Pine Island Glacier 2011: It’s Showtime!December 9th, 2011 by Maria-Jose Viñas
By Bob Bindschadler
Greenbelt (MD), 23 November — After years of waiting, our time has finally come. The years have not been empty. There have been hundreds of e-mails, scores of telephone conferences and a handful of face-to-face meetings to iron out the mountain of details required to support more than a dozen scientists’ intent of unlocking critical mysteries within the light-less, frigid void beneath a thick floating plate of ice in one of the most remote regions on earth: the Pine Island Glacier.
What causes my team of scientific experts and me to focus on this seemingly innocuous location is a silent change that is unfolding and already affecting millions of people in their everyday existence, quietly threatening billions more. Ice sheets, those vast continental-sized slabs of ice in Greenland and Antarctica, are shrinking. The ice they are shedding is raising sea level across the globe. This is bad news. The good news is that the rise is gradual. My job is to understand the processes that cause ice sheets to shrink so that credible projections can be shared with policy makers and planners. If we get this right, societies will have the chance to adjust to rising sea level in a deliberate manner and minimize the human and economic impacts.
We are heading to a particularly remote corner of the planet, expecting to be greeted with bone-chilling temperatures, violent winds and dangerous crevasses (deep cracks in the ice) because this is where satellite data tells us that the Antarctic ice sheet is losing ice most rapidly. The Pine Island Glacier (called PIG, for short, from here on,) has nearly doubled it speed in the past 15 years and is thinning at rates of nearly 10 meters (30 feet) per year. It alone is responsible for 7 percent of the total global rate of sea level rise. The pattern of change satellites have captured shows that the changes are greatest at the coast and decrease inland. That means the trigger for these changes is located at the coast where the ice meets the ocean. PIG is 1200 meters (4000 feet) deep at the coast where it plows into the ocean forming a thick floating ice shelf. As the glacier forces its way into the frigid waters, the ocean resists its icy intrusion. The ice shelf can be thought of as a plug that limits the rate at which the PIG can drain the ice sheet. The little Dutch boy’s thumb inserted into the dike to hold back the sea is a particularly apt metaphor, in this case.
The problem is that the ocean is melting the underside of this PIG ice shelf, making it thinner and allowing the PIG to flow faster. This is what we’ve come to study. This is where the key to ice sheet stability and future sea level will be revealed. Damn the wind, damn the cold, damn the crevasses—we are on a mission and we will get our answers. This is the level of drive and determination that is required to do the work we have given ourselves.
In future blog posts, we’ll write about who we are, what we plan to do and, inevitably, how our initial plan changes as we wrestle with Mother Nature. For now I hope this captures your interest and sets the stage. I have had the luxury this year (this will be my sixteenth Antarctic expedition I’ve led) of enjoying Thanksgiving with my family, but already my mind is turning southward and my packing occupies a large corner of my bedroom. Yesterday was my last day in the office and I couldn’t leave with the others who were thinking most about tomorrow’s Thanksgiving pleasures until I felt all the unfinished work I left behind could withstand a two-month hiatus. It felt strange to close the office door that final time, but once I imagined the house lights being turned down on all the other work, I could feel the glare of the stage lights being cranked up to their full brightness on this field expedition. It’s showtime! The waiting and planning are over and this adventure is about to begin.