ALASKA'S COLUMBIA GLACIER RETREATING RAPIDLY

Tad Pfeffer (INSTAAR and CEAE) leads a research group that has documented the rapid tidewater retreat of the Columbia Glacier in Alaska, one of the fastest moving glaciers in the world. Since the early 1980s, Columbia Glacier has retreated nine miles from its original endpoint in the Pacific Ocean at Prince William Sound, and has reached flow speeds as high as 88 feet per day. The glacier is the largest single contributor to sea level rise among all North American glaciers, and accounts for about 10 percent of total glacial discharge from the Alaska/Yukon region each year.

The retreat of Columbia Glacier is part of a cyclic pattern of slow advance and abrupt retreat typical of Alaskan tidewater (or ocean-terminating) glaciers, according to Pfeffer. The abrupt retreat was probably triggered by long-term melt and thinning, occurring over the past century or so for the Columbia Glacier, he added.  The retreat of Columbia Glacier is being used as a model for apparently similar retreats now beginning on the outlet glaciers of southern Greenland. An additional question, Pfeffer said, is whether the same conditions causing the world-wide shrinkage of land-terminating glaciers will alter the cyclic pattern of tidewater glaciers, and prevent re-advance, either in Alaska or Greenland.  Since the retreat of Columbia Glacier began in the 1980s, the glacier has thinned up to 1,300 feet in places, and is increasingly influenced by the upward pressure of underlying seawater on the part of the glacier which extends into the ocean. Pfeffer estimates that the tidewater glacier is about halfway through its projected retreat. The glacier is predicted to fall back another nine miles over the next 20 to 25 years and then stabilize with its terminus near sea level.

Pfeffer and doctoral student Shad O’Neel have been working with other researchers to monitor the glacier using aerial photography, time-lapse photography, seismometers and other instruments. Both Pfeffer and O’Neel presented the group’s latest results at the American Geophysical Union conference in December.

CU News Release

T. Pfeffer: INSTAAR Biography

GIFFORD MILLER: RECIPIENT OF THE 2005 EASTERBROOK DISTINGUISHED SCIENTIST AWARD

Gifford Miller received the Easterbrook Distinguished Scientist Award at the Geological Society of America's (GSA) 2005 annual meeting. The award is given annually by the Society's Quaternary Geology and Geomorphology Division to an individual who has shown unusual excellence in published research, as demonstrated by a single paper of exceptional merit or a series of papers that have substantially increased knowledge in Quaternary geology or geomorphology. Recent recipients include Wallace Broecker, Victor Baker, Richard Alley, Tom Dunne, and Edward Keller. Miller's former advisor and INSTAAR fellow John Andrews wrote the citation, with contributions by nineteen individuals from several countries and with a variety of connections.

Image: Portrait of Gifford Miller

Citation & Response

G. Miller: INSTAAR Biography

METHANE GYRATIONS IN PAST 2,000 YEARS SHOW HUMAN INFLUENCE ON ATMOSPHERE

Dominic Ferretti, Jim White, and colleagues from the US, New Zealand, and Australia used pioneering stable isotopic techniques on air samples extracted from the tiny bubbles trapped in Antarctic ice cores to show that methane, a potent greenhouse gas in Earth's atmosphere, has been altered by humans over the past 2,000 years.  Atmospheric methane (CH₄) varied as expected over the past few centuries when methane concentrations in the atmosphere rose by nearly 300 percent and other greenhouse gas levels are known to have increased sharply due to human influences. But the results further back in time came as a shock.  Measurements of the stable carbon isotopes in methane (δ¹³C of CH₄) fluctuated much more than expected before the industrial revolution.  The gyrating ratio combined with other geochemical measurements are evidence for massive fires set by humans clearing land for agriculture and hunting for at least 2,000 years. A prominent feature is a huge drop in the the δ¹³C ratio from ca. 1500 to 1600 A.D., and this was attributed to decreased grassland and forest burning by indigenous peoples in the South and Central America Americas, whose population was devastated by diseases brought to the New World by European explorers.  The study is particularly important because methane increases have had the second highest impact on climate change over the past 250 years behind carbon dioxide, accounting for about 20 percent of the warming from all greenhouse gas increases.  Methane is more powerful than carbon dioxide on a per molecule basis in slowing the release of radiated heat away from Earth. Previous work by other groups indicates that methane emissions from wildfires are likely to be higher during warm and dry periods, such as El Niño events, and may therefore increase with future climate change.

Ferretti has a joint appointment with INSTAAR and the National Institute of Water and Atmospheric Research (NIWA) in Wellington, New Zealand. Other collaborating institutions include Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO), Australia's Department of the Environment and Heritage and the National Oceanic and Atmospheric Administration (NOAA). 

The paper was published in the 9 September issue of Science. Image: Central field tent at Law Dome, Antarctica where drilling took place. Snow accumulation at Law Dome is very high (greater than 1m/year) enabling the extraction of well dated and high resolution ice cores for greenhouse gas analysis. (Photo: Vin Morgan, Australian Antarctic Division, ACE, CRC).

CU News Release

NIWA Press Release

CSIRO Media Release

Science Magazine: Abstract

ABC Online Australia:
Interview with D. Ferretti

OZONE AND THE OCEANS

Shelly Sommer created a poster display for the Discovery Science Center that describes a project, led by Detlev Helmig, to measure ozone fluxes over the oceans. The poster also explains the role of ozone in the troposphere vs. the stratosphere. The hands-on science center is located in Fort Collins, Colorado and serves 35,000 visitors each year; many attendees are children from northern Colorado and Wyoming.

A companion web site, Ozone and the Oceans, was created with the assistance of David Lubinski. The site is an educational resource for grades 5-12 that describes the science, introduces team members, and provides updates on the project, a glossary, and downloadable PDFs of the Science Center posters. The site has been added to the Digital Library for Earth Science Education (DLESE) and the National Science Digital Library.

Image: The research vessel Ronald H. Brown. The instruments used in this project will be fixed to the bow tower and jackstaff on the foredeck of the ship. Photo by Chris Fairall (NOAA).

Ozone & the Oceans

Discovery Science Center

DLESE

NSF Digital Library

D. Helmig: INSTAAR Biography

NEW MARINE SUBSTRATES DATABASE FOR US ATLANTIC CONTINENTAL MARGIN

Chris Jenkins and colleagues at the USGS released the first regional coverage of the usSEABED database, a large compilation of samples data on marine substrates for the US Exclusive Economic Zone (200 nautical miles out from the coast), in this case for the Atlantic margin. The database is now widely used by agencies and others for mapping, understanding, and managing the offshore region. The continental shelf in particular, serves a variety of purposes: recreation, benthic habitats conservation, fisheries, commerce, transportation, national defense operations, waste disposal, and engineering activities. The usSEABED database is built using dbSEABED processing software created by Jenkins. It has companion databases built along similar lines: for Australia auSEABED and globally goSEABED. The databases rely on pre-existing data, both published and unpublished, which the software has been able to integrate and quality filter. The usSEABED database, using the dbSEABED program, differs from other US databases in that it incorporates both numerical and linguistic data on sediment texture, biology, seafloor characteristics such as hardness or sediment ripples, acoustic properties, and geochemical and geotechnical analyses. This broad-based approach increases the data density over the seabed, allowing for more complete maps and information. Future regional releases will be for the Pacific, Gulf of Mexico and Alaskan margins.

Image: SEABED data for a portion of the Atlantic coast showing locations of both extracted (numeric, lab-based analyses) and parsed (word-based descriptions) outputs.

USGS Data Release

USGS Factsheet (PDF)

dbSEABED

Diane McKnight (INSTAAR & CEAE) and Jeff Wong (CEAE) spoke with KUNC's Gavin McMeeking about the pervasive pollution of Colorado mountain streams by mining and the potential for remediation by environmental engineers. More than 19,000 abandoned mines in Colorado have polluted more than 7500 miles of streams (equal to the distance from Los Angeles to Sydney Australia). This summer McKnight and Wong are concentrating on Peru Creek in Summit County (Snake River Watershed). The creek's bed near an abandoned mine is covered by metal oxides at a level that prevents algal growth and is lethal to aquatic life. There are no stream insects and thus, no fish and riparian birds. To help understand the transport of metals, Wong set up a salt injection tracer experiment that mimics the behavior of some non-reactive solutes, such as zinc, and helps in quantifying how much iron oxide is being deposited. Undergraduate students in the CU Biomathematics Scholars program based at INSTAAR participated in the downstream sample collection. Computer modelling of the experiment's data will provide ideas for remediation, but much remains to be learned and eventually millions of dollars will be needed to clean up this stream and many others. Ironically, another hurdle to successful remediation is the Clean Water Act, which mandates that any group working on remediation becomes liable for the environmental damage. Congressman Mark Udall has proposed a "good samaritan" amendment but it has stalled in Congress. Two other INSTAAR grad students, Andrew Todd and Chi Yang (CEAE), are studying the combined effects of limited prey and metal toxicity on fish and birds in other less severely impacted stream reaches in the larger Snake River Watershed.

Aired on KUNC 04 August 2005. 91.5 Community Radio for Northern Colorado. Image: Iron oxides in the stream bed of St. Kevin Gulch in Lake County Colorado, which receives AMD (Acid Mine Drainage) from the Griffin Mine.

KUNC program

Listen to the 4.5 minute program:

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D. McKnight: INSTAAR Biography

ANCIENT DIETS OF AUSTRALIAN BIRDS POINT TO BIG ECOSYSTEM CHANGES

Gifford Miller led an international team (INSTAAR, Carnegie Institution, Australian National University, Wollongong University, and Bates College) to discover that the diet of two flightless birds inhabiting Australia shifted soon after humans arrived ca. 50,000 years ago, coincident with a rapid and dramatic shift in the ecosystem's flora. Their discovery is the best evidence yet that early humans may have altered the continent's interior with fire, changing it from a mosaic of trees, shrubs, and grasses to the desert scrub evident today. The researchers used isotopic studies of nearly 1,500 eggshell fragments of fossilized emu and Genyornis dating back 140,000 years. The analyses, which pinpoint particular plant groups ingested by the birds, indicated that emus living before 50,000 years ago preferred nutritious grasses characteristic of milder temperatures and warm summer rains. After 45,000 years ago, the eggshell evidence showed emus successfully switched to a diet of mostly shrubs and trees characteristic of drier conditions. But Genyornis -- which also preferred the nutritious grass prior to 50,000 years ago -- failed to make the dietary switch and became extinct shortly after humans arrived. There were no significant swings in the continent's climate during that period, suggesting that humans indeed had a hand in the extinctions.

Published in the 8 July 2005 issue of Science. Image: Enlargement of a painting of extinct Genyornis courtesy Peter Trusler, from the book Wildlife of Gondwana by P. Vickers-Rich and T. Rich (Indiana University Press).

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Science Paper
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Science Commentary
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G. Miller: INSTAAR Biography

Katherine Suding (former INSTAAR postdoc; current assistant professor, Univ. of California, Irvine) led a team from eight universities in compiling data from previous and ongoing nitrogen-loading experiments on the alpine tundra of Niwot Ridge and in eight other ecosystems across North America. They found that rare plant species are six times more likely than abundant species to be lost due to nitrogen fertilization of soil. While nitrogen increases the production of most plants, an excess amount of it creates competition among plants for space that tends to drive rare plants out of existence, causing a loss of biodiversity. The team determined that other plant traits may put abundant plant species at risk in some settings: short height (short plants receive less sunlight in the midst of taller plants); the ability to convert atmospheric nitrogen, via bacteria, into a form that plants can use (the cost of supporting the bacteria hurts the plants); and a short life span (longer-living plants do not have to start the life cycle all over again). The teams' work on nearly a thousand plant species will help predict how patterns of plant diversity will decline as N availability continues to increase globally in terrestrial ecosystems due to human activities. The project was initiated through the Niwot Ridge Long-Term Ecological Research (LTER) site, administered by INSTAAR, including experiments by Tim Seastedt (INSTAAR) and Bill Bowman (INSTAAR). A subsequent larger effort was funded through the LTER network office. Additional INSTAAR contributions include data compilation assistance by Dan Liptzin. Publication of the research was highlighted in the 15 April issue of Science. Suding will return to INSTAAR this summer to continue research activities on Niwot Ridge and Colorado locales.

Much of the above text was taken from a Univ. of California Irvine news release. The paper was published in the March 22nd, 2005 issue of Proceedings of the National Academy of Sciences of the United States of America. Image: Alpine tundra photo by W. Bowman.

UCI News Release

PNAS Article

HUMANS HAVE DRASTIC EFFECT ON SEDIMENT TRANSFER TO WORLD'S COASTS

James Syvitski, Albert Kettner, and colleagues from the University of New Hampshire analyzed data from more than 4,000 rivers around the world that indicate humans are having profound and conflicting effects on the amount of sediment carried by rivers to coastal areas, with consequences for marine life and pollution control. The report found that humans are stirring up much more sediment than expected, about 2.3 billion metric tons annually, through regionally diverse patterns of agriculture and other soil erosion activities. However, manmade reservoirs are simultaneously reducing the flux of sediment reaching the world's coasts by about 1.4 billion metric tons per year. The net sediment transfer from an individual river to the ocean can greatly affect sensitive coastal zones, including nutrient balances, pollution levels, harbor dredging, coastal fish farms and coral reefs, coastal wetlands, and seagrass communities. In order to make their analysis, the team had to create a new computer model capable of globally consistent estimates of sediment flux near river mouths. The report was completed for the International Geosphere Biosphere Programme, a large-scale effort by scientists to study how humans have been and will continue to affect the entire planet.

Published in the 15 April 2005 Issue of Science. Image: River delta empties into McBeth Fjord, Baffin Island, Arctic Canada. Photo by James Syvitski.

Science commentary

Science article

CU Press Release

J. Syvitski: INSTAAR Biography

John Behrendt published an memoir of his work with the United States Antarctic Research Program in the early 1960s, when the Cold War was at its height and research on the ice sheet was risky. The Antarctic air squadron VX6 had an accident rate eight times that of U.S. Naval aviation in other parts of the world, and graduate students and young scientists like Behrendt received hazard pay for their work. In Behrendt's memoir we relive that era of scientific explorations with him. He describes two seasons on the ice in Operation Deep Freeze, leading field parties, conducting scientific research, and struggling against the elements. Behrendt led an over-snow geophysical-glaciological-geologic- geographic exploration party to the southern Antarctic Peninsula and to a mountain range that was eventually named for him in recognition of his work. Behrendt pioneered in aerogeophysical surveys over the Transantarctic Mountains and the West Antarctic Ice Sheet. In his reflections of the period from 1956 to 1962, he notes that time was closer to the eras of Ernest Schackleton (Endurance voyage, 1914) and Robert F. Scott's and Roald Amundsen's treks to the S. Pole (1911-12) than to the present. Readers who are fascinated with the twentieth century frontier of our shrinking planet will relish his adventurous account.

Image: Cover of The Ninth Circle

UNM Press

J. Behrendt: INSTAAR Biography

James W.C. White was named one of the most highly cited geoscientists by the ISI Web of Knowledge for the period 1981-1999. This select group comprised less than one-half of one percent of all publishing researchers -- truly an extraordinary accomplishment. The "highly cited" list at ISIHighlyCited.com will grow to include the top 250 preeminent individual researchers in each of 21 subject categories (life sciences, medicine, physical sciences, engineering and social sciences) who have demonstrated great influence in their field as measured by citations to their work--the intellectual debt acknowledged by their colleagues. One of the goals of the list is to identify individuals, departments and laboratories that have made fundamental contributions to the advancement of science and technology in recent decades.

Image: Portrait of James White.

J.W.C. White entry

HighlyCited.com

J. White: INSTAAR Biography

NOVEL TAXONOMIC WEB SITE ASSISTS ANTARCTIC ECOLOGICAL RESEARCH

Sarah Spaulding, Rhea Esposito, and David Lubinski led a team of scientists, graduate students and undergraduate students to develop a dynamic web database, "Antarctic Freshwater Diatoms", that combines ecological data collected over more than a decade in the McMurdo Dry Valleys region. The database takes a technologically novel approach by linking microscope images, scanning electron micrographs, original taxonomic descriptions, species geographic distributions, species assemblage data, maps, and permanent archives. Members of the research team are continually adding new data and images; no technical web knowledge is required. The interdisciplinary effort brought collaborators and students together from the University of Colorado, INSTAAR, University of Maine, CU Math-Bio Program, NSF Research Experience for Undergraduates (REU), and NSF Partnerships for Enhancing Expertise in Taxonomy (PEET). INSTAAR participants included Diane Mcknight and Chi Yang. The effort was principally funded by NSF's McMurdo Dry Valleys Long Term Ecological Research program (MCMLTER) and an NSF supplement to the Niwot Ridge LTER program to encourage collaboration among undergraduates in biological sciences and mathematics departments. Although just launched in late February 2005, the site is already serving as a model for regional taxonomic databases, as an effective way to recognize and communicate species endemism and biodiversity.

Image: McMurdo Dry Valleys Long Term Ecological Research program logo.

Antarctic Freshwater Diatoms

S. Spaulding: Personal Page

ARID AUSTRALIAN INTERIOR LINKED TO LANDSCAPE BURNING BY ANCIENT HUMANS

Gifford Miller and colleagues from the National Center for Atmospheric Research in Boulder and the Australian National University in Canberra used global climate model simulations to evaluate the atmospheric and meteorological conditions in Australia over time, as well as the sensitivity of the Australian monsoon to different vegetation and soil types. Their results suggest that landscape burning by ancient hunters and gatherers may have triggered the failure of the annual Australian Monsoon some 12,000 years ago, resulting in the desertification of the country's interior that is evident today. The study builds on previous field-based research of Miller's team; they found that dozens of giant animal species went extinct in Australia roughly 50,000 years ago, probably due to ecosystem changes caused by human burning. The new study indicates such burning may have eventually altered the flora enough to decrease the exchange of water vapor between the biosphere and atmosphere, causing the failure of the Australian Monsoon over the interior. The earliest human colonizers are believed to have arrived in Australia by sea from Indonesia about 50,000 years ago, using fire as a tool to hunt, clear paths, signal each other and promote the growth of certain plants. Fossil remains of browse-dependent birds and marsupials indicate the interior was made up of trees, shrubs and grasses rather than the desert scrub environment present today. Among other results, the research team found that a climate model simulating a forested Australia produced twice as much annual monsoon precipitation over the continental interior as the model simulating arid scrub conditions.

Published in the January 2005 Issue of Geology. Image: Taken from the cover of Geology, showing a prescribed burn in Australia. Photo by Gifford Miller.

CU Press Release

CNN

For those with access to the journal Geology:
abstract

G. Miller: INSTAAR Biography

Tim Seastedt won the 2005 Boulder County Pacesetter Environment award from the Daily Camera newspaper for his work on biological pest control of diffuse knapweed, an aggressive noxious weed that infests about 100,000 acres locally and 3 million acres in the West. Seastedt and his colleagues started studying knapweed population dynamics in 1997. Eventually they found several insect species that help eliminate the weed without the need for chemical pesticide treatments once every three years at an estimated cost of $20 to $40 per acre. The insect impacts were first noted in 2000 and became very obvious in 2001. Some of the insects have already dispersed across the Front Range of Colorado and others are available from the State of Colorado, Dept. of Agriculture, Biological Pest Control Section. The Daily Camera has presented Pacesetter awards since 1985 to recognize Boulder County residents who have made significant contributions to the community. The categories for 2005 include Lifetime Achievement, Youth, Quality of Life, Arts and Entertainment, Business, Science/ Medicine/Health, Community Service, Environment, and Education. A community reception and luncheon in honor of this year's winners was held at the Millennium Harvest House in Boulder on 19 January.

Image: Portrait of Tim Seastedt

NSF AWARDS INSTAAR $4.9 MILLION TO CONTINUE ALPINE ECOSYSTEM RESEARCH

The Niwot Ridge Long-Term Ecological Research project administered by INSTAAR scientists will continue for at least six more years as a result of a $4.9 million grant from the National Science Foundation. Located adjacent to INSTAAR's Mountain Research Station, Niwot Ridge is the only multidisciplinary, long-term alpine and sub-alpine study site on the continent. The study area encompasses several thousand acres of tundra, talus slopes, glacial lakes and wetlands straddling the Continental Divide 35 miles northwest of Boulder. The new grant will allow faculty and students to continue their studies of natural and human-caused changes that occur over decades and centuries. The eighteen principal investigators on the new NSF award are mostly from INSTAAR and other units at CU-Boulder; other participants are from Univ. of Montana, Univ. of Denver and the USGS. The leader of the project is Mark Williams of INSTAAR. Topics of study range from hydrology, geochemistry and nutrient transport to paleoecology, microbiology and ecology. The Niwot Ridge region has undergone recent climate warming as well as a four-fold increase in the deposition of atmospheric nitrogen in the past 20 years. The latter is believed to originate primarily from automobile, agricultural, ranching and industrial activity. These factors combined with other environmental changes have resulted in adverse affects on aquatic and terrestrial life in the sub-alpine and alpine environments. The NSF renewal grant for Niwot Ridge is the largest environmental sciences grant to CU-Boulder and helps the university to attract significant amounts of additional funding from other sources for high-mountain research.

Image: Niwot Ridge looking west. The flower in the foreground is Old-Man-of-the-Mountain (Hymenoxis grandiflora).  Photo by Bill Bowman.

CU Press Release

Niwot LTER

M. Williams: INSTAAR Biography