Most of the science group has been working in 4 hour shifts thus far - 4 hours of work and then 8 hours of time for other things each 12 hour period. The last day or two, I was using my 8 hour rest periods to eat a couple of saltines, lie down, and attempt to ignore the rocking of the ship, but I must be getting used to the seas (and they are calmer!) because I can now do other things like read papers and look at a computer screen.
We have been collecting data almost since we left port. We are mapping the bathymetry, collecting gravity data, recording ocean current directions, etc. Since we entered our 3-D box area yesterday, it's been exciting to identify fault scarps in the bathymetry.
Donna mentioned in her previous post that once a streamer is in the water, its location is monitored and it can be moved around using winged devices called "birds" that are attached to it. Imagine a number of actual birds holding a cable in their talons at an even spacing while flying. Our mechanical birds are not so different, except they are flying the streamer through the water. We can see where the birds are on a computer screen in the lab, and we can control the depths of the birds by remotely moving their wings. When a streamer goes into the water, it can take some time to get the weighting right and then for the birds to dive the streamer down to the desired depth (generally 8-12 meters below the sea surface).
3rd June (posted late due to internet outage)
Assembing a bird to be attached to the streamer.Birds for streamers 2 and 3 waiting to be deployed.
After steaming for twelve hours out of port, we started the long process of putting out all of the seismic gear needed for this program. The weather worsened as we headed towards the field area, and we have been deploying equipment in 3-4 meter swells for the last 18 hours. This ship can roll by up to 10-15 degrees in these conditions (and more than a couple of people are feeling sea sick as a result). On the deck, ropes and cables connected to equipment towed off the back of the ship lurch and clank rhythmically, and water commonly washes over the lower deck. Down in the main lab, stray items that aren’t properly stowed or strapped down start to roll back and forth, the ship creaks and groans, and office chairs swivel with each swell.
For this program, we will be towing an enormous amount of gear behind the ship to enable us to image faults involved in rifting, the exposure of mantle rocks and continental breakup in 3D. Four 6-km-long seismic ‘streamers’ filled with pressure sensors (which can detect returning sound waves) will be towed 200 m apart, for a full spread of 600 meters. As we deploy the streamers, we add weights to ballast the streamer, acoustic units to determine the locations of the streamers, and ‘birds’ that enable us to control the depth of the streamer remotely. We also swap out broken pieces. The streamers are held apart by two gigantic paravanes, which are like large metal kites that fly out from either side of the ship. Each one weighs an astonishing 7.2 tons and is ~7.5x6 meters in size. There are also myriad floats, cables and ropes to maintain the correct geometry of the entire array. The streamers will record returning sound waves generated by two arrays of air guns, which will be towed 100 m apart and fired separately. We expect that it will take us 3 days to deploy this complicated array of equipment behind the ship. The weather is expected to start improving tomorrow afternoon, which will help us greatly!
2nd June Looking forward on the Langseth as she takes a roll in the swell.A streamer with a 'bird' being deployed off the Langseth's stern into the waves.
The R/V Marcus G. Langseth pushed away from the docks of Vigo at 8 am local time. The sun was shining, and the views of the rugged cliffs, forests and Galician towns along the coastline were spectacular. We will only be able to see land at the very beginning and very end of this 45-day cruise. We steamed out of the protected waters around Vigo and out into the open Atlantic Ocean a few hours later, and happily were met by relatively calm seas (1-2 meter swells), although its quite brisk compared to summer weather back home. We actually saw the F.S. Poseidon in the distance as she headed back to Vigo at the end of the first OBS cruise of this program. We only have a relatively short transit of ~10 hours before we begin to deploy the extensive suite of scientific equipment behind the ship needed to image the structures beneath the seafloor in 3D. Putting out the seismic streamers and associated gear will take 3 days!
1st June The science party on deck as the ship departs Vigo.
I returned to New York on Monday, but Lamont-Doherty Earth Observatory scientists Andy Juhl and Craig Aumack remain working in Barrow, Alaska for another week. They’ll continue to collect data and samples in a race against deteriorating Arctic sea ice conditions as the onset of summer causes the ice to thin and break up. Even in the two weeks I stayed in Barrow the ice changed dramatically, shifting from a snow-covered ice pack to a nearly snow-free ice pack, covered in cracks and increasingly large melt ponds. An animation from the May 23 Barrow sea ice radar reveals just how quickly shorefast sea ice can change. Soon the ice will be deemed unsafe for travel by snow machine and spring fieldwork conducted on the ice will end.
Our team’s research in Barrow is just one part in the long process of studying and answering questions about algae growing in and under Arctic sea ice and its role in the marine ecosystem. And, it’s a process that does not necessarily have a defined end — investigating the natural world always leads to more questions. From fieldwork, where observations are made and data gathered, new questions arise, new hypotheses are put forward and new ways of collecting data are developed. This work leads to further experiments where new data and samples are collected, observations are made, analyses performed and results interpreted. Some of the findings will challenge existing hypotheses, leading to their modification, which starts the research process over again.
Fieldwork gives scientists the opportunity to observe systems in a holistic way, leading to new insight and further research questions; each piece of data causes a rethinking of ideas and expectations for future results. “Fieldwork is inspiring and it’s critical to the creative process for environmental science because you often see things that you don’t necessarily see in your data,” said Andy. “There are subtleties and patterns that you can pick on if you pay attention to observe the natural world. You can’t do that in the lab or by looking at numbers.”
Some people may be disappointed to learn that we don’t have many immediate answers about sea ice algae and the Arctic ecosystem based on our month of Barrow fieldwork. But, scientists don’t set out to study things that are already understood or to answer questions that already have answers, and it takes time to unravel Earth’s mysteries. On this trip, project scientists discovered and collected lots of algae, observed novel behavior by marine organisms in the water column and on the seafloor, and gathered lots of data. The next steps in this project are to analyze the samples and data collected in Barrow, interpret these, write up findings and report these in journals and at scientific meetings. And, in 2014, Andy and Craig will return to Barrow to continue their study of sea ice algae, armed with new understanding of the algae, as well as new research questions to explore.
The goal of our project is to understand how ice algae functions and its role in the marine ecosystem, but we’ve received many questions about how ice algae, the residents of Barrow and the rest of life in the Arctic will be affected by a climate that is undoubtedly and irrevocably changing. The answer is that we don’t know, but our research may contribute to future understanding of these issues. Though the Arctic is changing faster than anywhere else on the planet, with temperature increasing and ice volume decreasing, it is still one of the least explored places on Earth. In order to know how climate change will impact this region, the basic oceanographic and ecological processes must first be understood.
As our project progresses, we’ll continue to provide updates and look forward to sharing a video of our time in Barrow that’s being produced by our friends at Climate Science TV. For more information on this research project, visit http://lifeintheice.wordpress.com. Our colleagues at Lamont-Doherty Earth Observatory also travel the world exploring our planet; to keep up with more interesting Earth science research and reports from the field, follow Lamont-Doherty on Twitter and Facebook.
And thanks to everyone who followed our expedition, we enjoyed sharing it with you!
Today they are reloading the ship with 18 more OBS to deploy on Leg 2. The personnel on board will also exchange two Ocean Bottom Instrument Consortium personnel for two GEOMAR personnel.
What is an OBS?
An OBS is an autonomous instrument that sits on the ocean floor and records waves (sound waves as well as other types) traveling through the earth and/or ocean water. All of our Galicia instruments have ocean bottom hydrophones (OBH) to record waves traveling through the ocean (including some types of whale calls!), and a subset of fifty also have geophones to record waves traveling through the sediments and rocks beneath the sea floor.
The OBS record waves by measuring tiny motions of the earth and sea water, converting it into electrical signals, which are stored digitally. The geophones, data logger, and batteries are stored in a water tight, floating sphere, and the hydrophone is attached to the outside of the sphere. A heavy anchor attached to the sphere enables it to sink to the bottom when it is deployed (sent off into the ocean).
To pick up the OBS, the ship goes to the location where it was deployed, and a sound signal with a particular frequency is sent out. The OBS replies acoustically, cuts its anchor, and resurfaces. Scientists can then download the data and begin to piece together a picture of the local Earth structure!
It’s near midnight and Lamont-Doherty Earth Observatory researchers Andy Juhl and Craig Aumack, and Arizona State’s Kyle Kinzler are gathered around a table in their lab at the Barrow Arctic Research Consortium discussing the best way to catch an isopod. When scientists do fieldwork, they enter into it with specific questions and science goals in mind, but one of the joys of exploring the world through scientific research is solving challenges and devising new ways to collect data.
Meet Brinson. He’s a remotely operated vehicle (ROV) along on our Arctic expedition and named in honor of a foundation that provided Andy funding to build him. Brinson, originally designed and built by engineer Bob Martin, and modified by Andy, is the result of an idea that evolved over several years of Arctic fieldwork.
“We were deploying just this ice fishing camera, but were frustrated by the fact that there was always something just beyond our range that we wanted to see,” said Andy. “So we wanted mobility and once we got that we were frustrated by the fact that we didn’t know how big things were, and that’s when we decided we needed the laser pointers to provide scale. So Brinson has been a multi-step evolution into a simple, but well-equipped ROV.”
Brinson now consists of a GoPro camera and a standard ice fishing camera attached to a frame made of PVC pipe that can be lowered into a hole in the ice. On the ice surface, the ice fishing camera’s live video feed shows what Brinson sees as he travels through the water. Brinson is equipped with small bilge pumps that act as motors, which enable him to be maneuvered forward, up, down and side to side via his tethered remote control. When Brinson is below the ice, Craig monitors the video feed and describes to Andy what he sees on the screen. When something of interest appears, Craig tells Andy which way to maneuver Brinson, so they can continue to get footage of the organism.
Brinson recently saw small crustaceans called isopods roaming around the ocean floor. Andy and Craig were excited about this find and very curious to learn more about what isopods might eat and their role may be in Arctic the marine food web. Once Brinson, and Andy and Craig, saw the isopods, it was decided that our team should catch some, but we had no trap or means of doing so.
Scientists need to bring absolutely everything they need, and think they might need, with them on research expeditions, especially those to remote areas like Alaska’s North Slope. So, when, for example, you decide you must build an isopod trap late at night in Barrow, you’re pretty much limited to what you have on hand: a plastic buckets, plastic window screening, electrical tape, rocks, string.
With these materials, a little ingenuity and their limited knowledge of isopod behavior, Craig and Kyle constructed isopod traps. The guys hypothesized that isopods might like chicken, so baited their traps with chicken bones saved from our dinner. The traps were attached to eight meters of string and dropped to the sea floor. Kyle’s trap sat overnight and caught two isopods; Craig’s trap sat on the ocean bottom for several days and contained at least 20 isopods when it was pulled up.
The beauty of the isopod traps is that they worked and project scientists will get valuable data about the Arctic marine food web as a result. “From the underwater videos shot by Brinson, it looks like the activity of the isopods increases after the ice algae exports,” Andy explained. “We think there’s a plausible connection there: the ice algae could be a food source for isopods. We never would have posed that as a hypothesis unless we had the opportunity to observe them and make these connections.”
Fieldwork is, in part, a pattern of observing and questioning, and responding to these with new theories, methods and experiments. It’s also part of a larger creative process that involves improvisation and unconventional thinking. Said Andy, “In the field, we make a lot of stuff out of duct tape and epoxy.”
We dropped 17 ocean bottom seismometers today, making 26 in all. The weather is cloudy but bright. There is 2-3 m of swell and this is not a very big ship, so when we were steaming eastwards into the weather there was plenty of water arriving on deck. Later on we turned to the west, which was more comfortable and drier. Scientist cabins are partially below the water-line and my port-hole gets a regular wash.
24th May 2013
Seventy-two OBS will be deployed in a grid of 18 x 4 instruments across the 3-D seismic survey box. Six OBS will be deployed on a profile extending farther west, to try to locate the boundary between continental and oceanic crust.
An OBS is deployed. Photo by Dean Wilson.Gaye Bayrakci, a postdoctoral researcher at the University of Southampton, sent this email update today:
"Yesterday (23/05/2013) the weather was ok. We tested 24 acoustic units first. Then, we deployed 9 OBSs along the regional profile. Before the finish of the day, we tested 24 more acoustic units. Food is good. Thursday is the seaman's day, so we had some cake at 5pm at the coffee break.
"Today (24/05/2013) the weather is darker but its normal for this period of the year in this area. We started at 06am (utm). We just finished the deployment of 8 OBSs on the southernmost profile and reach the eastern end of regional profile. We deployed a 9th OBS here and now we are heading westward along the regional profile."
The international team of scientists aboard the Poseidon includes two GEOMAR geophysicists, two University of Southampton geophysicists, and five OBIC personnel from University of Southampton and Durham University.
The internet connection on board the Poseidon is not good enough at the moment to post to this blog or send photos, so the above photo is from a separate OBS deployment in the Indian Ocean.
Stay tuned for more updates soon!
24th May 2013
One of the goals of Andy Juhl’s and Craig Aumack’s Arctic research is to determine the role of ice algae as a source of nutrition for food webs existing in the water column and at the bottom of the Arctic ocean. During their fieldwork these Lamont-Doherty Earth Observatory scientists are deploying a plankton net, a common tool used by ocean scientists to catch tiny marine plants and animals in the water column, to collect live plankton for identification and examination in the lab. They’re hoping to determine the different kinds of organisms active in this part of the Arctic Ocean and their food web feeding connections, or who’s eating whom by testing the organisms to see if they contain algae in their guts and muscle tissues.
This information is important because it will provide a baseline understanding of the connection between the algal community in the sea ice and the underlying ecosystem, and how it functions. Once this is understood, scientists may be able to better understand and predict changes that could occur in the marine food web as Arctic snow and ice cover changes.
A few days ago we caught the comb jellies in this video near shore at a depth of about four meters. Though comb jellies have the same type of gelatinous body as a jellyfish, they belong to a completely different phylum called ctenophores. Known for being vicious carnivorous predators, ctenophores use rows of comb-like cilia to propel themselves through the top of the water column and prey on smaller organisms, such as zooplankton. Ctenophores are found throughout the world’s oceans, including Arctic waters — quite a few of appeared in the holes we’ve bored into the ice this week.
These two comb jellies were filmed under a microscope in our lab. Each one is just a few millimeters long, though they can grow to be about 10 cm, sometimes larger. You can also see small copepods, a type of zooplankton and favorite food of ctenophores, zipping around the screen. Seeing a lot of ctenophores in the upper water column is a good indicator that they are feeding extensively on copepod larvae, who in turn are feeding on ice algae. This is an example of a few of the connections that make up the foundation of the food web in this fragile, yet biologically productive ecosystem.
On Wednesday Andy and Craig answered responded to questions about their research during a Reddit “Ask Me Anything” session. While the event is over, the session remains on Reddit and we encourage you to check it out to learn about our research and life in Barrow, Alaska.
Our team spent most of Friday on the Arctic sea ice, drilling and sampling ice cores at our main field site. For each core collected, Lamont-Doherty Earth Observatory scientists Andy Juhl and Craig Aumack take a number of different physical, chemical and biological measurements that characterize the ice and the organisms living inside it. Some of these measurements are recorded right away in the field, others will be taken later using pieces of the cores that we bring back to the lab.
Two of the physical measurements Andy and Craig record are the temperature and salinity of the ice. “Temperature is a critical parameter that controls the rate of almost all biological processes in the ice — almost everything happens slower when it’s colder, and parts of the ice can be colder than others. And if you know the temperature and the bulk salinity of the ice you can calculate how much brine volume there is within a given layer in the ice,” Andy explained.
Brine volume is an important measurement because algae live in brine channels in the ice. As ice gets colder, there’s less brine volume within it, meaning there’s less room for algae to grow. Andy and Craig also measure the concentrations of plant nutrients in the ice cores, including nitrate, ammonia, phosphate and silicate – some of the same elements that plants growing on land need. And, as with terrestrial plants, nutrient availability in sea ice is a factor that controls the growth of algae inside the ice.
Other measurements, such as particulate organic carbon (POC) and dissolved organic carbon (DOC), Andy and Craig take in the lab will reveal the amount of carbon, or organic material in the ice. In addition to algae, carbon found in the ice comes in the form of non-living materials, such as bits of organic detritus from the tundra that become trapped in the ice. Finally, samples are collected for microscope work so that project scientists can identify the different types of organisms found throughout the ice.
All of this information varies in any single ice core from the top to the bottom, and based on where it is drilled. By taking consistent measurements from each ice core in different locations, project scientists can develop an in-depth understanding of the dynamics of the Arctic algal ice ecosystem – and how it may be changing.
Our group spent Saturday and Sunday in the lab processing samples from last week and preparing equipment, including mounting a camera system on our small remotely operated vehicle (ROV). We’re heading back onto the ice early Monday morning with the ROV and are looking forward to working in temperatures that may reach 35F.