As we transit west from the outer shelf to the inner shelf of the Larsen A, we have been stopping approximately every 10 nautical miles to collect CTD’s, Yoyo camera footage, and kasten cores. The night watch has been sampling kasten cores nearly constantly for the last few days, but had not had the opportunity to actually collect a core until early this morning. As the sun was rising, we took a CTD from a mid-shelf location, and immediately after were briefed for deck safety during core collection. We successfully deployed the mechanism with the help of our marine techs, Julie and Buzz, and extracted a 1.5 meter core, KC-12. After working on cores in the sediments lab back at Hamilton and sampling in the dry lab on the Palmer, it was satisfying to finally see how the cores are collected. We cleaned the core and brought it inside as the early morning light and the Seal Nunataks rose around us, our first glimpse of land in nearly a week. Our shift ended with cleaning the core to prepare it for description and scans. After, during our daily science meeting, we received exciting news; while the sea ice conditions in the Larsen B are still perilous, by Monday, a storm is meant to roll in. We hope the winds from the storm will make for more favorable ice conditions and perhaps provide an opening to our ultimate destination.
We’ve seen a flurry of activity over the past couple days as we began to sample at our first station. ‘Station 8’ is located on the mid-continental shelf and will be used as a control as we transit closer to the coastline where the Larsen A and B ice shelves used to be. It is far enough away from the mainland that we expect to see less influence glacial activity on the modern seafloor. However, we’ve done three Kasten cores, which can sample up to six meters below the seafloor, providing a longer term history of the ice. Cores are of particular interest to geologists, because, in some ways, you can read a core like a book. With the help of Jeffrey Evans, our onboard sedimentologist, I could piece together a picture of the environmental changes that have taken place over time.
Because LARISSA is an interdisciplinary project, we all pitch in as often as teams need help. I was lucky enough to have an opportunity to go ‘ashore’ to work on the sea ice. Primary productivity occurs in the sea ice as well as in the open water, so the biologists need to measure the contribution from both.
Firmly encased in a bright orange full-body floatation suit, I was lifted over the side of the boat with the other members of the party. Our goal was to collect six ice cores to determine algal distribution, temperature, nutrient, and heavy metal concentration through the ice’s stratigraphy. While coring the ice, I could only wonder at the other-worldly oddness of standing on an ice flow. The ice is at least nine feet thick, but I could see the ocean only thirty feet away in one direction (near the boat), and at least 200 feet in the next. And the snow-covered float was an irregular, surface with strange wind sculptures that were at least a couple feet taller than I. And to top it off, three penguins snuck up behind me as I was digging into the snow. Jeremy Lucke, a Marine Technician, came up and started taking pictures of (I thought) my impeccable digging form.
“Turn around very slowly,” he said.
The penguins, only six feet away, barely startled when I squeaked and dropped my shovel.
The fact that there are always graduate students from other institutions participating in these Antarctic research expeditions is one of the key benefits for Hamilton undergrads. They have the opportunity to observe and learn from their older peers and to experience the type of projects in which they might be engaged should they, too, decide to pursue a graduate degree. It is rare that undergraduate students from any institution travel to Antarctica. This is an experience usually only available to graduate students.
Hamilton alumna Liz Bucceri ’11 was invited by Associate Professor of Biology Michael McCormick to join this expedition because a portion of the research they are undertaking on the trip is a continuation of her thesis completed last year. She had worked with Professor McCormick’s samples taken from the last LARISSA cruise. Liz, who is considering a couple possible graduate study programs, described the opportunity as “a great experience to meet a lot of great scientists and [engage in] real research sampling. I am also learning a ton about Antarctica and the amazing research taking place here…. the experience is once in a lifetime.”
In this blog below, Liz describes the work undertaken by Duke PhD candidate Megumi Shimizu, another member of Professor McCormick's team, who is working with her and Hamilton junior Andrew Seraichick:
Professor McCormick's research team consists of four researchers: Professor McCormick, Andrew Seraichick ’13, myself and Megumi Shimizu. Megumi is a PhD student at Duke University, currently a second-year student in a five-year program. She studies at the Duke Marine Lab, specifically in the marine science and conservation program.
During this cruise to Antarctica, she is helping with the marine microbiology sampling, but she is also doing some of her own sampling. For her doctorate, she is investigating the lipid levels of microbes in the Antarctic sediments. Specifically she is interested in the interactions between the lipid levels and environmental changes as well as the chemical components of the sediment.
With the Antarctic sediments, she wants to focus on how the retreating of major ice shelves has affected microbial lipid levels. One of the plans of the cruise is to get various samples from different horizons from the retreating of the Larsen B Ice Shelf. Each horizon will represent a different time period in the ice movement with sediment and water open from beneath ice for varying time periods. Megumi plans to take sediment samples from these different horizons and hopes to see how the microbial lipid levels have changed across them. This cross-link of microbiology and geology is something that interests her very much and is something she hopes to pursue in her program as well as after she receives her doctorate.
This Larissa cruise is her first major research cruise, but she has been on several day-cruises to Cape Lookout Bight, N.C. During these trips she collected marine coastal sediments in order to do similar lipid microbial research. She says that this expedition to Antarctica is much more exciting both from a scientific standpoint and a traveler's standpoint.
Before Duke University, Megumi spent four years in Toyko, Japan, earning her undergraduate degree. She was born in Osaka, Japan, but spent most of her life in Kyushu, which is located in the western part of the country. She has spent the last two years in Beaumont, N.C. When she has finished her PhD, she is uncertain whether she will stay in the United States or return to Japan. Ideally she would like to spend time in a completely different place, doing research for a few years before settling down. After this trip, she will have traveled to every continent except Africa.
Two days ago several of us went on an expedition to Roberston Island on the Antarctic Peninsula. The biology team's goal was to find and sample sediments from a possible fumarole (a volcanic geothermal vent) at the site of one of the GPS stations on the island. In 2010, Professors Gene Domack and Amy Leventer set up this station and observed several areas of steam escaping from the rock debris as well as the smell of sulfur, both of which could indicate an active vent site. We set out to the island after breakfast with the goal of finding these sites and taking some temperature readings as well as collecting rock debris samples for DNA and gas analyses.
The trip was awe-inspiring as it was the first time for almost all of us to set foot on an Antarctic island. Our group hiked up to the top of the plateau on which the GPS station was located and began our search. Unfortunately, we saw no evidence of gases escaping. We tried to find the vents by taking temperature measurements in the rock debris in the area, but to no avail. We gave up hope of finding the vents and began a basic visual survey for any other samples that we could analyze. However, we were forced to head back to the boats soon after we began our survey because the tide was coming in and would have stranded us on the island for several hours.
After our unlucky expedition to Robertson Island, we were glad to start research yesterday on a research station at the outer edge of the Larsen A area. We took samples from the ocean floor by means of a megacore array, 12 individual cores on a frame that takes a 30-centimeter core out of the sediment. The megacore was very successful with only one core not working correctly, so we were able to take three cores for analysis, our optimum number.
Once we got the cores, we wrapped them in specially made mylar blankets and stored them in a cold room at zero degrees Celsius until we could sample them. We began by analyzing our first core using microprobes, taking several measurements including oxygen percentages and pH in increments of a centimeter or less. Once we finish with our microprobing, another scientist will take our core for viral DNA samples, and we will begin sectioning and sampling our second core for geochemical characteristics such as alkalinity and nutrients.
By the time we finish with this station, our group will be sampling seven more megacores as well as a much larger Kasten core. The atmosphere on board is very excited now that every group has lots of work from this station. There is very little down time, and sleep is becoming an extremely precious thing to all of us.
65 13.13 S
59 23.56 W
Today was an especially exciting day for the Hamilton crew of geologists and biologists who were part of a field party sent ashore to nearby Robertson Island. When we heard that stepping on land was a possibility for today, Natalie and I worked with Colgate Professor Amy Leventer, Colgate student Kara Vadman, and University of Alaska student, Jason Theis to pack for the trip. Jeff Evans of Loughborough University (UK) and Caroline Lavoie (Canada) were also along to map the marine limit along Robertson Island’s shoreline.
We distributed the following supplies between the five members of the geology field group:
Needless to say, we brought large backpacks aboard the Zodiac pontoon boats that transported us to the island. Our goal was a relatively simple one: to collect pieces of the igneous rock, granite, from glacially-deposited boulders strewn around the island. The samples will be analyzed at Lamont-Doherty Earth Observatory in New York, and the quartz within the granite will be dated using a technique called “cosmogenic exposure dating.” We know that the granite boulders were deposited by ice, and the theory behind the dating method assumes that once the massive ice sheet retreats, it leaves behind newly-exposed boulders, resetting the rocks’ “internal clock.” The dating method allows us to determine an approximate time limit on the boulder’s exposure. Analysis of samples collected today will allow us to determine a timeline for ice sheet retreat on the island after the last glacial maximum about 11,000 years ago.
While we photographed the samples, annotated our field notebooks and hammered off a few pieces of granite from the boulders, we were also able to admire our stark surroundings. Brown windswept hills topped by loose angular siltstones and gravel made it easy to believe that we were standing on one of the world’s deserts. The blue of the iceberg-filled ocean contrasted dramatically with our barren surroundings, providing a dazzling backdrop for our task. The Palmer looked miniscule for the first time against the endless landscape. And even though the wind chill made the area seem entirely inhospitable, we were greeted by buckets of bright green seaweed that had been collected by the biologists during their time in the field.