(Press-News.org) New Haven, Conn.—Glaciers have carved some of the planet's most dramatic landscapes, from Yosemite National Park to the Himalayas. Now geologists have discovered that glaciers can do more than erode mountain peaks and shape valleys—they can actually encourage mountain growth.
A new study, which appears in the September 16 issue of Nature, found that glaciers in the southern reaches of the Patagonian Andes have acted as a kind of protective shield throughout the mountain range's 25-million-year history, providing the first evidence to contradict the widely held belief that glaciers inhibit mountain growth.
Until now, scientists thought that glaciers ubiquitously erode mountains, slowing their growth once the mountain peak reaches above the snowline. Above this elevation, where glaciers remain permanently frozen, scientists believed that the masses of ice carve away at the mountain face as they slide down its surface—an idea known as the "buzzsaw theory."
At the relatively low elevations found in the southern Andes, scientists expected the buzzsaw effect would have had a major impact on the mountains throughout the 25 million years they've been building, said Mark Brandon, a Yale geologist and an author of the new study.
Instead, the team found just the opposite. They measured the ages of rock samples from a vast track of the Patagonian Andes and discovered that at higher southern latitudes—where the mountains are at lower elevation and so the glacial buzzsaw should have a bigger impact—the rock was older than expected, meaning erosion has been taking place at a much slower rate than previously thought.
Rather than slicing away at the mountain peaks, the scientists found that the glaciers instead seem to have helped the mountains grow. "The glaciers act like armor to protect the uplifting mountains from erosion, allowing them to reach heights well above those predicted by the glacial buzzsaw theory," Brandon said.
Despite the lower elevations found in the Patagonian Andes, the glaciers remain cold enough that their bases are frozen and stuck to the mountain surface, Brandon said. Whereas warmer glaciers melt at their base and slide down the mountain, these colder glaciers appear to have provided an icy shield.
The new finding presents the first evidence to contradict the glacial buzzsaw theory, Brandon said—a theory that has proven difficult to test on large scales and over geological time scales.
Next, the team will try to use the results to calibrate a global erosion model to understand how climate affects the mountain building process.
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Other authors of the paper include Stuart Thomson and Peter Reiners (University of Arizona); Jonathan Tomkin (University of Illinois); Cristián Vásquez (Universidad de Chile); and Nathaniel Wilson (Yale University).
Citation: DOI: 10.1038/nature09365
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Cambridge, Mass., September 15, 2010 – bluebird bio (formerly Genetix Pharmaceuticals Inc.) an emerging leader in the development of innovative gene therapies for severe genetic disorders, today announced publication in the journal Nature of its promising Phase 1/2 data highlighting positive results of LentiGlobin™ gene therapy treatment in a young adult with severe beta-thalassemia, a blood disorder that is one of the most frequent inherited diseases.
The patient, who had been transfusion dependent since early childhood, has become transfusion independent for the past ...
Experts from the Medical Research Council (MRC) Centre for Transplantation at King's College London, based at Guy's Hospital, have revealed exciting new scientific developments for people with an organ transplant, intended to help prevent rejection of the new organ and extend its life.
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Researchers from Mount Sinai School of Medicine have developed a new computational method that will help streamline the analysis of gene expression experiments and provide scientists with a better mechanistic understanding of the differences between diseased and normal cells. The new database and software, called ChIP Enrichment Analysis (ChEA), will revolutionize how researchers identify drug targets and biomarkers. Researchers can find the tool online at http://amp.pharm.mssm.edu/lib/chea.jsp. The data are published in the September 15th issue of Bioinformatics.
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If these walls had ears, they might tell a homeowner some interesting things. Like when water is dripping into an attic crawl space, or where an open window is letting hot air escape during winter.
The walls do have ears, thanks to a device that uses a home's electrical wiring as a giant antenna. Sensors developed by researchers at the University of Washington and the Georgia Institute of Technology use residential wiring to transmit information to and from almost anywhere in the home, allowing for wireless sensors that run for decades on a single watch battery. The technology, ...
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NC State's Dr. Greg Buckner has developed a robotic catheter that is significantly more maneuverable than existing devices, which could lead to reduced operating times for patients undergoing heart surgery...
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Atrial fibrillation is a heart disorder that affects more than two million Americans, and is considered a key contributor to blood clots and stroke. Now researchers from North Carolina State University are developing a new ...
Employees with a high level of emotional intelligence are more dedicated and satisfied at work, compared to other employees. This has been shown in a new study from the University of Haifa. "This study has shown that employees with a higher level of emotional intelligence are assets to their organization. I believe it will not be long before emotional intelligence is incorporated in employee screening and training processes and in employee assessment and promotion decisions" stated Dr. Galit Meisler, who conducted the research.
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A gene network behind hardening of the arteries and coronary heart disease has been identified by a team of scientists from Australia, Europe and the United Kingdom. Their findings expose potential targets for the treatment of heart disease.
Dr Michael Inouye, a postdoctoral fellow at the Walter and Eliza Hall Institute in Melbourne, Australia, began the study at the Wellcome Trust Sanger Institute in the UK and completed it earlier this year at the Walter and Eliza Hall Institute. Researchers from Finland's National Institute for Health and Welfare, the University of ...
Australian researchers are embarking on a study of mums in the United Kingdom to discover if "guilt-tripping women" into breastfeeding is effective in persuading them to opt for breast over bottle.
Queensland University of Technology (QUT) is a recognised leader in breastfeeding research and has already undertaken a study in Australia and the US.
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Scientists at the University of East Anglia (UEA) are launching a groundbreaking new project to investigate the benefits of broccoli in the fight against osteoarthritis.
Initial laboratory research at UEA has found that a compound in broccoli called sulforaphane blocks the enzymes that cause joint destruction in osteoarthritis – the most common form of arthritis.
Broccoli has previously been associated with reduced cancer risk but this is the first major study into its effects on joint health.
With funding from both Arthritis Research UK and the Diet and Health ...
