News from the polar regions in July includes efforts to better model and predict ice sheet dynamics and climate change, volcanic activity in the Arctic, and trouble for penguins and the marine species of the Southern Ocean. Missed these stories the first time? Read on!
As part of an international scientific contest, some of the world’s most renowned institutes on climate research are making forecasts and predictions for the Arctic sea ice summer minimum by means of different methods and climate models. Climate scientists from the Alfred Wegener Institute for Polar and Marine Research have concluded that this summer’s sea ice minimum will be lower than that of 2005 (the second lowest year on record). The chance of 2008’s minimum breaking last year’s record is about 8 percent. Researchers were careful to note that while these predictions are based on long-term data and mathematical models, they are, in fact, forecasts and not certainty.
One piece of the climate change prediction puzzle that continues to challenge scientists is understanding and modeling the flow of ice sheets and glaciers. A recent workshop organized by the European Science Foundation brought together glaciologists, geologists, and experts in other crystalline materials to discuss progress and future research objectives. To better understand ice sheet dynamics, researchers must revise their current model and focus on the behavior of organized groups of ice crystals called grains. Improved models will lead to better predictions of global ice cover that can be used in climate modeling and forecasting. In addition, Greenland’s ice sheet continues to be a topic of interest, as researchers continue to investigate the role of meltwater in increasing glacial movement and whether or not the accelerated melting contributes to sea level rise.
Scientists studying climate change have a new source of information: mussel shells. The new discipline, called molluskan sclerochronology, analyzes annual and even daily growth patterns in the shells. These growth patterns show changing nutritional conditions, temperature fluctuations, and environmental pollution. Mollusks are found all over the world, with some fossilized shells dating back 500 million years ago. The geographic and temporal range of these organisms allows for a thorough reconstruction of climatic and oceanic conditions around the world.
Another piece of evidence in the quest to document past climate change comes in the form of a 150-meter ice core pulled from the McCall Glacier in the Arctic National Wildlife Refuge. The core, the longest extracted from an Arctic glacier in the United States, spans the entire depth of the glacier and may cover up to 200 years, back to a time when such glaciers were actually growing. McCall Glacier has been studied since the International Geophysical Year (1957-1958), providing a wealth of research history to complement the data from the sample.
Okmok Volcano, in the eastern Aleutian islands, erupted on Saturday, July 12, 2008, with little warning. The initial ash and gas-rich plume, which caused heavy ash fall and the cancellation of flights, is now over Montana, but the volcano has continued to produce explosions and ash plumes through a newly created vent. Air travel and direct study of the area remains hazardous, so scientists are using a combination of seismic GPS instruments and weather and radar satellites to track progress. Activity is expected to continue for days or weeks.
Researchers have discovered that underwater volcanic eruptions can be more explosive than previously thought. While it was previously assumed that the intense weight and pressure of water would prevent the formation of pyroclastic deposits (splintered, fragmented rock), a research team led by Woods Hole Oceanographic Institute have discovered evidence of such formations in the Gakkel Ridge, deep below the ice-covered surface of the Arctic Ocean. Researchers now wonder if this means that these violent explosions are more common than previously thought, or if the Gakkel Ridge has unusual characteristics that make such explosions possible.
New genetic research of native North Americans provides additional support for the hypothesis that a small group of subarctic Athapaskan natives migrated to the southwestern United States approximately 500 years ago. The migrants successfully assimilated with the groups already living in the Southwest, affecting only their language and their genetic makeup. Since the migrants did not alter the physical landscape, architecture, or cultural practices of the existing populations, it has been difficult for anthropologists to completely understand the migration. This genetic analysis of the Y-chromosome thus fills a gap in the archaeological history of the migration.
Finally, the U.S. Geological Survey recently predicted that the Arctic Circle holds an estimated 90 billion barrels of recoverable oil, which could meet current world demand for almost three years. The area could also contain 1,670 trillion cubic feet of natural gas. As Arctic sea ice continues to decline, international competition for these resources is increasing. Of course, any exploration and development of the area would come at a price: the possible loss of biodiversity and increased threat to Arctic species such as the polar bear.
While sea ice, ice sheet dynamics, and climate change continue to dominate news from the Arctic, penguins and other marine life have been the focus of much Antarctic-related news. We recently reported a study in which emperor penguins were fitted with digital electrocardiogram recorders while diving in the waters of McMurdo Sound. The study aimed to learn more about the bird’s adaptations to low oxygen during diving.
Sadly, more than 400 penguins have been found dead on beaches in Rio de Janeiro, Brazil in the past few months. Many are young. While it is common to find penguins, both dead and alive, washed onto the beaches, this year has shown a marked increase in numbers. Scientists, veterinarians, and other experts are divided over possible causes, including overfishing, oil from the offshore Campos oil field, other pollutants, or global warming.
These issues are not just affecting penguins in Patagonia and Brazil, but worldwide as well. In a recent paper, Dee Boersma, a University of Washington biology professor, discusses problems such as oil pollution, depletion of fisheries, explosive coastline development, and climate change and the impact on the 16-19 penguin species worldwide. She notes that many of these species have experienced dramatic declines in recent years, in some cases, as much as 50-75%. Boersma advocates an international effort to monitor penguin species, the threats facing them, and the implications for overall ocean health.
Boersma’s recommendation may be more feasible thanks to new technology presented at this year’s Royal Society Summer Science exhibition. Scientists at the University of Bristol have devised an intelligent, visual surveillance system that allows them to non-intrusively monitor African penguins on Robben Island in South Africa. The system uses biometric data generated from unique black spot patterns found on the chests of African penguins. The data can be used by scientists to identify individual penguins from video or still images. While there are still some limitations to the system, the technology can, in principle, be extended to any species with complex surface patterns and will provide a much more sophisticated alternative to conventional tagging techniques.
As the Wilkins Ice Shelf continues to experience disintegration, scientists are examining the impact of changing sea ice on marine species. As Antarctic winter sea ice declines, more icebergs will scour, scrape, and disturb the seabed. This is because unless the icebergs are locked into position by winter sea ice, they are continuously pushed around by winds and tides and often crash into the seabed. While some disturbance is believed to create a range of habitats populated by a wide variety of creatures, an increase in iceberg scour would negatively affect the type and number of marine organisms found on the diverse seabed. The Southern Ocean seabed is home to 80% of all Antarctic life.
Additionally, declining sea ice means trouble for migratory whales such as the Antarctic minke whale, the Blue Whale, and humpback whales. These whales feed mainly on krill, a species that is dependent on sea ice. As the extent of sea ice shrinks, whales will have to swim further for less food. The World Wildlife Fund, who released the July report, recommends taking action on climate change as well as reducing other threats to whales such as fishing, pollution, ocean noise, and the “scientific whaling” conducted by Japan.
Marine life and sea ice isn’t the only Antarctic news this month. Geologists sampling rock specimens in the Transantarctic Mountains found a lone granite boulder atop the Nimrod Glacier. The specific, coarse-grained specimen was found to be very similar to a unique belt of igneous rock that stretches across North America. The serendipitous discovery provides physical evidence to support the SWEAT hypothesis, which states that parts of Antarctica were connected to North America hundreds of millions of years ago in the supercontinent Rodinia.
A discovery of well-preserved ostracods has excited scientists for both the significance of the fossil preservation and the implications for Antarctica’s paleoclimate. These small organisms were found in the Dry Valleys of the East Antarctic region, with their soft tissue preserved. Researchers believe that the ostracods inhabited an ancient (14 million year old) lake and that their discovery indicates that the region was much warmer, with tundra-like conditions.
Finally, the cost of gasoline is affecting not just consumers – but polar researchers as well. We recently reported on a recent article that detailed the large fuel budgets needed to conduct research in these remote areas – and hinted that cuts in new programs may be likely.
Know of another significant news story from July that you’d like to share? Reactions to one of the stories discussed here? Post a comment – we’d love to hear from you!
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