by Dr. Robert A. Bindschadler
PIG through PRISM's eyes. This is a 400m x 400m area of the surface of the Pine Island Glacier from one of the PRISM images. The grooves running up and down are sagging "snow bridges" covering deep crevasses. The black areas are holes where the snow bridges have collapsed revealing open voids in the ice. This is a dangerous place, but typical of the areas we hope to land a helicopter so we can measure ice shelf thickness and water depth beneath the ice.
High- Resolution Image 807x801 pixels, 176KB
We know now that we’ll just have to sit this next season out. It’s a reprieve for Tim who is working hard on the new ocean instrumentation. It will have to perform the first time. Once it is lowered into the water beneath the ice shelf, there won’t be any chance of pulling the instrument package back up through the hole—the hole will begin to freeze shut the moment the drilling hose comes out making it a rush just to get the instrument down the hole while it still fits. Tim will use his extra time to make additional tests, increasing the likelihood that his part of the project will be successful.
Meanwhile, my time is split between sifting through new images of the ice shelf and working with a contractor planning our field support for the 2009-10 season. The imagery piece is more fun. We are going to be using data from a Japanese sensor called PRISM that photographs the surface with 2.5 meter resolution. This lets us see amazing detail of the surface and proved extremely useful when we planned and executed our aerial reconnaissance last season. Fortunately, the controllers of this satellite sensor took a lot more shots of the ice shelf the past year and we were lucky enough that many had clear views of the surface. We’ll have to piece together about 6 images to capture the whole ice shelf, but it will be a valuable way of planning where our drilling camp should go and where we might be able to set down a helicopter to get the 30-or-so spot readings of ice thickness and water depth elsewhere on the ice shelf.
Planning the field support is a new experience for me in a number of ways. I’m used to working from small tent camps. Larger camps with semi-permanent buildings and maintained snow runways with dedicated camp managers, mechanics and cooks were just waystations for me. Now my camp is the “big kahunah”--the two helos will need special landing pads and large fuel bladders, and the pilots require berthing and meals. There will be lots of LC-130 “Herc” flights to bring in the helos, fuel and people. And for every Herc that flies the full 1400 miles to PIG, another Herc flight is needed to cache fuel at another camp partway, to allow the long-range Herc to refuel so it can return to McMurdo. In a flash, we exploded from a small drilling camp to a 6-building small town! I’m stressing the need to keep things as small as possible, but the minimum requirements already vastly exceed my Antarctic “footprint” from past seasons. It’s taking some getting used to.
...or those of you who are interested in how our continuing observations are going, the weather last Sunday on PIG was minus 18 degrees Celcius, the wind (always directed down the glacier) was blowing 24 knots and 40 centimeters of snow have collected since January.
by Dr. Robert A. Bindschadler
You can view the latest blogs by going to the Earth Discovery Live Website (this link will move you outside of the NASA site).
This project has a number of new wrinkles in it for me. One is that through the entire process of deciding on what to propose, writing the proposal, and then rewriting the proposal after the initial rejection, I never met some of my co-investigators. Honestly there never was a crying need for it because our many team teleconferences and scores of e-mails allowed us to communicate effectively. Still it felt odd that I could pass them on the street and not recognize them.
That was corrected last month when ALL the PIG investigators met (well not absolutely everyone—only one of the four British collaborators was able to get across the Atlantic, but I know all of them very well). David Holland, my field buddy now freshly shaven and all cleaned up, hosted at the meeting at New York University. We sat in a rather unremarkable city-university building in mid-town New York City discussing a very remote part of Antarctica. David was an excellent host, inviting us to his apartment for a pizza dinner the night before our meeting making it nicer to finally meet all my collaborators socially.
The meeting had a rocky start. Our program manager, who has fought so hard for our field project, had to tell us that both money and major logistic equipment (like airplane hours) are so tight that we would not be able to go the field next season. Earlier conversations I had had with the group strongly hinted at this, so the news didn’t break our spirit. We also knew that we only had one day to plan our next steps and it would do little good to whine or complain.
So we set to our tasks. David and I updated the group on our findings from our reconnaissance trip and everybody else gave a quick summary of where their contribution stood. Most important was the discussion about what we would need in the field to accomplish the drilling, the deployment of the videocamera and ocean profilers and the seismic and radar survey. The program manager had to keep reeling us in as we succumbed to the temptation to do more than we had proposed. Key additional people at the meeting were some of the contract planners who would be translating our desires into specific dates, weights and numbers of flights.
The details would probably bore you, but I was very impressed with how well everybody stayed “on task”. We used the whole day, all the blackboard space and probably a few megabytes of computer disks to lay it all out, arrange and rearrange the dates and tasks, but by the end, we had a workable plan—at least in our eyes. Getting back to the PIG ice shelf, setting up a helicopter camp nearby, checking out possible drilling sites, deciding, moving 12,00 pounds of gear and people there, drilling a hole and deploying cameras and ocean equipment (and, don’t forget getting back to McMurdo!) will take a full two months. Now we have to refine the plan. Unfortunately, we have lots of time to do this. Fall of 2009 seems sooooo far away—and the measurement we plan are sooooo urgently needed.