Images of the Day
Planning Begins in Earnest for the 2013-2014 Season
Logistics for the upcoming WISSARD season are being discussed this week, when an all PI meeting convenes at the Antarctic Support Contract offices in Denver, Colorado on April 10th, 2013. Detailed field planning will take place. In the meanwhile, water and sediment samples continue to arrive and are being processed at institutions across the country. The WISSARD Education and Outreach team are working on creating WISSARD scientists of the future, and are presenting some WISSARD science at NSTA, the National Science Teachers Association National Conference, Friday, April 12th, in San Antonio Texas.
Last of the WISSARD science team northbound
The samples have all been packed for shipment, preliminary analyses completed, labs and offices cleaned up and gear returned. The last four WISSARD science team members are ready to fly home. In order to leave McMurdo Station on a US Air Force cargo aircraft your baggage must be taken to the Movement Control Center the evening before the flight. Everything, including the person and their handcarry bags, are weighed so the air crew know exactly how much weight the plane will be carrying. The checked bags are then strapped onto a pallet in preparation for loading the aircraft. Carefully planning what is in your handcarry bag is important, because the flights are frequently delayed by weather or other circumstances, and the clothes and personal items in it are the only things you can access for the day or more you may have to wait.
Return traverse daily progress - 11 Feb 2013
The return traverse made 68 miles yesterday, with good weather and some chores to do at the WISSARD fuel cache. Officially, by crossing the dateline (180 degrees longitude) they have to give back the day they took on the outbound, but of course, operationally WISSARD SLW stayed on the same time as McMurdo/New Zealand.
WISSARD traverse return journey 8 Feb 2013
The SPoT2/WISSARD traverse is on their way back to McMurdo Station. The green line shows their progress after a day and a half of travel, they are one tenth of the way back. We hope they have a safe and smooth journey back, which has been timed to avoid the impending winter weather.
The First View of the Bottom of Subglacial Lake Whillans
The first view of the bottom of Subglacial Lake Whillans - soft lake sediments crumble as the WISSARD underwater camera touches the bottom. The area viewed in the image is about 0.15 meters (6 inches) across (credit: Dr. Alberto Behar, JPL/ASU; underwater camera funded by NSF and NASA).
Borehole Operations
Four days of 24-hour borehole operations were carried out at the WISSARD site at Subglacial Lake Whillans. Both water and sediment samples were collected from the lake.
Water sampling tools deployed included a niskin water sampler, which allows you to collect water samples at designated depths, an in situ McLane water sampler that concentrates water particulates on filters, and a CTD which measures Conductivity, Temperature and water Depth.
Three different sediment sampling tools were used including a multi-corer, which collected 3 ~40 cm cores each time it was deployed, a piston corer, and a larger percussion corer. For more information about our sampling tools, check out the Science Instrumentation section of the WISSARD webpage.
Image: Chief Scientist, Dr. John Priscu deploying instruments into the borehole.
Deploying a borehole video camera
Real time video was very useful for inspecting the shape and size of the borehole, as well as peering through the lower borehole opening into the lake. The "mothership" camera was deployed on it's fiber optic and kevlar tether using a capstan winch for a controlled descent. Tyvek suits are used by operators on the deck to minimize any manmade contaminants; the tether ran through a UV germicidal collar just prior to entering the borehole, which is off to the left of the picture.
Another Good Day at the WISSARD Site
Good news from the WISSARD Field Camp!! Sensors on the hot water drill show a water pressure change, indicating that the borehole has connected with the lake. Verification awaits visual images from a down-borehole camera this evening. We are excited about the latest developments at the lake!
Drilling into Lake Whillans
The WISSARD team was thrilled when the traverse made it to the geographical location of Subglacial Lake Whillans on January 13th, 2013. The traverse crew, scientists, and drill team have been working in earnest, and the WISSARD project is getting close to reaching another milestone—actually reaching the lake itself—800m below the surface of the ice. Drilling operations have been ongoing for the past couple of days, and the drill team is in the final stages of drilling today, January 26th, 2013. To prepare for accessing the lake, the team changed nozzles to a wider spray (rather than concentrated jet used to make the borehole). The drill team will then drill the last 100 meters and break through more gently into the lake itself, making a wide/funnel shape in the bottom of the hole to avoid gushing drill water into the hole and stirring up sediments.
The team also did some work widening the hole at 100-110 meters, so they can make sure that the main borehole is well connected to the "keyhole" that contains the water-return pump. This way they can do a good job of controlling the depth/height of water in the borehole - (they want slightly less water pressure in the borehole than in the lake when they break in, so that a little lake water will come into the hole, vs. dumping drill water into the lake).
Today they are getting back down to the 700 meter mark, and will melt through to ~750 m. They will drill more slowly for the last 50 meters and should be through the ice (i.e. to Subglacial Lake Whillans) within 8 to 10 hours, baring no difficulties.
Image: Irina Alekhina. Head Driller Dennis Duling with the hose and drill nozzle at the test site in December 2012.
WISSARDS Reach Subglacial Lake Whillans
The WISSARD traverse team successfully reached the surface of Subglacial Lake Whillans the evening of January 13th after a historic trek of 628 miles across the Ross Ice Shelf. This is the next step as scientists begin their push to study one of the final frontiers on Earth, the subglacial Antarctic environment. The Whillans Ice Stream Subglacial Access Research Drilling (WISSARD ) project is a multidisciplinary scientific initiative focused on the aquatic ecosystem that lies beneath the Whillans Ice Stream.
Research is being conducted through integration of complementary science projects focused on Subglacial Lake Whillans (SLW), one of 300+ lakes buried below 800 meters (2,625 feet) of ice.
Scientists are interested in two research areas.
The first is the role of subglacial lakes in stabilizing or destabilizing the West Antarctic Ice Sheet—data collected from this project will be used to improve modeling of ice sheet dynamics. Samples of subglacial sediments and basal ice will provide an opportunity to study the history and evolution of Antarctic subglacial lakes and the ice sheet itself.
The second area involves looking for microbial life in the lake. The search for life in subglacial lakes is on the leading edge of scientific discovery, and is currently being pursed through three international efforts, including the American effort at Subglacial Lake Whillans.
Understanding the biodiversity hypothesized to be in the lake will provide fundamental information about microbial life that exists in dark and cold conditions, provide a measure of the limits of life on Earth and other icy worlds, and yield a better understanding of biochemical processes involved with elemental transformations on our planet.
WISSARD Geophysics in the Deep Field
Our traverse is making good progress toward Subglacial Lake Whillans, and our first wave of scientists heading to the deep field begins tomorrow! The WISSARD deep field geophysical team is traveling toward the lake first via a ski equipped LC-130 Hercules, and then onward via skidoo's to service and maintain 23 GPS stations which are used to measure vertical and horizontal ice movement on the Whillans Ice Stream. You can see the 23 stations in relation to Subglacial Lake Whillans in the map above, created by Matt Siegfried.
Matt Siegfried, one of the scientists on the geophysics team from Scripps has a fantastic blog where you can learn more: http://scrippsonice.wordpress.com/. We'll share more of this interesting project this week as the team begins their work on the ice... Travel safe Slawek, Matt, Grace, JT and Doug! See you at SLW!
Heading South...
The typical traverse set-up is 8 tractors and one Ground Penetrating Radar vehicle, which leads the way and checks for crevasses. The WISSARD traverse has 12 tractors and 1 GPR vehicle. Each tractor can pull up to 100,000 lbs on the steel skids. Fuel Badders (top left, in the image) weigh as much as 220,000 lbs. The WISSARD traverse is carrying 36,000 gallons of fuel, and should burn 24,000 to get to Subglacial Lake Whillans--using 40 gallons per mile to pull the heavy loads.
Image by Peyton Adkins