Images of the Day
Antarctic Discovery - Reaching Antarctica's Subglacial Waters
WISSARDs Tristy Vick-Majors and Alex Michaud are the featured speakers at the Colorado Springs Science Festival, Tuesday October 8th at Colorado College, in Colorado Springs, Colorado. With ground penetrating radar, scientists in Antarctica have discovered that under the massive ice sheets is a vast hydrological system of liquid water – existing from geothermal heat flow from below. After decades of planning, the first successful retrieval of clean, whole samples from an Antarctic sub glacial lake took place this January. The Whillans Ice Stream Sub glacial Access Research Drilling (WISSARD) project used a hot-water drill to melt through 800 meters of ice to access the sub glacial Lake Whillans. This international team of scientists found river basins carrying microorganisms and nutrients to the Southern Ocean. Using this window to peer into the sub glacial world, this team explored one of our planet’s final frontiers to answer the question, “what lives underneath Antarctic ice?”
If you are in the area, join the fun!!
WISSARD will explore the grounding zone during the 2013-2014 season
A map of the Whillans grounding zone region showing surface topography (contours) from high-resolution GPS measurements. Colored lines show ice thickness values along ~ 650 km of ice-penetrating radar profiles done by the WISSARD ground-based geophysics group in 2011-12. Grayscale background is the surface topography derived from MODIS satellite imagery.
Our focus for 2013-2014 season is the grounding zone, an area where the Ross Ice Shelf of the Antarctic Ice Sheet starts to flow from land to ocean and float as the Ross Ice Shelf. WISSARD scientists will explore the ice, ocean, sediment, and microbial life found in this area. Scientists consider grounding zones as critical areas to learn more about so we can improve our capability to make better predictions about the behavior of ice sheets. Our ability to make more accurate models becomes even more important as our climate warms.
Microbial life in Subglacial Lake Whillans
Bacterial colonies formed on solid nutrient media that was spread with Subglacial Lake Whillans water samples. Scientists are in the process of identifying what these slow growing bugs are--stay tuned as we learn more in the coming months. Testing and analysis of Lake Whillans sediments and waters are underway in many of the participating research facilities. This image is from the Christner Lab Group at Louisiana State University.
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).
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.