BYU geologist solves mystery of glaciers that grew while Asia heated upAugust 28, 2009Ice, when heated, is supposed to melt. That's why a collection of glaciers in the Southeast Himalayas stymies those who know what they did 9,000 years ago. While most other Central Asian glaciers retreated under hotter summer temperatures, this group of glaciers advanced from one to six kilometers. A new study by BYU geologist Summer Rupper pieces together the chain of events surrounding the unexpected glacial growth. "Stronger monsoons were thought to be responsible," said Rupper, who reports her findings in the September issue of the journal Quaternary Research. "Our research indicates the extra snowfall from monsoonal effects can only take credit for up to 30 percent of the glacial advance." As Central Asia's summer climate warmed as much as 6 degrees Celsius, shifting weather patterns brought more clouds to the Southeast Himalayas. The additional shade created a pocket of cooler temperatures. Temperatures also dropped when higher winds spurred more evaporation in this typically humid area, the same process behind household swamp coolers. The story of these seemingly anomalous glaciers underscores the important distinction between the terms "climate change" and "global warming." "Even when average temperatures are clearly rising regionally or globally, what happens in any given location depends on the exact dynamics of that place," Rupper said. The findings come from a framework Rupper developed as an alternative to the notion that glaciers form and melt in direct proportion to temperature. Her method is based on the balance of energy between a glacier and a wide range of climate factors, including wind, humidity, precipitation, evaporation and cloudiness. Gerard Roe and Alan Gillespie of the University of Washington are co-authors of the new study. Knowing how glaciers responded in past periods of climate change will help Rupper forecast the region's water supply in the coming decades. She and collaborators are in the process of determining how much of the Indus River comes from the vast network of glaciers far upstream from the agricultural valleys of India and Pakistan. "Their study can be used to help assess future glaciological and hydrological changes in the most populated part of our planet, which is a region that is now beginning to experience the profound effects of human-induced climate change," said Lewis Owen, a geologist at the University of Cincinnati who was not affiliated with this study. Brigham Young University |
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| Related Glaciers Current Events and Glaciers News Articles Research challenges for understanding landscape changes identified Nine research challenges and four research initiatives that are poised to advance the study of how Earth's landscapes change were unveiled today in a new report by the National Research Council. How much water does the ocean have? The calculation of variations in the sea level is relatively simple. It is by far more complicated to then determine the change in the water mass. Alberta's hidden valleys offer both resources and danger Alberta is crisscrossed with hidden glacial valleys that hold both resource treasures and potential danger. University of Alberta researcher Doug Schmitt discovered a 300 metre deep, valley hidden beneath the surface of the ground near the community of Rainbow Lake in northwestern Alberta. Iowa State scientist develops lab machine to study glacial sliding related to rising sea levels Neal Iverson opened his laboratory's walk-in freezer and said the one-of-a-kind machine inside could help scientists understand how glaciers slide across their beds. And that could help researchers predict how glaciers will react to climate change and contribute to rising sea levels. Antarctica glacier retreat creates new carbon dioxide store Large blooms of tiny marine plants called phytoplankton are flourishing in areas of open water left exposed by the recent and rapid melting of ice shelves and glaciers around the Antarctic Peninsula. Past climate of the northern Antarctic Peninsular informs global warming debate The seriousness of current global warming is underlined by a reconstruction of climate at Maxwell Bay in the South Shetland Islands of the Antarctic Peninsula over approximately the last 14,000 years, which appears to show that the current warming and widespread loss of glacial ice are unprecedented. Are the Alps growing or shrinking? The Alps are growing just as quickly in height, as they are shrinking. This paradoxical result could be proven by a group of German and Swiss geoscientists. Volcanoes played pivotal role in ancient ice age, mass extinction Researchers here have discovered the pivotal role that volcanoes played in a deadly ice age 450 million years ago. Perhaps ironically, these volcanoes first caused global warming -- by releasing massive amounts of carbon dioxide into the atmosphere. When they stopped erupting, Earth's climate was thrown off balance, and the ice age began. Arctic Sediments Show That 20th Century Warming Is Unlike Natural Variation The possibility that climate change might simply be a natural variation like others that have occurred throughout geologic time is dimming, according to evidence in a Proceedings of the National Academy of Sciences paper published today. Glacial melting may release pollutants in the environment Those pristine-looking Alpine glaciers now melting as global warming sets in may explain the mysterious increase in persistent organic pollutants in sediment from certain lakes since the 1990s, despite decreased use of those compounds in pesticides, electric equipment, paints and other products. More Glaciers Current Events and Glaciers News Articles |
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