CU News
News from the University of Colorado in Boulder.
CU Boulder study: Alaska’s iconic Columbia Glacier expected to stop retreating in 2020
Nov 26th
The wild and dramatic cascade of ice into the ocean from Alaska’s Columbia Glacier, an iconic glacier featured in the documentary “Chasing Ice” and one of the fastest moving glaciers in the world, will cease around 2020, according to a study by the University of Colorado Boulder.
A computer model predicts the retreat of the Columbia Glacier will stop when the glacier reaches a new stable position — roughly 15 miles upstream from the stable position it occupied prior to the 1980s. The team, headed by lead author William Colgan of the CU-Boulder headquartered Cooperative Institute for Research in Environmental Sciences, published its results today in The Cryosphere, an open access publication of the European Geophysical Union.
The Columbia Glacier is a large (425 square miles), multi-branched glacier in south-central Alaska that flows mostly south out of the Chugach Mountains to its tidewater terminus in Prince William Sound.
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Warming air temperatures have triggered an increase in the Columbia Glacier’s rate of iceberg calving, whereby large pieces of ice detach from the glacier and float into the ocean, according to Colgan. “Presently, the Columbia Glacier is calving about 2 cubic miles of icebergs into the ocean each year — that is over five times more freshwater than the entire state of Alaska uses annually,” he said. “It is astounding to watch.”
The imminent finish of the retreat, or recession of the front of the glacier, has surprised scientists and highlights the difficulties of trying to estimate future rates of sea level rise, Colgan said. “Many people are comfortable thinking of the glacier contribution to sea level rise as this nice predictable curve into the future, where every year there is a little more sea level rise, and we can model it out for 100 or 200 years,” Colgan said.
The team’s findings demonstrate otherwise, however. A single glacier’s contribution to sea level rise can “turn on” and “turn off” quite rapidly, over a couple of years, with the precise timing of the life cycle being difficult to forecast, he said. Presently, the majority of sea level rise comes from the global population of glaciers. Many of these glaciers are just starting to retreat, and some will soon cease to retreat.
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“The variable nature and speed of the life cycle among glaciers highlights difficulties in trying to accurately predict the amount of sea level rise that will occur in the decades to come,” Colgan said.
The Columbia Glacier was first documented in 1794 when it appeared to be stable with a length of 41 miles. During the 1980s it began a rapid retreat and by 1995 it was only about 36 miles long. By late 2000 it was about 34 miles long.
The loss of a massive area of the Columbia Glacier’s tongue has generated a tremendous number of icebergs since the 1980s. After the Exxon Valdez ran aground while avoiding a Columbia Glacier iceberg in 1989, significant resources were invested to understand its iceberg production. As a result, Columbia Glacier became one of the most well-documented tidewater glaciers in the world, providing a bank of observational data for scientists trying to understand how a tidewater glacier reacts to a warming climate.
Motivated by the compelling imagery of the Columbia Glacier’s retreat documented in the Extreme Ice Survey — James Balog’s collection of time-lapse photography of disappearing glaciers around the world — Colgan became curious as to how long the glacier would continue to retreat. To answer this question, the team of researchers created a flexible model of the Columbia Glacier to reproduce different criteria such as ice thickness and terminus extent.
The scientists then compared thousands of outputs from the computer model under different assumptions with the wealth of data that exists for the Columbia Glacier.
The batch of outputs that most accurately reproduced the well-documented history of retreat was run into the future to predict the changes the Columbia Glacier will most likely experience until the year 2100. The researchers found that around 2020 the terminus of the glacier will retreat into water that is sufficiently shallow to provide a stable position through 2100 by slowing the rate of iceberg production.
The speediness of the glacier’s retreat is due to the unique nature of tidewater glaciers, Colgan said. When warming temperatures melt the surface of a land glacier, the land glacier only loses its mass by run-off. But in tidewater glaciers, the changes in ice thickness resulting from surface melt can create striking changes in ice flow, triggering an additional dynamic process for retreat.
The dynamic response of the Columbia Glacier to the surface melt will continue until the glacier reaches its new stable position in 2020, at roughly 26 miles long. “Once the dynamic trigger had been pulled, it probably wouldn’t have mattered too much what happened to the surface melt — it was just going to continue retreating through the bedrock depression upstream of the pre-1980s terminus,” Colgan said.
Colgan next plans to attempt to use similar models to predict when the Greenland glaciers — currently the major contributors to sea level rise — will “turn off” and complete their retreats.
The future for the Columbia Glacier, however, looks bleak. “I think the hope was that once we saw climate change happening, we could act to prevent some irreversible consequences,” Colgan said, “but now we are only about eight years out from this retreat finishing — it is really sad. There is virtually no chance of the Columbia Glacier recovering its pre-retreat dimensions on human time-scales.”
The study was funded by NASA, and co-authors on the paper include W. Tad Pfeffer of CU-Boulder’s Institute of Arctic and Alpine Research, Harihar Rajaram of the CU-Boulder Department of Civil, Environmental, and Architectural Engineering, Waleed Abdalati of the National Aeronautic and Space Administration in Washington, D.C., and Balog of the Extreme Ice Survey in Boulder, Colo.
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CU study: New public gut bacteria study expected to reach around world
Nov 25th
Ever wondered who is living in your gut, and what they’re doing? The trillions of microbial partners in and on our bodies outnumber our own cells by as many as 10 to 1 and do all sorts of important jobs, from helping digest the food we eat this Thanksgiving to building up our immune systems.
In association with the Human Food Project, researchers at the University of Colorado Boulder along with researchers at other institutions around the world are launching a new open-access project known as “American Gut” in which participants can get involved in finding out what microbes are in their own guts and what they are doing in there.
The project builds on previous efforts, including the five-year, $173-million NIH-funded Human Microbiome Project, to characterize the microbes living in and on our bodies, said Associate Professor Rob Knight of CU-Boulder’s BioFrontiers Institute. But unlike other projects that have focused on carefully chosen test subjects with a few hundred people, this project allows the public to get involved and is encouraging tens of thousands of people to do so, Knight said.
“Galileo saw outer space through his telescope, and we want to see the inner space of your gut through modern genetics,” said Rob Dunn, a scientist at North Carolina State University and a collaborator on the project. The new project will be “crowd-funded” by individuals interested in learning more about their own gut bacteria and by others who simply want to contribute to the project, said Dunn.
“By combining the crowd-funding model with the open-access data analysis model that we pioneered with the Earth Microbiome Project, we can finally give anyone with an interest in his or her microbiome an opportunity to participate, whether by contributing samples or by looking at the data,” said Knight, also a Howard Hughes Medical Institute Early Career Scientist.
Public interest is immense, says the research team. 18,000 people have already signed up to receive more information by email about the project when it launches. “The American Gut project builds on the Human Microbiome Project by allowing anyone to participate, and will let the public join in the excitement of this new field,” said Lita Proctor, program director for the Human Microbiome Project. “We can expect this to lay the groundwork for all sorts of fascinating studies in the future, that others will in turn build on.”
The American Gut project is an opportunity for the “citizen scientists” working with team of leading researchers and labs throughout the United States to help shape a new way of understanding how diet and lifestyle may contribute to human health through each person’s suite of trillions of tiny microbes, say the researchers. A key aspect of the project is to understand how diet and lifestyle, whether by choice — like athletes or vegetarians — or by necessity, including those suffering from particular autoimmune diseases or who have food allergies, affect peoples’ microbial makeup, said Knight.
“This will be the first project of its kind that might be able to address this question at such a large scale,” said Jeff Leach, founder of the Human Food Project and co-founder of American Gut. The gut microbiome has been linked to many diseases, including obesity, cancer, and inflammatory bowel disease — all of which are much more common in Western populations, he said.
“We should start thinking about diets not only from the perspective of what we should eat, but what we should be feeding our entire gut microbial systems,” said Leach. A key aspect of the project is to integrate studies of Americans of all shapes and sizes with studies of people living more traditional lifestyles in Africa, South America and elsewhere, he said.
The steep decline in the cost of DNA sequencing and recent advances in computational techniques allow for the analysis of microbial genomes orders of magnitude cheaper than was possible only a few years ago, said Knight. Sequencing is now getting cheap enough — participants who donate $99 or more can expect to get tens of thousands of sequences from microbes in their gut — that participants can include their families and even their pets, Knight said.
Doctoral student Daniel McDonald is one of several CU-Boulder students who will be involved in the effort. “I am excited to have the opportunity to develop new computational tools in order to further explore this frontier,” said McDonald, who is in the Interdisciplinary Quantitative Biology program at the BioFrontiers Institute.
“I am pleased to participate in this pioneering effort that marries the vast interest of the public in science with questions that are worth answering about human health and nutrition,” said Martin Blaser, chair of the Department of Medicine and professor of microbiology at New York University. “Through this consortium, the technical and intellectual resources are there to lead to important new knowledge.”
The project will seek to build on a growing canine and feline database as well. “The majority of data we currently have on the dog and cat microbiomes has come from a handful of small studies in research or clinically ill animals,” said Associate Professor Kelly Swanson of the Department of Animal Sciences and Division of Nutritional Sciences at the University of Illinois at Urbana-Champaign. “This study will apply the technology to free-living pets, where diet, genetics, and living environment are quite different from household to household.
“This research may identify important trends not possible with lab-based studies, and help guide us on how to feed our pets in the future,” said Swanson.
The backdrop to the project is the radical decline in the cost of DNA sequencing, which allows analysis of microbial genomes orders of magnitude cheaper than was possible only a few years ago, and recent advances in computational techniques. Participants in the project include many of the key players in the Human Microbiome Project and research facilities around the world.
To learn more about participating in or contributing to the project visit https://www.indiegogo.com/americangut. For a list of additional collaborators on the project visithttp://humanfoodproject.com/the-people/collaborators/.
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CU police: Suspect in rash of thefts is arrested
Nov 20th
Raymond Webster Hamilton, wanted for questioning in a pattern of recent wallet thefts at three university campuses, is in custody.
Hamilton, 26, of Denver, is a suspect wanted in connection with the theft of an iPad at the University of Colorado Boulder over the summer. He is also a person of interest in at least 23 cases of wallet and laptop thefts at CU-Boulder, CU Anschutz Medical Campus and the Colorado School of Mines.
State parole officers arrested Hamilton in Denver on Monday, November 19, 2012. He declined to speak to a CU-Boulder police detective on scene. The investigation into the wallet and laptop thefts is ongoing. Hamilton was booked into the Denver County Downtown Detention Center on charges of providing false information to a pawn broker, three fugitive holds and a parole violation. He is being held without bond.
“We thank the media for their assistance in publicizing these cases, and we thank the public for their tips that led to this arrest,” said CU-Boulder Police spokesman Ryan Huff. “At the same time, we remind the campus community that they need to stay vigilant in protecting their valuable items.”
CU-Boulder police worked with Lakewood police to obtain an arrest warrant for Hamilton. He is not a CU student. The following is a chronology of recent thefts at the three universities:
- Hamilton pawned an iPad just hours after it was stolen from a CU-Boulder Visual Arts Complex office on July 25, 2012. As a result of that case, Hamilton had an active arrest warrant for pawning stolen property (a Class 6 felony) to a Lakewood pawn broker.
- On Oct. 17, 2012, someone stole five wallets and a laptop from CU-Boulder academic building offices and the University Memorial Center.
- On Oct. 19, 2012, someone stole three wallets from offices at the Colorado School of Mines. A CSM Police Department investigation determined that Hamilton is a person of interest in at least one of those cases.
- On Oct. 24, 2012, someone stole wallets and purses from 14 offices at CU Anschutz Medical Campus. Surveillance video of the suspect resembles Hamilton.
From Oct. 2 to Oct. 20, 2012, UCPD recorded 15 cases of a suspect or suspects stealing laptops and wallets from common areas or unlocked offices. For a Google Map with dates, locations and stolen items, see http://bit.ly/Oct2012CUthefts.
The CU Police Department reminds the campus community to keep lockers and offices secured when unattended. In common areas, such as dining facilities, libraries or the University Memorial Center, never leave laptops, mobile phones or other valuable items unattended – even if just stepping away for a few minutes. For more crime prevention tips, see http://police.colorado.edu/crime-prevention-and-safety.
