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| Malaspina Glacier (from space) is a piedmont glacier: it's along the foot of a mountain range. Credit: NASA |
Expedition to the Gulf of Alaska: Scientists Study Coastal Mountains and Glaciers
Geologists aboard the scientific ocean drilling vessel JOIDES Resolution have embarked on their next adventure: studying glaciers to learn how Earth's geologic processes relate to the planet's climate history.
In the waters near Alaska's stunning coastal glaciers, the researchers are on Integrated Ocean Drilling Program (IODP) Expedition 341: Southern Alaska Margin Tectonics, Climate and Sedimentation.
The ship set sail today from Victoria, British Columbia. The expedition will conclude on July 29, 2013.
"Its scientists are examining the relationship between mountain-building, glaciation and climate," says Jamie Allan, program director in the U.S. National Science Foundation's (NSF) Division of Ocean Sciences, which supports IODP.
"This interplay happens not only in Alaska but in other parts of the world," says Allan. "New insights into these processes will help scientists better understand climate history and change, and how mountain landscapes form."
Led by co-chief scientists John Jaeger of the University of Florida and Sean Gulick of the University of Texas at Austin, an international team of researchers will collect and study sediments from five locations in the Gulf of Alaska.
They will investigate interactions between long-term climate change, including the fluctuations of large glaciers, and how mountains form.
The geologists will also conduct research on the transport of sediments from the mountains to the deep sea.
Because glaciers can erode and carry with them large amounts of rock, these rivers of ice can dramatically alter the landscape.
By rapidly decreasing the overall amount of rock in areas they scour, glaciers can also alter mountain ranges and cause uplifting--sometimes in less than one million years. In geologic terms, a relatively short time span.
"Mountains grow when numerous faults thrust layers of rock on top of each other," Gulick says. "We're asking whether this increases in locations with lots of erosion, such as beneath Alaska's glaciers."
The mountains of southern Alaska "have the perfect combination of large glaciers and rapidly uplifting mountains to test this idea," says Jaeger.
"We know very little about the long-term history of these glaciers," he says, "relative to what we know about other large ice sheets in, for example, Greenland and Antarctica."
The scientists are also comparing the advance and retreat of the Northern Cordilleran Ice Sheet with those of other major ice sheets. During the last 2.6 or so million years, the Cordilleran Ice Sheet periodically covered a large part of North America.
They also plan to obtain a record of Earth's magnetic field reversals recorded in the Gulf of Alaska, and look at ocean circulation changes and their effects on Earth's carbon cycle during transitions into and out of ice ages.
"Thousands of tourists sail through the Gulf of Alaska each year to see the dramatic landscapes created by these glaciers," Jaeger says.
Jaeger hopes that, in addition to many scientific benefits, "the findings from this expedition will provide tourists with a sense of how dynamic that landscape truly is."
The Integrated Ocean Drilling Program (IODP) is an international research program dedicated to advancing scientific understanding of the Earth through drilling, coring and monitoring the subseafloor.
The JOIDES Resolution is a scientific research vessel managed by the U.S. Implementing Organization of IODP (USIO). Texas A&M University, Lamont-Doherty Earth Observatory of Columbia University and the Consortium for Ocean Leadership comprise the USIO.
IODP is supported by two lead agencies: the U.S. National Science Foundation and Japan's Ministry of Education, Culture, Sports, Science and Technology.
Additional program support comes from the European Consortium for Ocean Research Drilling, the Australia-New Zealand IODP Consortium, India's Ministry of Earth Sciences, the People's Republic of China's Ministry of Science and Technology, the Korea Institute of Geoscience and Mineral Resources and Brazil's Ministry of Education.
-NSF-
