The following is a satellite image of Alice Orlich’s and Adrienne Tivy’s cruise track on the Louis S. St-Laurent. The dates are midnight UTC. From left to right, the red dots are at Tuktoyaktuk, Kugluktuk, Cambridge Bay (Adrienne Tivy disembarked there), and Resolute (small dot at 7/17). Alice Orlich is still on board. The MODIS image West of Kugluktuk is from 23 July, whereas the MODIS image East of Kugluktuk is from 19 July. Greenland is the white area in the upper right corner. The Beaufort Sea is in the area in upper left side.
The following are assorted photos from the East Siberian Arctic Shelf Expedition 2011.
Here is a general view of the FEBRAS-IARC camp built up for the drilling campaign accomplished from the fast ice in the Laptev Sea. Scientific and technical personal included 20 people. It includes two two-store baloks (mobile houses including living space and labs), heavy caterpiller, the drilling rig URB-4T mounted on second caterpiller, three heated tents (lab space), two cargo-slages with fuel and drilling equipment. The total cargo weight delivered by ILUSHIN-76 was about 30 tonns.
~ Natalia Shakhova and Igor Semiletov
The Arctic region contains a huge amount of organic carbon, referred to commonly as the “Arctic Carbon Hyper Pool,” within the Arctic Ocean sedimentary basin. The Russian Arctic shelf acts as an estuary of the Great Siberian Rivers. This area has the highest documented rates of coastal sedimentation with annual accumulation rates of about 10×106 t Corg year-, which approximately equals the amount of sediment accumulated over the entire pelagic zone of the World Ocean. Due to the specific features of sedimentation and lithogenesis in this area, much of this organic carbon survives decomposition, and is buried within seabed sediments. These sediments are annually (“offshore” permafrost) or seasonally frozen, representing a substantial reservoir of potentially labile organic carbon. Global warming in the Arctic region is predicted to be substantial, and possibly rapid, in next few decades. Upon permafrost melting, the old carbon stored therein will be reintroduced into the modern carbon biogeochemical cycle, possibly acting as a strong source of methane to the overlying water and potentially the atmosphere. Additionally, extremely large amounts of more ancient (Pleistocene) methane are trapped as gas hydrates within and beneath the permafrost.
The proposed work aims to elucidate the present and future methane flux potential of sediments and permafrost in regions of the East Siberian Arctic Shelf. As a result of global warming, seafloor permafrost along the East Siberian Arctic Shelf may experience a pronounced change in thermal regime. Increased temperature may affect permafrost in several ways, ultimately leading to its degradation and enhanced CH4 release. This international, interdisciplinary research team will determine the distribution and stability of permafrost on the East Siberian Arctic Shelf and evaluate this area as a methane source to the Arctic region.
Cores from eleven locations will be obtained using dry drilling techniques. Rates of biological methane production and consumption (oxidation) will be quantified in permafrost and sediments at in situ and elevated temperatures. Natural abundance stable carbon (13C and 14C) and hydrogen isotope measurements will be used to quantify the age and source of methane collected from different sites and depths. These data will be used as input to numerical models, which will be developed to describe the thermodynamic and biogeochemical aspects of permafrost methane dynamics. Using field data and modeling, the current and future potential release of methane from offshore permafrost will be determined and a methane budget for the East Siberian Arctic Shelf will be constructed.
~ Natalia Shakhova and Igor Semiletov
IARC ice observers have found themselves rather busy over the last couple of days, as they were able to access ice floes two days in a row to conduct sampling.
The first visit, on the 7th, was a substantial operation involving the deployment of multiple buoys. A floe of considerable size and thickness was needed to accommodate the equipment and the 14 crew members assembled to assist in the undertaking. This proved difficult, as the ship was traveling in a vast expanse of young grey ice, with only an occasional intrusion of cake-size floes of multi-year, or second-year ice. Luckily, as the recon helicopter was making it’s way back to the ship, a suitable floe was found. The large group descended onto the floe late in the afternoon, and worked as quickly as possible given the task at hand, time restriction due to dwindling daylight hours, and cold temperatures.
IARC ice observers were able to drill at 10m intervals along a 100m line, for an ice thickness measurement survey. The line ran perpendicular to the buoy operations, and traversed over several small ridges. Depths ranged from 37cm to 354cm. Several large pockets were found near the middle of the line, approximately 25-35 cm down, indicating a rafting of at least two ice floes or blocks. Thinner ice measurements further down the line towards the floe edge revealed newly formed ice. Two core samples were taken at the beginning and end of the line. The sample at 0m measured 207cm, and the sample at 100m measured 44cm. Production on the later, however, was interrupted by an abrupt call back to the ship. The traditional core temperatures at 10cm intervals were taken, and then the core processing was completed aboard the ship.
Ice operations on the 8th were considerably different. On this day, only one buoy was in need of deployment, and while a sizeable piece of multi-year ice was preferred, it was not a necessity. Ultimately, a small cake size floe was chosen. Due to the size of the floe, IARC observers did not lay a transect line, but decided to concentrate their efforts on taking ice core samples instead. Three cores were taken; an 83cm core came from rafted multi-year ice, a 22cm core was pulled out of this season’s grey-white ice, and the final 156cm core shared the same area of the floe as where the WHOI ITP#44 was deployed. It should be noted that the first core hole was actually greater than 83cm, but an unusually hard surface prevented the ice auger from penetrating beyond approximately 250cm. The situation was perplexing, as the gear, including the corer’s cutting bits, the power source and all connections in between had been in proper working order. The measurements signaled to the ice observers that this floe was rafted multi-year ice with a void between the surface layer and the resilient lower floe/block beneath.
The past two ice visits concludes on-ice work scheduled for cruise participants this year. The remaining days at sea will now focus on retrieving and redeploying another WHOI mooring (BGOS-D), and continued water sampling near the Banks Island shelf break or within the Canada Basin, as time permits.
~ Alice Orlich and Heidi Isernhagen
IARC ice observers had a long, productive day on the ice yesterday. As the WHOI crew and Mike Dempsey arranged for the deployment of three buoys (ITP #42, IMB, and the Arctic Flux), the IARC group along with a variety of magnificent volunteers were able to set out two transect lines, as well as take ice core samples. An initial 100m line was set up along the length of the floe, producing surprising results almost immediately. The first hole drilled revealed an ice thickness of only 25cm! The subsequent holes showed a modest growth in thickness with an interesting occurrence at the 30m mark; a significant void was discovered in the ice, followed by another layer of ice, indicating an area where two ice sheets had rafted together.
An additional perpendicular 70m line was laid out to transect this area, revealing measurements ranging from 29 cm to 185. Voids in the ice occurred at several intervals along the ice. Kazu Tateyama and Kohei Mizobata were able to run their EM-31 along both lines (as well as two additional lines), to gain ice thickness measurements using electro-magnetic induction. Results of these tests have yet to be released for comparison to the IARC data. Ice core samples were taken at the 0 meter mark of both transect lines. The salinity measurements will be conducted aboard the Louis after the samples melt.
We are proud to announce that all on-ice operations ran smoothly, and the entire group (14 people!) was able to accomplish all relevant tasks and leave the floe shortly before a thick fog rolled in. IARC personnel would like to express gratitude to the fabulous volunteers Sarah Zimmerman, Chelsea Stanley, Zoe Sandwith, Kelly Young, and Michiyo Kawai who contributed to the collection of data while conducting themselves in a safe and professional manner.
~ Alice Orlich and Heidi Isernhagen
Unexpectedly, yet gratefully, the IARC crew was able to access the ice pack for a few hours late Saturday afternoon. A small (~100m) multi-year floe near grey ice was selected for the WHOI crew to redeploy their ITP (now named ITP #41). This occurred in an area of medium and large floes of multi-year and second-year ice. The IARC crew was able to use the allotted time to run a small transect line (50m) in the center of the floe, averaging an ice thickness of 371cm. This time on the ice provided an excellent opportunity for the new student observer to get a hands-on feel for the equipment and methods involved in sampling the ice pack.
More ice time is scheduled for the 4th and 5th of October as multiple buoy deployments will afford extended time on the ice. To add to the excitement of the day, two polar bears were spotted as the ship moved toward the ITP site, and a spectator from the bridge noticed a seal in the water as the Louis was parked and waiting for the deployment operations to conclude.
New ice continues to thicken as grey ice in the area measures between 15 – 30cm, assembling in medium and large floes. Alice Orlich noted vast sheets of new ice from her vantage point aboard the helicopter during a recon excursion earlier in the day.
~ Alice Orlich and Heidi Isernhagen
IARC student Heidi Isernhagen stands in the early evening light near the ice thickness survey line set up on a small multi-year floe. The orange flags are positioned at the beginning, end and along the 50-meter transect at 10-meter increments, where thickness measurements were made with the 2" auger.
Room enough for all: The ship's helicopter is parked near the ITP deployment site while the WHOI team and a few deck crew work to set the system in the ice floe. In the distance, IARC student Alice Orlich stands at the end of the ice thickness survey transect as reference to the orientation of the floe activities.
Job well done! Heidi and Alice celebrate their first success as a field research team. Today's flawless test-drive of the equipment, Heidi's first on-ice experience and their newly forged work dynamic is reflected in the afterglow of the workday.
Vertical relief! A helicopter reconnaissance is a welcome escape from the vantage point of the ship, and can allow for pleasant discoveries. In an area dominated by young level ice, this old multi-year floe rumpled with steep, heavy ridging was well defined in the rare clear sky.
Smooth sailing ahead: This flight was sent up to chart a course that could be the path of least resistance for tomorrow's navigation plan. Vast areas of new ice stretched to cover the ocean to the horizon.
Optical illusions at 900'. Curious textures abound in this image captured through the helicopter window. New ice of various age and thicknesses display smooth, white rafted nilas, wispy grease and frazil patches, while dark grey nilas with fresh frost flowers suggest a tawny hue as the low sunlight illuminates the icy prisms. A jagged matrix of long, thin finger rafting demonstrates the dynamic movement within the thickening pack.
So near, but so far away! Just when you think all the luck is on your side, plans can change. After nearly 2 hours in the air with clear skies and brilliant ice view to document, the helicopter was requested to wait out on the ice while the buoy recovery. As the minutes ticked by, the temporary castaways made the best of the bright sun and -30C temp. Activities such as photography, pacing the floe, enjoying a smoke break, dancing, or the occasional athletic feat, such as Alice's lifting of the ship, were some means to occupy the passing of time. (credit: Erick Thibault)
As the CCGS Louis S. St. Laurent headed northwest (from 75°N 149°W to 78°N 152°W) towards the second WHOI mooring, observers on board noted the beginning of a budding ice pack with sheets of nilas thickening to produce young grey ice in varying concentrations and thicknesses. Among the burgeoning ice pack, cake size floes of both multi-year and second-year ice abound, forming a total ice concentration ranging from 80% to 90%.
The retrieval of the mooring went smoothly thanks to the ship’s remarkable ability to cut through ice and keep it at bay with a bubbler system, as well as the hard work of the deck crew. We will be returning to redeploy the mooring in a couple of days. In the meantime, we will be heading further northwest to locate one of the WHOI ITPs (ice tethered profilers) that had ceased transmitting some time ago, and then inexplicably began communicating again recently. Deployment of an ITP provides opportunity for the IARC team to gain access to the ice pack, allowing for ice thickness transects and ice core samples to be acquired.
To learn more about the Woods Hole Oceanographic Institution’s operations and other science projects being conducted on this cruise, follow their blog at www.whoi.edu/beaufortgyre/dispatch2010/index2010.html.
~ Alice Orlich and Heidi Isernhagen
A new generation of ice: Various forms of nilas begin to cover the open water in the discontinuous icepack. In the foreground, pancake-sized nilas join into a sturdy sheet that meets another sheet of level nilas that stretches to the horizon. Notice the nearly symmetrical finger rafting pattern that transects the photo across the center.
