PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Glaciers help high-latitude mountains grow taller

Glaciers help high-latitude mountains grow taller
2010-09-15
(Press-News.org) Glaciers can help actively growing mountains become higher by protecting them from erosion, according to a University of Arizona-led research team.

The finding is contrary to the conventional view of glaciers as powerful agents of erosion that carve deep fjords and move massive amounts of sediment down mountains. Mountains grow when movements of the Earth's crust push the rocks up.

The research is the first to show that the erosion effect of glaciers – what has been dubbed the "glacial buzzsaw" – reverses on mountains in colder climates.

The researchers were surprised, said first author Stuart N. Thomson, a research scientist in the UA department of geosciences. "We were expecting to see the buzzsaw."

The team discovered the protective effects of glaciers by studying the Andes Mountains in the southernmost region of South America, known as Patagonia.

UA co-author Peter W. Reiners said, "It's been thought that glaciers limit the height of mountain ranges worldwide."

The key is climate. Glaciers atop mountains in temperate latitudes flow downhill, scouring away the surface of the mountain. Over millennia, such erosion can reduce the height and width of a mountain range by miles.

However in very cold climates such as the Patagonian Andes, rather than scraping away the surface of the mountain, the team found that glaciers protect the mountain top and sides from erosion.

The team dubs the action of the cold-climate glaciers "glacial armoring."

"Climate, especially through glaciers, has a really big impact on how big mountains get," said Reiners, a UA professor of geosciences.

"What we're seeing is that below certain latitudes, glacial buzzsaws clearly and efficiently operate, but south of about 45 degrees, it not only doesn't work – it has the opposite effect," he said. "The glaciers actually protect the surface and allow the mountains to grow higher."

He and his colleagues anticipate that glacial armoring also occurs on cold-climate mountains very far north, such as those in Alaska.

The team’s paper, “Glaciation as a destructive and constructive control on mountain building,” is scheduled for publication in the Sept. 16 issue of the journal Nature. Additional co‑authors are Mark T. Brandon and Nathaniel J. Wilson of Yale University in New Haven, Conn.; Jonathan H. Tomkin of the University of Illinois at Urbana‑Champaign; and Cristián Vásquez of the Universidad de Chile in Santiago. The National Science Foundation and the Chilean Fondecyt funded the work.

The Andes are the textbook example of actively growing mountains that are limited in height and size by glaciers, Thomson said. The Andes are actively being pushed higher by movements of the Earth's crust. However, if the glacial buzzsaw is active, the mountains also are ground down.

"We're trying to understand how mountains are built and destroyed," Thomson said. "Why are mountains high?"

In actively growing mountains, hot rocks from deep in the Earth are being thrust up. At the same time, erosion sands away the tops and sides of the mountains, bringing those once-hot rocks closer to surface. The speed at which the rocks cool indicates how rapidly the surface material above the rocks was removed by erosion.

To figure out how fast the glaciers had scoured the Andes, Thomson and his colleagues needed to analyze rocks now exposed on the mountains. The scientists sailed up glacially-cut fjords to the foot of remote glaciers and collected soccer-ball-sized rocks. The team collected rocks from latitude 38 degrees south to 56 degrees south, for a total of 146 samples.

The researchers analyzed the rocks in laboratories at the UA and at Yale University to determine what geologists call the "cooling age" of the rocks. The cooling age tells how fast the rock was exposed by erosion.

The researchers used two independent dating methods, apatite uranium-thorium-helium and fission-track dating, to determine cooling ages. Both methods showed the same result -- that the rocks cooled faster in the north and slower in the south. The slower the cooling, the more slowly the mountains are eroding.

Reiners said, "What corroborates this is that the mountains are higher in the south than in the north. Uplift is winning in the south, and the glacial buzzsaw is winning in the north."

The importance of climate in the formation of mountains is currently a matter of scientific debate, Thomson said.

The new finding indicates that climate plays a key role.

Said Thomson: "Climate determines the size of a mountain range – whether there is a glacial buzzsaw or glacial armoring."



INFORMATION:

Contact information:
Stuart Thomson
thomson@email.arizona.edu
Languages spoken: English, German
http://www.geo.arizona.edu/~thomson/

Peter Reiners
520-626-2236
reiners@email.arizona.edu
http://www.geo.arizona.edu/~reiners/

[Attachments] See images for this press release:
Glaciers help high-latitude mountains grow taller

ELSE PRESS RELEASES FROM THIS DATE:

Nature study shows how molecules escape from the nucleus

Nature study shows how molecules escape from the nucleus
2010-09-15
September 15, 2010 – (BRONX, NY) – By constructing a microscope apparatus that achieves resolution never before possible in living cells, researchers at Albert Einstein College of Medicine of Yeshiva University have illuminated the molecular interactions that occur during one of the most important "trips" in all of biology: the journey of individual messenger Ribonucleic acid (RNA) molecules from the nucleus into the cytoplasm (the area between the nucleus and cell membrane) so that proteins can be made. The results, published in the September 15 online edition of Nature, ...

Glaciers boost mountain growth in Andes

2010-09-15
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 ...

Nature publishes results of gene therapy treatment in phase 1/2 beta-thalassemia study

2010-09-15
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 ...

King's College London reveals promising techniques for extending the life of an organ transplant

2010-09-15
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. Although organ transplantation has been taking place for over 50 years, there are a number of significant challenges, such as a shortage of donor organs, maintaining the quality of an organ in transit, and the risk of organ rejection both immediately after transplant and in the following ...

Mount Sinai researchers develop database to help accelerate drug discovery

2010-09-15
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. Until ...

Discovery highlights promise of new immune system-based therapies

2010-09-15
BOSTON--A new focus on the immune system's ability to both unleash and restrain its attack on disease has led Dana-Farber Cancer Institute scientists to identify cells in mice that prevent the immune system from attacking the animals' own cells, protecting them from autoimmune diseases such as multiple sclerosis, type 1 diabetes, and lupus. The discovery, reported online on Sept. 16 by the journal Nature, may give scientists an effective way of operating the immune system's internal "control panel," leading to improved therapies for a variety of diseases – from vaccines ...

Home's electrical wiring acts as antenna to receive low-power sensor data

Homes electrical wiring acts as antenna to receive low-power sensor data
2010-09-15
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, ...

Robotic catheter could improve treatment of heart condition

Robotic catheter could improve treatment of heart condition
2010-09-15
VIDEO: 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... Click here for more information. 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 ...

Employee with higher level of emotional intelligence is more dedicated and satisfied at work

2010-09-15
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. The study, which Dr. Meisler carried out ...

Gene network reveals link between fats and heart disease signs

Gene network reveals link between fats and heart disease signs
2010-09-15
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 ...

LAST 30 PRESS RELEASES:

Reality check: making indoor smartphone-based augmented reality work

Overthinking what you said? It’s your ‘lizard brain’ talking to newer, advanced parts of your brain

Black men — including transit workers — are targets for aggression on public transportation, study shows

Troubling spike in severe pregnancy-related complications for all ages in Illinois

Alcohol use identified by UTHealth Houston researchers as most common predictor of escalated cannabis vaping among youths in Texas

Need a landing pad for helicopter parenting? Frame tasks as learning

New MUSC Hollings Cancer Center research shows how Golgi stress affects T-cells' tumor-fighting ability

#16to365: New resources for year-round activism to end gender-based violence and strengthen bodily autonomy for all

Earliest fish-trapping facility in Central America discovered in Maya lowlands

São Paulo to host School on Disordered Systems

New insights into sleep uncover key mechanisms related to cognitive function

USC announces strategic collaboration with Autobahn Labs to accelerate drug discovery

Detroit health professionals urge the community to act and address the dangers of antimicrobial resistance

3D-printing advance mitigates three defects simultaneously for failure-free metal parts 

Ancient hot water on Mars points to habitable past: Curtin study

In Patagonia, more snow could protect glaciers from melt — but only if we curb greenhouse gas emissions soon

Simplicity is key to understanding and achieving goals

Caste differentiation in ants

Nutrition that aligns with guidelines during pregnancy may be associated with better infant growth outcomes, NIH study finds

New technology points to unexpected uses for snoRNA

Racial and ethnic variation in survival in early-onset colorectal cancer

Disparities by race and urbanicity in online health care facility reviews

Exploring factors affecting workers' acquisition of exercise habits using machine learning approaches

Nano-patterned copper oxide sensor for ultra-low hydrogen detection

Maintaining bridge safer; Digital sensing-based monitoring system

A novel approach for the composition design of high-entropy fluorite oxides with low thermal conductivity

A groundbreaking new approach to treating chronic abdominal pain

ECOG-ACRIN appoints seven researchers to scientific committee leadership positions

New model of neuronal circuit provides insight on eye movement

Cooking up a breakthrough: Penn engineers refine lipid nanoparticles for better mRNA therapies

[Press-News.org] Glaciers help high-latitude mountains grow taller