Posts tagged climate change
CU scientists study high-Asian snowpack for GW clues
Dec 7th
WATER RESOURCES IN ASIA MOUNTAINS
A University of Colorado Boulder team is partnering with the United States Agency for International Development to assess snow and glacier contributions to water resources originating in the high mountains of Asia that straddle 10 countries.
Richard Armstrong and Mark Williams, the two faculty members leading the four-year study, said the aim is to provide a comprehensive and systematic assessment of freshwater resources in the so-called “High Asia” region, which encompasses five mountain ranges and watersheds totaling roughly 1 million square miles. The area under study is roughly equal to one-third of the contiguous United States.
This assessment will be crucial in helping to forecast the future availability and vulnerability of water resources in the region, beginning with accurate assessments of the distinct, separate contributions to river discharge from melting glacier ice and seasonal snow. Such data ultimately will provide a better understanding of the timing and volume of runoff in the face of climate change, said the CU-Boulder researchers.
The High Asia mountains funnel water into such major river basins as the Ganges, Brahmaputra, Indus, Amu Darya and Syr Darya. The High Asian mountain ranges under study include the Himalaya, Karkoram, Hindu Kush, Pamir and Tien Shan. The mountain ranges straddle Bhutan, Nepal, China, India, Pakistan, Afghanistan, Kazakhstan, Uzbekistan, Kyrgyzstan and Tajikistan.
Through the partnership, scientists and students within the 10 countries will carry out collaborative research with CU-Boulder scientists. The project also will support satellite data processing by CU-Boulder staff and trainings for local institutions and observers within the study area to collect water and precipitation samples for the project.
While about one-third of the world’s population depends to some degree on fresh water within the High Asia hydrological system, not enough data exists on river and stream flows and the contribution of seasonal snow and glacier melt to paint an accurate picture of the water resources there, said Armstrong, a senior research scientist at CU-Boulder’s National Snow and Ice Data Center, or NSIDC. ”
The team requires an accurate quantitative portrait of each major river basin and sub-basin in High Asia. The Indus River, for example, which is fed by waterways from the Himalaya, Karakorum and Hindu Kush mountain ranges, comes together at the city of Besham, Pakistan, “where it immediately turns into the largest irrigation system in the world,” said Williams. “The sources of water in High Asia feeding the major foothill regions where most of the people live are really the crux of this study.”
Armstrong said there is a lot of misinformation in the public arena regarding glaciers, including reports that glaciers in the Himalaya are receding faster than anywhere else in the world and, if this rapid melting continues, rivers are on track to first flood and then dry up. “Those reports simply are not true,” Armstrong said.
USAID is an independent United States government agency that provides economic, development and humanitarian assistance around the world in support of the foreign policy goals of the United States.
“USAID wants to know how the High Asia water resources affect local populations,” said Armstrong, also a fellow at the CU-headquartered Cooperative Institute for Research in Environmental Sciences. “They are looking at this challenge from a sustainability perspective, including what is going to happen to rivers like the Indus and the Brahmaputra in the next 20 years.”
The researchers will use remote-sensing satellite data from NASA, the European Space Agency and the Japanese Space Agency to develop time-series maps of seasonal snowfall amounts and recent changes in glacier extent, said Williams, a fellow at CU-Boulder’s Institute of Arctic and Alpine Research and a CU-Boulder geography professor. They also will use local meteorological and river discharge data from throughout the High Asia study area.
“What’s really driving this study are questions about water security,” said Williams. “There is a lot of international interest in accurate water resource data from the High Asia region and what the water security consequences are, since water conflicts between countries can escalate rapidly. This study should provide answers as to what is real and what is false.”
“Once we have a picture of recent and current conditions, we can go forward and run computer ‘melt models’ based on the temperatures at various elevations, giving us trends in snowmelt and glacier melt by region and time,” said Armstrong. “That’s when we start to come up with water volumes for individual rivers and streams from both melting snow and ice.”
The modeling results will be verified using geochemical and water isotope “tracer” techniques developed at CU that allow researchers to follow water as it courses through mountain landscapes. Previous studies by Williams and his research group showed high mountain groundwater in Colorado dominated by snowmelt can be locked underground for decades before emerging into downstream waterways. “These isotopic and geochemical measurements provide unique fingerprints, allowing a CSI-like approach to tracing water sources,” said Williams.
Critical to the project is the university’s expertise in remote sensing research through NSIDC — including assessing changes in Earth’s snow and ice cover — and INSTAAR’s research on the physical, chemical and biological processes in “critical zones,” which are the areas between treetops and groundwater. INSTAAR administers both the Long-Term Ecological Research site at Niwot Ridge west of Boulder and the Critical Zone Observatory project in the Boulder Creek watershed for the National Science Foundation.
One of the biggest project challenges will be to obtain data from some of the most remote regions on Earth, said Williams. The water, rain and snow samples collected by collaborators within the study area will be sent back to CU-Boulder for analysis.
The research will bring together scientists and government officials in the countries of High Asia to coordinate and compare results on what part of river flows come from glaciers and seasonal snow. This sharing of information is important because the rivers of Asia can cross several country borders. USAID support will contribute to the research and coordination and CU-Boulder will make its archived and new data on snow and ice easily available to all the countries and their citizens.
The CU team will hire Asian project managers and collaborate with research scientists affiliated with various Asian institutes. “We already have some good scientific contacts in the region, people we know who are reliable and who can deliver,” said Armstrong.
A number of CU undergraduate and graduate students will be involved in the study and support will be available to Asian students by way of the funding provided to Asian project partners.
“One of the main project goals is to transfer scientific understanding to people in the region who can continue these measurements and analysis once the USAID project is finished,” said Armstrong. “The idea is to provide the local population with the information they need to make decisions that will increase sustainability as land use and climate change.
CU Boulder scientists uncover molded brass artifact from Asia in Alaska
Nov 14th
UNEARTHED AT ALASKA ARCHAEOLOGY SITE
A team of researchers led by the University of Colorado Boulder has discovered the first prehistoric bronze artifact made from a cast ever found in Alaska, a small, buckle-like object found in an ancient Eskimo dwelling and which likely originated in East Asia.
The artifact consists of two parts — a rectangular bar, connected to an apparently broken circular ring, said CU-Boulder Research Associate John Hoffecker, who is leading the excavation project. The object, about 2 inches by 1 inch and less than 1 inch thick, was found in August by a team excavating a roughly 1,000-year-old house that had been dug into the side of a beach ridge by early Inupiat Eskimos at Cape Espenberg on the Seward Peninsula, which lies within the Bering Land Bridge National Preserve.
Both sections of the artifact are beveled on one side and concave on the other side, indicating it was manufactured in a mold, said Hoffecker, a fellow at CU-Boulder’s Institute of Arctic and Alpine Research. A small piece of leather found wrapped around the rectangular bar by the research team yielded a radiocarbon date of roughly A.D. 600, which does not necessarily indicate the age of the object, he said.
“I was totally astonished,” said Hoffecker. “The object appears to be older than the house we were excavating by at least a few hundred years.”.
Hoffecker and his CU-Boulder colleague Owen Mason said the bronze object resembles a belt buckle and may have been used as part of a harness or horse ornament prior to its arrival in Alaska. While they speculated the Inupiat Eskimos could have used the artifact as a clasp for human clothing or perhaps as part of a shaman’s regalia, its function on both continents still remains a puzzle, they said.
Since bronze metallurgy from Alaska is unknown, the artifact likely was produced in East Asia and reflects long-distance trade from production centers in either Korea, China, Manchuria or southern Siberia, according to Mason. It conceivably could have been traded from the steppe region of southern Siberia, said Hoffecker, where people began casting bronze several thousand years ago.
Alternatively, some of the earliest Inupiat Eskimos in northwest Alaska — the direct ancestors of modern Eskimos thought to have migrated into Alaska from adjacent Siberia some 1,500 years ago — might have brought the object with them from the other side of the Bering Strait. “It was possibly valuable enough so that people hung onto it for generations, passing it down through families,” said Mason, an INSTAAR affiliate and co-investigator on the Cape Espenberg excavations.
The Seward Peninsula is a prominent, arrowhead-shaped land mass that abuts the Bering Strait separating Alaska from Siberia. The peninsula was part of the Bering Land Bridge linking Asia and North America during the last ice age when sea level had dropped dramatically, and may have been used by early peoples as a corridor to migrate from Asia into the New World some 14,000 years ago.
The artifact was discovered in August by University of California, Davis, doctoral student Jeremy Foin under 3 feet of sediment near an entryway to a house at Cape Espenberg. Other project members included Chris Darwent of UC Davis, Claire Alix of the University of Paris, Nancy Bigelow of the University of Alaska Fairbanks, Max Friesen of the University of Toronto and Gina Hernandez of the National Park Service.
“The shape of the object immediately caught my eye,” said Foin, who spotted the soil-covered artifact in an archaeological sifting screen. “After I saw that it clearly had been cast in a mold, my first thought was disbelief, quickly followed by the realization that I had found something of potentially great significance.”
The CU-led excavations are part of a National Science Foundation-funded project designed to study human response to climate change at Cape Espenberg from A.D. 800 to A.D. 1400, a critical period of cultural change in the western Arctic, said Mason. Of particular interest are temperature and environmental changes that may be related to Earth’s Medieval Warm Period that lasted from about A.D. 950 to 1250.
“That particular time period is thought by some to be an analog of what is happening to our environment now as Earth’s temperatures are rising,” said Mason. “One of our goals is to find out how these people adapted to a changing climate through their subsistence activities.”
The Cape Espenberg beach ridges, wave-swept deposits made of sand and sediment running parallel to the shoreline that were deposited over centuries, often are capped by blowing sand to form high dunes. The Cape Espenberg dwellings were dug into the dunes and shored up with driftwood and occasional whale bones.
The team is examining the timing and formation of the beach ridges as well as the contents of peat and pond sediment cores to help them reconstruct the sea-level history and the changing environment faced by Cape Espenberg’s settlers. Information on past climates also is contained in driftwood tree rings, and the team is working with INSTAAR affiliate Scott Elias, a University of London professor and expert on beetle fossils, who is helping the team reconstruct past temperatures at Cape Espenberg.
While the hunting of bowhead whales was a way of life for Inupiat Eskimos at Barrow and Point Hope in northwestern Alaska 1,000 years ago, it is still not clear if the Cape Espenberg people were whaling, said Mason. While whale baleen — a strong, flexible material found in the mouths of whales that acts as a food filter — and a variety of whale bones have been found during excavations there, the sea offshore is extremely shallow and some distance from modern whale migration routes. However, there is evidence of fishing and seal and caribou hunting by the group, he said.
The Inupiat Eskimos are believed to have occupied Cape Espenberg from about A.D. 1000 until the mid-1800s, said Hoffecker. They are part of the indigenous Eskimo culture that lives in Earth’s circumpolar regions like Alaska, Siberia and Canada.
The Cape Espenberg site has yielded a treasure trove of several thousand artifacts, including sealing harpoons, fishing spears and lures, a copper needle, slate knives, antler arrow points, a shovel made from a walrus scapula, a beaver incisor pendant, ceramics, and even toy bows and toy harpoons. The bronze artifact unearthed in August is currently under study by prehistoric metallurgical expert and Purdue University Assistant Professor H. Kory Cooper.
A video news story on the discovery is available by going to http://www.colorado.edu/news/ and clicking on the story headline. A podcast on the find can be found at http://www.colorado.edu/news/podcasts/
CU scientists: CO2 emissions a HUGE problem
Nov 4th
New calculations showing the global output of heat-trapping carbon dioxide gases jumped by the largest amount on record in 2010 is more evidence that society has made a choice to continue to accelerate climate change, say two University of Colorado Boulder experts.
The new figures calculated by the U.S. Department of Energy show the world pumped more than 560 additional tons of carbon into the atmosphere in 2010 than in 2009, an increase of 6 percent. There are currently 392 parts per million of CO2 in Earth’s atmosphere, a rise of more than 100 since the Industrial Revolution, said CU-Boulder Institute of Arctic and Alpine Research Director Jim White.
The CO2 rise is driven primarily by growing industry in China and India — the two highest users of coal — as well as the United States, said White. “While the world population growth has slowed, the use of fossil fuels continues at a record pace,” he said. Studies have shown Earth’s land temperatures have increased by 1.6 degrees Fahrenheit since the 1950s.
“While it is good news that the global economy continues to grow, we clearly have not taken greenhouse gases and climate change seriously,” said White, an expert on ice cores and climate change. Only a substantial and rapid global move toward alternative energies can slow the growth of CO2 emissions, he said.
“We are rolling the dice here, which is not a good way to plan for the future,” said geography Professor Mark Serreze, director of CU-Boulder’s National Snow and Ice Data Center and an expert on declining Arctic sea ice.
“The warning signs of climate change are all around us, and we have decided to ignore them,” said Serreze. “Humankind has made a choice to do nothing, and we can never go back to where we were again. As a consequence, we will have to adapt to change.”
For more information contact White at 303-492-2219 or james.white@colorado.edu, Serreze at 303-492 -2963 or serreze@kryos.colorado.edu or Jim Scott in the CU-Boulder media relations and news office at 303-492-3114.