. Icebreaking potentially produces quite a racket that can expose animals within 12 nautical miles to 120 decibels underwater. MMO during icebreaking is a new practice so the data we record will be extremely helpful in understanding how icebreaking impacts the animals. Continue reading
As Michelle’s most recent blog stated, our past couple shifts have been hectic while we processed our first five cores. The jumbo piston core (JPC) and jumbo gravity core (JGC) were both 20-foot long barrels, each returning approximately 10 feet of sediment excluding the 1-foot trigger core associated with the JPC. The JGC is similar to the kasten core in that it is allowed to “free-spool” on the winch as it nears the ocean floor during its descent and then uses its own weight to penetrate the sediment.
Dan Powers checks the bomb as we prepare to deploy the JPC
The JPC is rigged a little differently, with a counter-weight (the aforementioned short trigger core) suspended below a triggering mechanism that holds the main JPC barrel, the weight (known as “the bomb”), and a coil of slack line. When the trigger core hits bottom, the main JPC barrel is released and free-falls the remaining distance into the sea floor. This method generates more momentum than free-spooling a core on the winch line, thereby increasing the depth to which the core may penetrate. The coring system on the Palmer can support JPCs up to approximately 25 meters long, but other vessels have successfully deployed JPCs that recovered as much as 80 meters of sediment!
The piston that gives the JPC its name ends up at the sediment-water interface if the core is successful and is designed to improve recovery. The way this works is analogous to putting a drinking straw into a glass of water and covering the top of the straw with your finger to take water out of the glass using suction. Even though our cores have been relatively short so far, recovery has generally been good. The recovered sediment is contained in the 4-inch diameter PVC liner that fits in the JPC barrel. When the core is retrieved, we extrude the liner and cut it into 10-foot sections.
Unfortunately, we have to patiently wait to do most of the processing on these cores because if we cut them open now, we won’t be able to securely ship them to the USAP core repository in Florida State University for final processing. Therefore, the only sediment we get to see on-board now is the sediment in the cutter nose and core fingers (the very bottom of the core), the sediment between the sections of PVC liner we cut, and whatever mud is on the coring device. Continue reading
(and the Grease, and the Salt Water)
The past week has been a busy one. We have secured 3 full kasten cores, 1 jumbo gravity core and 1 jumbo piston core (with 1 accompanying trigger core). A kasten core has a rectangular barrel that is deployed via gravity. It penetrates 2-3 meters into the sediment and can be opened on the ship so we can describe the stratigraphy, take photos, and collect samples. Each kasten core takes about 12 hours to process, depending on the length. First Gene has to describe the core (color, layers, sediment composition), then Tasha will take pictures. After that, someone on shift puts on the lab coat and nitrile gloves and takes samples for DNA/RNA.
The next round of sampling includes taking sediment for organic geochemical analysis and foraminifer microfossils (fossils of calcareous single-celled animals). These samples will be used for a suite of geochemical analyses to determine past temperature, productivity, and oxygen content, among other things. While geochem and foram sampling are happening on one side of the core, another person is sampling for physical properties on the other side. If there is enough mud left, we will also take pea-size samples for diatom analysis and 5-cm interval samples for radiocarbon. Believe it or not, the first layer of sampling on a 2-3 m core takes 7-8 hours with planning, putting together the core barrel, sampling, cleaning sponges and utensils, labeling bags, and sample storage/inventory. These are the days when the marine geology group spends 12 hours on their feet. Continue reading
Kelsey and Gene rocking out
We started for the Totten Glacier area, our main study area, at around 11:45am GMT on Wednesday, February 7th. Our shift on Thursday the 8th began with processing the dredges, starting with our most recent dredge that targeted the Eocene-Oligocene boundary for the second time (importance of that temporal boundary is discussed below). First, we cleaned each rock individually from small pebble to boulder size. We arranged them on a table in the dry lab into the three rock categories (igneous, sedimentary, and metamorphic) and then roughly subcategorized those groups. Once the rocks were dried and laid out on the table, Gene helped us finalize our sorting, and discussed what we found. The sedimentary rocks are the most important because they can tell us about past depositional environments. After we finalized our categories, we counted, photographed, and packaged the samples (1,029 total!). This took us about 9 hours to complete, leaving four dredges left to process (with each dredge having 7 to 394 total samples, which all went a lot quicker!)
Sunrise on the back deck
That same day, we had a science talk regarding our dredging and seismic results, along with overall Cenozoic climate change trends. Amelia discussed the trend of overall cooling that we have seen over the Cenozoic. This was determined using oxygen-18 isotope records, establishing an ice volume record throughout the Cenozoic. In 2000, magnesium-calcium paleothermometry was used to isolate sea water temperatures from the ice volume record, showing a 12°C overall cooling since the Mesozoic. From these curves, clear climate transitions were shown at the Eocene/Oligocene boundary (~34 million years ago), the Middle Miocene (~14 Ma), and the Pliocene/Pleistocene boundary (~5 Ma). It is still being debated what is causing this cooling, but two current hypotheses are 1) ocean heat transport due to the opening and closing of oceanic gateways and 2) overall decreasing atmospheric CO2 due to changes in seafloor spreading, uplift, and weathering. Continue reading