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Picking forams on a rolling ship One of the most delicate parts of our job at sea happens at the microscope—something that sounds routine, until the ocean decides otherwise. Out here, we’ve been collecting tiny marine organisms called foraminifera—single-celled protists that build shells (called tests)—from the surface of seafloor sediments. While microscopic, these organisms are incredibly important in paleoceanographic research, as their shells preserve information about past ocean conditions. In the upper layers of the cores we recover, foraminifera are not just buried in the mud, they also often cluster on hard materials like rocks, sponges, bryozoans, and other seafloor debris. These tiny specialists seem to prefer something solid to latch onto—living right at the sediment–water interface, where the bottom of the ocean meets the overlying water column. Seasick scopes and foggy views After retrieving these hard substrates from the top few centimeters of each core, we bring them to the microscope for picking. But picking forams at sea presents challenges you might not expect. Even when the waves aren’t dramatic, the motion of the ship is amplified in the microscope, causing the image to sway and bounce. Looking into the scope under these conditions can quickly bring on seasickness—especially when the ship is pitching enough to send all the swivel chairs rotating around the lab. We learned early on that picking sessions have to be timed carefully. If the ocean is too rough or a storm system is passing through, it’s better to wait. We’ve even had to tie down the microscope with line and metal braces to keep it steady on the table. Everything in the lab has to be secured, including our trays, vials, and tools—one rogue wave and you risk losing hours of work. We originally struggled with an awkward scope setup that we endured for hours each day, but after so long at sea some rearranging was required and we now have a much more ergonomic space. We also use special picking trays with narrow grooves, which help stabilize the sample as we carefully tease apart the materials and extract the tiny foraminifera. And while most days a thick fog blankets the view outside, the microscope reveals a whole hidden landscape of life clinging to fragments of the seafloor. Tiny victories Despite the motion, the fog, and the challenge of working at sea, we’ve had great success. So far, we’ve filled nearly 100 cryovials with foraminifera and have several more stations to go! These samples will allow us to explore foraminiferal communities at the sediment surface, complementing the geochemical and micropaleontological studies focused on the deeper parts of the cores. Pairing foraminiferal ecology with geochemical profiles collected by collaborating teams on this expedition will help build a more detailed and dynamic picture of ocean change—linking what lives on the seafloor today to past environmental conditions. We may not see much of Greenland’s dramatic coastline past the fog, but each core we recover brings the seafloor right to our fingertips. There’s something exhilarating about that first look—even after 40 multicore recoveries, it never gets old. And when that material goes under the microscope, that sense of wonder only grows. For me, it’s a chance to see an entire hidden world, magnified. AuthorAshley Burkett Lately, it has been super busy as we had back-to-back stations with lots of science operations running round the clock. Now that we have wrapped up our operations in the Labrador shelf and have also completed our station in the center of the Labrador Sea, our next series of stations will be close to Greenland and inside some of the Greenland Fjords. Over the last few weeks, the ship has become our home. During this time, we also experienced things that are quite unique, and today’s blog is about a few of them. Also, please enjoy a video of pilot whales below! Foghorn! It is not uncommon to have dense fog in the middle of the ocean. The fog reduces visibility and therefore the ship needs to use sound to warn other nearby vessels of its presence and to avoid collision. So, this is like a car horn in some respect. However, there is a lot more to it than just letting other vessels know of its presence. For example, a small vessel will have a higher-frequency foghorn sound, and a larger vessel will have a lower-frequency sound. So, another vessel in the vicinity that cannot see us would not only know about the presence of another vessel but would know about the size too. These are the technical aspects of the foghorn, now let’s talk about our experience of trying to sleep with the foghorn, which is blown every two minutes. Boy, it is loud!! Some of us scientists are in rooms that are close to the foghorn by the bridge (from where the captain and mates drive the boat), and the foghorn has been a revelation. The foghorn rattles the walls every time it blows, and it goes on as long as there is fog around (which can be for days). After a day or so, we got used to the rhythmic blowing of the horn and then it stopped as the fog cleared. Now the absence of the foghorn is difficult to bear. Survey sound As part of our work, we use sound to survey the ocean bottom. These instruments produce periodic sound pulses, which travel to the bottom of the ocean and come back to a receiver on the boat. The two-way time of sound allows us to estimate the depth at a point. We do this over and over and when all of these depths are put together, we can create a map of the ocean floor. One of these sound sources (3.5 kilohertz) can also penetrate a little bit into the ocean bottom, allowing us to gauge what type of materials are at the bottom. We heavily depend on this type of survey to decide where to collect sediment versus when to move on. Scientists whose living quarters (called state rooms) are close to these sound sources hear periodic ‘chirps’ as we survey along. Time changes Since we left Woods Hole, we have had three time changes. The last two time changes were within one week. We are currently three hours ahead of the US eastern time. Every time there is an impending time change, the crew would put signs all around the vessel and come change the clocks. All time changes happen at night and as a result the night shift worked one hour less, and the day shift had one less hour of sleep. Sorry, day shift! AuthorChandranath Basak We have been transiting for last several days and we are about to reach our next station. Things are going to be busy real fast. We encountered a little choppy weather here and there, so at times we had to slow down. Many of us saw our first iceberg, which was extremely exciting. During this long transit, we have been talking to a lot of students from a range of classrooms on shore. So far we have connected with thousands of students - elementary, middle-school and high-school - in the USA and Switzerland (find resources for educators here). It has been super fun to see people interested in the work we are doing and we are equally happy to show them around the ship and explain what we are doing. Students submitted a range of questions that our scientists have answered - see the FAQ below! How does your research help with climate change?
One of the ways we understand how our climate is changing is by looking at changes in climate throughout Earth's history. We do this by using something called "proxies" - a chemical measurement we can make in the modern day that reflects some geologic process in the past! Neodymium (Nd) is one of the key focuses of this research cruise and is often used as a proxy for water masses and ocean circulation throughout Earth's history. But we can only use proxies like Nd to reconstruct that past if we understand how these elements behave in the ocean: where do they come from, are they removed, and what other processes might impact them?
We use our understanding of how different Earth processes relate to each other to inform the models we use to project changes in our climate. By studying the past, we can better understand our present and what we think might happen in the future. How do you collect and analyze water samples from thousands of meters deep?
Some of the deepest water we're collecting on this cruise is 3600 m deep (that's about the length of 33 American Football fields)! At that depth, we can't swim down and simply collect the seawater in a bottle.
We use a special instrument called a CTD (which stands for Conductivity, Temperature, and Depth) that measures the salinity and temperature of the water. We lower it on a wire and get readings sent back to the ship. Attached to this instrument are 24 special bottles called Niskin Bottles, which are open as we send the CTD down. Sending the CTD to 3600 m can take over an hour! Once we have a profile of what the salinity and temperature is like, we decide which depths we want to sample seawater from. Then, we bring the CTD back up to each of those depths and "fire" the bottle to close it. Once all the bottles have been closed, we bring the CTD onto the deck of the ship and the scientists collect samples of the water depths they want to study. How do you use sediment to learn about what the ocean was like thousands of years ago?
There are multiple ways we can look at sediment to learn about what the ocean was like thousands of years ago, but on this cruise, we have people looking at microfossils within the sediment. These are super tiny creatures the size of a grain of sand called foraminifera that either live in the sediment (called benthic foraminifera) or live in the water column (planktonic foraminifera). These creatures build a shell out of a material called calcium carbonate, which is the same material seashells and coral are made of. They build these shells by taking calcium and carbonate dissolved in seawater and combine them into a hard shell. But while they build these shells, other elements dissolved in seawater (like magnesium or lithium) can enter the shell structure. Changes in the seawater can affect how much of these other elements enter the shell.
When these creatures die, they get buried in the sediment. Then, scientists can look at the chemistry of the foraminifera shells across thousands-of-years’ worth of sediment layers to learn about those changes the seawater chemistry. How do you make sure your samples aren't contaminated?
We are studying trace amounts of metals (like iron) in a big metal ship! Fortunately, there are ways to make sure our samples don't get contaminated. One of the ways we do this is by making something called a "clean bubble" on the ship. We put up plastic sheets to make a tent like room and filter the air that is pumped into the space. We affectionately call it "The Bubble" because it looks like a bubble in the middle of the main lab.
Anyone who works in The Bubble must change their shoes to special clean Crocs and wear clean clothes that won't shed fibers into the samples. We make sure to clean our sampling equipment with super clean water before using it and we store all our samples in pre-cleaned containers to ship back to our labs on land for analysis. Have you ever encountered any dangerous situations at sea?
One of the challenges of doing research at sea is making sure the ship, crew, and scientists are all safe. The Captain has been working with the crew and scientists to make sure we avoid situations that could be dangerous (such as extreme weather or sea ice). Things like sea ice can sometime interfere with our ability to collect samples, so we must stay flexible as the expedition progresses. But safety is a top priority!
To make sure we're ready for any possible situation, we do safety drills about once a week, so we know what to do and where to go in case of an emergency. Since we're in the North Atlantic, we're keeping a close eye on both stormy weather and sea ice, and making sure everyone on the ship feels prepared for any possible situation. Thanks to all the scientists who helped organize and run these ship-to-shore sessions. We had fun during those sessions and I hope everybody who joined had fun too. We are about to reach our next station, so have to keep this short today. More to come, so stay tuned. AuthorChandranath Basak As I write this blog, we are leaving Station 1. Most of us have had only a few hours of sleep in the last 24 hours but we know we are ready for what is coming. Station 1 was intense and full of surprises and taught us how we should run our operations. In a research cruise, the first station is always very stressful and a bit chaotic, as scientists try to get all types of samples they want and at the same time try to find a rhythm so that things go smoothly. So, it becomes a bit difficult. Lucky for us, the weather was great, so we had one less challenge. Here is a quick summary of what happened at Station 1. One of the main goals of the expedition is to collect short cores from the ocean bottom. To do that, we need to make sure that our target locations have soft sediment. If we land our coring gear on a rock, it will simply break our equipment, which we absolutely want to avoid. So, about three nautical miles before we reached our Station 1, we started surveying the ocean bottom to locate soft sediments (lovingly called ‘mud’) so that we can deploy our coring device. The survey started a little after midnight, and we found the right kind of mud around 3 a.m. We also wanted to collect water samples at different depths, so we put out a series of bottles and some sensors first. As these sensors are lowered, they send real-time temperature, salinity, and pressure data to us. This helps us decide where to collect our water samples. This operation took about 4–5 hours, and then we deployed the ‘Multicore,’ which is the main coring device for this expedition. This device has 8 empty tubes. The top of the tubes is capped, and the bottoms are open. Once it reaches the bottom, we let the whole device sink into the soft mud, and as it is pulled out, there are contraptions that close the open end at the bottom and hold the mud. This time we also had a camera installed on the Multicore so that we could see what the ocean bottom looks like. The Multicore operation is complicated, but we have experts who have extensive experience in running these operations, which we are heavily relying on. The deployment was successful — the Multicore went down to a depth of 3,500 m (over 2 miles), penetrated the sediments successfully, and then, as it was time to pull it out of the mud, we lost camera feed on one of the cameras. For the next couple of hours, as the Multicore was being pulled up through the water column, we did not know what went wrong, and if we would get any sediment in the coring tubes. The whole science team was on deck, waiting to see what happened as the Multicore was being pulled out of the water. MIRACLE! The contraptions that close the tube bottoms and hold the mud had broken off on most tubes, yet the suction from the top cap was still holding the mud in the tube. Seems like the keepers of the ocean really want us to have mud. There were a lot of smiling faces as we did retrieve sediments, but also a lot of worried faces as the Multicore needed quite a bit of repair. We wanted to do another Multicore deployment at that location, but it was clear that it would take several hours to repair it. In these situations, scientists must decide whether they want to wait or rather conserve the time and move on. Since we could retrieve the most urgent samples from that one deployment, we decided to move on to the next station — which is three days away. AuthorChandranath Basak Since our last post, a lot has happened. Most of the science party has reported to the ship, and we’ve been moving all the science gear (which we worked so hard to clean, pack, and ship) onto the vessel. There are multiple science objectives to be investigated during this expedition, and each one requires something unique to be done in a specific way. For example, one project needs an extremely clean environment to handle its samples. So, the scientists have been busy building a clean bubble with specialized air filters attached, ensuring the air inside contains as little dust as possible. They’ll be wearing special shoes and gloves, and avoiding fleece—since it tends to shed fibers. Another project will be collecting particles from the air as the ship travels. For this, we installed a dust-collecting device on one of the top decks (which has an amazing view). There are many more similar operations we needed to sort out before leaving port. By and large, things have been coming along well, and we are ready to set sail. Bon voyage to us! AuthorChandranath Basak |
