There has been much discussion and confusion about global climate change. With an upcoming lecture and planetarium show on the topic, you have an opportunity to discover the facts and whether or not you should be concerned about the climate. This month we invite you to learn more about ice and glaciers, and the effect these have on our planet.
Ice Planet: Earth
On Wednesday, May 26 at 6:30 p.m. Dr. Mark Fahnstock will discuss the changes of our planet’s ice cover, specifically how it has changed over the past year, decade, and century. Dr. Fahnstock, who studies the glaciers of Greenland and the Antarctic, explains his research to the public. Don’t miss his lecture and the chance to learn more about global warming and our planet’s weather.
If you are interested in global climate change, the Poles are the place to watch because changes there can have a dramatic effect on the whole planet. When ice turns to water, it changes from a reflector to an absorber of solar radiation. When water turns to water vapor, it becomes a powerful greenhouse gas. When water vapor forms clouds, it becomes a reflector once again.
In 2007-2009, countries around the world celebrated the International Polar Year with expanded funding for research on Earth’s changing poles. On Memorial Day weekend, the Burke Baker Planetarium opens a new Ice Worlds show featuring what has been learned about the Arctic and Antarctic in the past two years.
Understanding the role of ice on our world is the first step in understanding how water amplifies any climate change. Ice Worlds is a beautiful show, including ice imagery from Earth’s poles and from the different ice-covered worlds in our solar system.
On July 21, scouts, summer campers and Ecoteens had a chance to get their most pressing climate questions answered from Ian Joughin, the leader of the Greenland Glacier Expedition that Chris has been writing about here through a live satellite link to the campsite in Greenland; later that night, adults got their turn. You can listen in, below.
The team is now back from the Greenland; here’s Chris’ last post on what they learned.
North Lake and the Journey Home
It has been a whirlwind since my last post—a hectic final week on the Greenland ice sheet studying two glacial lakes, a helicopter transfer back to the town of Ilulissat, and a long series of flights taking us home. Warm socks and down jackets are now a thing of the past—I’m typing this dispatch in 87-degree heat in Seattle (I know that’s not really hot for Texans, but it’s quite a tough adjustment for me after a month of subfreezing temperatures!)
Our final week on the ice was dedicated to exploring two nearby lakes, one of which had recently drained (dubbed “North Lake”) and another that was partially full of water when we arrived (dubbed “North North Lake”).
North Lake made the news earlier this year when Dr. Sarah Das (Woods Hole Oceanographic Institution) and Dr. Ian Joughin (University of Washington Applied Physics Lab/Polar Science Center) published a pair of papers in the journal Science about the spectacular draining event that they captured with their instrumentation in July 2006. That summer, a giant hole called a moulin opened up in the lake bed and drained the entire water volume (which is a lot; this lake is several kilometers long!) in an hour and a half. This year, the lake was already empty when we arrived (in fact, we had already heard from colleagues that it drained on July 10, the day we arrived at South Lake camp), so the research team had the freedom to explore the empty lake basin on foot.
Our visits to the North Lake basin revealed a bizarre landscape of car-sized blocks, canyons, rivers and waterfalls. The variation in the landscape on the ice sheet, particularly in the drained lake beds, is staggering. I expected it to be, well, flat, and white.
What we saw was quite different—towering blocks of pushed-up ice, rivers of freezing melt water carving their way through 60-foot deep canyons, gaping bottomless cracks and holes. The color of the ice ranges from opaque white to clear to bluebird blue. To my glaciologist companions, the landscape was also an open book. The blocks indicate where major cracks occurred (the blocks are pieces of the ice sheet that are broken loose during the cracking), and the rivers lead us to the crevasses (cracks) or holes (moulins) where the water was still pouring through the ice sheet to the bedrock. If you put your ear to the cracks, you can hear the water echoing in the depths.
It will still be some time before the final picture of the 2008 lake draining can be told. The scientists had only a brief amount of time to examine their instruments and prepare them for another year of data collecting before we had to pack up and fly out. In the coming months, scientists will be examining the data their instruments collected over the previous year. Dr. Mark Behn, a scientist from the Woods Hole Oceanographic Institution’s Geology and Geophysics department (and resident “icequakes” expert), had this comment about the data he did look at:
“Even with a 10 minute look, I can see that the quality of the data is good, which tells me the instruments are working. We can also see the timing of large cracking events that drain the lakes, which stand out as dramatic spikes on the record.”
Thank you to everyone who came in to the museum on July 21 to talk with moderator Twila Moon and Dr. Ian Joughin live from the ice. Stay tuned for future Live from the Poles expeditions on the Polar Discovery website. Until then, best wishes and thanks again for reading,
Our guest blogger today is Chris Linder, a Research Associate at the Woods Hole Oceanographic Institution in Massachusetts. He is the project manager and field photographer for the National Science Foundation-sponsored Live from the Poles project. Today – in addition to sending us weekly updates -Chris and fellow researcher Dr. Ian Joughin made a live call to our summer campers in the Burke Baker Planetarium; we hope to post the audio from the call here soon. If you’ve got questions of your own, visit us tonight – they’ll be calling us back. For now, here’s more from Chris, from the ice sheet:
The camp at North Lake
We have been camping on the ice sheet for over a week now, and it’s amazing to think how familiar this environment now seems, especially compared to how foreign it felt when I stepped off the helicopter.
Some of the peculiarities of living on a 3,000-foot thick slab of ice:
– Water: you don’t have to carry a water bottle on a hike, just a cup. The water is the best tasting I’ve ever had.
– Cooking: no refrigeration required! We made a no-bake cheesecake the other night and it was quite a treat. Just left it outside the cook tent to chill…
– Slippery tents: instead of using tent stakes to secure the tents, we use ice screws, which are 6-inch metal screws. The problem is, they heat up in the sun and melt out after a day, so we spend a lot of time repositioning the ice screws.
– No night: this is a tough one—the 24 hours of daylight make it hard to sleep and it’s easy to forget what time it is.
The past week has been a busy one—we typically wake up at 8 a.m. and sometimes don’t finish work until 1-2 a.m. The science team has been working nonstop to refurbish their long-term instruments and survey the terrain by foot and air. They successfully installed two new instrument towers on the shores of the recently drained South Lake, which will measure the weather, icequakes (using a seismometer), and the movement of the ice sheet (using a sensitive GPS). For more information about the tools our science team uses to track moving ice, visit the Polar Discovery tools page
View of a glacial lake from a helicopter
We also completed an hour-long helicopter survey of 20 nearby lakes. An aerial perspective gives you so much information that you can’t get from either the ground or from a satellite. You can see immediately the water level in a lake, count the number of inflow channels, and see where the lake is draining (if at all). The weather cleared during the survey and we had magnificent views of the glacial lakes – full ones, empty ones, and draining ones.
On July 16, we disassembled our carefully constructed home at South Lake and packed everything up for a move to North Lake. Although much of the work will be similar to what we did at South Lake (removing existing instruments, assembling new ones, and field mapping by foot and helicopter), the research team is expecting to see different processes at work here.
Last year, South Lake drained through a huge downstream channel, while North Lake gushed through a gaping hole called a moulin right in the center of the lake. This year, new observations at South Lake confirmed that the water primarily drained through a huge crack that ran right through the lake.
In the coming days, the science team is hoping to piece together this year’s story about North Lake, how it is similar and different from South Lake, how this knowledge can help to understand the thousands of glacial lakes that form on the ice sheet each summer, and what conclusions can be passed along to researchers modeling the global climate. Don’t forget to visit Polar Discovery to see daily photo essays!