(Université Laval press release, 17 February 2010) -- Quebec City - The southern limit of permanently frozen ground, or permafrost, is now 130 kilometers further north than it was 50 years ago in the James Bay region, according to two researchers from the Department of Biology at Université Laval. In a recent issue of the scientific journal Permafrost and Periglacial Processes, Serge Payette and Simon Thibault suggest that, if the trend continues, permafrost in the region will completely disappear in the near future.

The researchers measured the retreat of the permafrost border by observing hummocks known as "palsas," which form naturally over ice contained in the soil of northern peat bogs. Conditions in these mounds are conducive to the development of distinct vegetation—lichen, shrubs, and black spruce—that make them easy to spot in the field.

In an initial survey in 2004, the researchers examined seven bogs located between the 51st and 53rd parallels. They noted at that time that only two of the bogs contained palsas, whereas aerial photos taken in 1957 showed palsas present in all of the bogs. A second assessment in 2005 revealed that the number of palsas present in these two bogs had decreased over the course of one year by 86% and 90% respectively. Helicopter flyovers between the 51st and 55th parallels also revealed that the palsas are in an advanced state of deterioration over the entire James Bay area.

While climate change is the most probable explanation for this phenomenon, the lack of long-term climatic data for the area makes it impossible for the researchers to officially confirm this. Professor Payette notes, however, that the average annual temperature of the northern sites he has studied for over 20 years has increased by 2 degrees Celsius. "If this trend keeps up, what is left of the palsas in the James Bay bogs will disappear altogether in the near future, and it is likely that the permafrost will suffer the same fate," concludes the researcher affiliated to the Centre d'études nordiques.

Tagged: Arctic, News, Polar research: Reports and findings

(Randy Boswell/Canwest News Service via Nunatsiaq News, 26 February 2010)** -- Two U.S. scientists have published a radical new theory about when, where and how humans migrated to the New World, arguing that the peopling of the Americas may have begun via Canada’s High Arctic islands and the Northwest Passage — much farther north and at least 10,000 years earlier than generally believed. The hypothesis — described as “speculative” but “plausible” by the researchers themselves — appears in the latest issue of the journal Current Biology [available free], which features a special series of new studies tracing humanity’s proliferation out of Africa and around the world beginning about 70,000 years ago.

The idea of an ancient Arctic migration as early as 25,000 years ago, proposed by University of Utah anthropologists Dennis O’Rourke and Jennifer Raff [get paper here], would address several major gaps in prevailing theories about how the distant ancestors of today’s aboriginal people in North and South America arrived in the Western Hemisphere. The most glaring of those gaps is the anomalous existence of a 14,500-year-old archeological site in Chile, near the southern extreme of the Americas, that clearly predates the time when East Asian hunters are thought to have first crossed from Siberia to Alaska via the Bering Land Bridge at the end of the last ice age some 13,000 years ago.

The new theory may also have implications for a lingering Canadian archeological mystery. For decades, the Canadian Museum of Civilization has stood largely alone in defending its view that the Yukon’s Bluefish Caves hold evidence of a human presence in the Americas — tool flakes and butchered mammoth bones — going back about 20,000 years. The Utah scientists, pointing to genetic affinities between certain central Asian populations and New World aboriginal groups, suggest an Arctic coastal migration may have begun from river outlets in present-day north-central Russia.

Tagged: Arctic, News, Polar research: Reports and findings