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,
Recently, The Houston Museum of Natural Science has been working with the University of New Hampshire to create a new full-dome planetarium show – Ice Worlds (now showing). From the poles of the Earth to the exploration of other ice planets in our solar system, this film explores the state of ice and liquid water throughout the galaxy, and climate changes here on Earth. As part of the Ice Worlds program, we are featuring Ice Bulletins as visitors enter the planetarium theater. If you want to know what’s Hot on the Cold Poles, these are the best current events we have found.
Coastal areas with open water have more potential for wave action (as well as flooding and hurricanes) than a frozen shoreline. Studies from 1950-2000 have indicated a warming trend in the Chukchi and southern Beaufort Seas, which corresponds to a decrease in sea ice coverage. Longer, warmer seasons translate to less ice, and more open water, which in turn leads to more waves, floods, and storms.
The amount of water flowing through rivers to the Arctic Ocean in Eurasia has been increasing over the last 70 years. More recently, (2000-2004) this flow has increased even more. If the trend continues, some scientists predict this could impact the global climate, perhaps leading to the cooling of Northern Europe.
The warming of the Alaskan Arctic during the past 150 years has accelerated over the last three decades. This is expected to increase vegetation productivity in tundra if shrubs become more abundant; indeed, this transition may already be under way, according to local plot studies and remote sensing.
Using satellite radar interferometry observations of Greenland, scientists have detected widespread glacier acceleration below 66° north between 1996 and 2000, which rapidly expanded to 70° north in 2005. Accelerated ice discharge in the west and particularly in the east doubled the ice sheet mass deficit in the last decade from 90 to 220 cubic kilometers per year. As more glaciers accelerate farther north, Greenland’s contributions to sea-level rise will continue to increase.
The legendary passage was first navigated with great difficulty using a relatively small ship by explorer Roald Amundsen in 1903 to 1906. Predictions for the opening of the Northwest Passage have ranged from 2012 to 2080 at their most conservative. “We’re several decades ahead of schedule right now,” said Mark Serreze, a senior scientist at the University of Colorado’s National Snow and Ice Data Center, which monitors the region. Fully navigable, the Northwest Passage will make the trip 4,000 miles shorter for ships traveling between Europe and Asia, allowing them to avoid the Panama Canal. “The notion of coming to an ice-free Arctic Ocean even by 2030 is not totally unreasonable,” Serreze said.
The US Department of the Interior listed the polar bear as a threatened species under the Endangered Species Act based on studies claiming the loss of sea ice threatens, and will likely continue to threaten, polar bear habitat. The studies cite differences in sea ice from the fall of 1979 to the fall of 2007 and projected declines in sea ice by the middle of the 21st century. Although some females use snow dens on land for birthing cubs, polar bears are almost completely dependent upon sea ice for their sustenance. Any significant changes in the abundance, distribution, or existence of sea ice will have effects on the number and behavior of these animals and their prey. Canada has listed the polar bear as a “species of concern” since 2002 and is currently conducting a status review as of 2008.
The oil industry and support services withdraw water from freshwater lakes and ponds to build ice roads and pads in the Arctic for increased access to remote sites. This technique is important to the oil industry, in that it allows oil field development or maintenance, while avoiding the environmental disturbance associated with construction of gravel roads and pads. The decrease in the time during which ice roads can be used is due to a changing climate. Ice roads are constructed using water from ponds, lakes, and rivers. Rivers themselves are traversed using ice bridges. The industry must have all drilling equipment back to gravel bases before the ice road deteriorates. The season ends when the first ice bridge is washed out. The ice bridge failures are a function of melting further south in the stream’s headwaters.
Are melting glaciers causing sea levels to rise? A team from Utrecht University says no. A team from Woods Hole Oceanographic Institute is exploring that issue this month – check back here for updates from Chris Linder.
And you thought the Sun was harsh – “O” stars in the Rosetta Nebula “can be a hundred times the size and over a thousand times brighter” – and they destroy planets.