How mountain ranges get their shape

February 14, 2012 By Simone Ulmer

How mountain ranges get their shape

In the center of the picture the Allalinhorn with branches of the Feengletscher. Glaciers contribute significantly to shaping the relief of mountain ranges. Credit: Bild: Peter Rüegg / ETH Zürich

(PhysOrg.com) -- Tectonic, climate and the topography of the mountain ranges interact through a complex system of interactions and feedbacks. The nature and strength of these links are examined on the basis of data collection of 69 mountain ranges over the five continents.

Continental and oceanic crusts are "floating" on earth’s mantle. When two continental plates collide to each other, they shorten and thicken. Since continental crust has a lower density than mantle, it raises above the surrounding and form a mountain range. (rain, glaciers, wind, temperature variability etc.), coupled with the rate of crustal thickening are crucial to determine the erosion rate of the mountain range, as well as its overall shape.

Interaction of tectonic and ice

The nature of these interactions and feedbacks is examined by an international team lead by Jean-Daniel Champagnac (Ambizione Fellow) at the geological Institute of the ETH Zürich. This team recently published a study that constrain the strength of these interactions on the basis of measured tectonic, climatic and topographic values of different (69) mountain ranges widely distributed on the Earth surface. This study ran over six year in parallel to the main projects of the researchers involved. The goal was to examine the plausible laws of mountain building by data collection and statistical analyses.

For all the mountain ranges considered, the scientists determined specific quantitative variables. The climate was considered using the latitude (as a proxy for mean temperature and sun insolation), together with mean annual precipitation. The tectonic variable was defined by the shortening rate across each range, determined by GPS. As measures of the topography, the scientists used the averaged and maximum elevation above a base level previously defined, as well as relief calculated over different scale.

Latitude takes considerable impact

The statistical analyses confirm that the shape of result on the interaction between tectonics and climate. “That is trivial, but this is the first time that this is documented a global scale from natural data”, says Champagnac. Surprisingly, the importance of tectonic processes seems to be less important than so far assumed. Tectonic shortening is essential to thicken the crust, but climate exerts a stronger influence to shape the , according to this study. The relief is not sensitive to the average amount of precipitation, but to a combination of crustal shortening and latitude, where glaciations are more likely: small scale relief directly result on glacial imprint, whereas large scale relief result on crustal shortening.

The Alps are in a special situation, fully glaciated during glacial cycles, and almost fully deglaciated during the interglacial times: this produces very efficient glacial erosion and permanent reshaping of the landscape, by switching between glacial and fluvial erosion, says Champagnac.

Now the question arises whether tectonic processes were up to now overestimated.

More information: Champagnac, J. - D., et al: Tectonics, Climate, and Mountain Topography, J. Geophys. Res. (2012), doi:10.1029/2011JB008348 , in press.

Provided by ETH Zurich


Rank not rated yet
Relevant PhysicsForums posts

More news stories

Yale study concludes public apathy over climate change unrelated to science literacy

Are members of the public divided about climate change because they don't understand the science behind it? If Americans knew more basic science and were more proficient in technical reasoning, would public consensus match ...

Space & Earth / Environment

created 12 hours ago | popularity 4.8 / 5 (6) | comments 29 | with audio podcast

Land and sea species differ in climate change response: study

(Phys.org) -- Marine and terrestrial species will likely differ in their responses to climate warming, new research by Simon Fraser University and Australia’s University of Tasmania has found.

Space & Earth / Environment

created 10 hours ago | popularity 4 / 5 (5) | comments 9 | with audio podcast

10 million years needed to recover from mass extinction

It took some 10 million years for Earth to recover from the greatest mass extinction of all time, latest research has revealed.

Space & Earth / Earth Sciences

created 12 hours ago | popularity 4.2 / 5 (5) | comments 5 | with audio podcast

Sophisticated simulations predict future warming

The chances of our planet being hit by a global warming of 3 degrees Celsius by 2050 is as likely as it being hit by an increase of 1.4 degrees, new research shows. Presented in the journal Nature Geoscience, the British study ...

Space & Earth / Earth Sciences

created May 22, 2012 | popularity 3.8 / 5 (11) | comments 51

Kyoto Protocol architect 'frustrated' by climate dialogue

UN climate talks are going nowhere, as politicians dither or bicker while the pace of warming dangerously speeds up, one of the architects of the Kyoto Protocol told AFP.

Space & Earth / Environment

created May 23, 2012 | popularity 3.4 / 5 (8) | comments 44


Stunning image of smallest possible five-ringed structure

Scientists have created and imaged the smallest possible five-ringed structure – about 100,000 times thinner than a human hair – and you'll probably recognise its shape.

'Unzipped' carbon nanotubes could help energize fuel cells, batteries

Multi-walled carbon nanotubes riddled with defects and impurities on the outside could replace some of the expensive platinum catalysts used in fuel cells and metal-air batteries, according to scientists at ...

Change in developmental timing was crucial in the evolutionary shift from dinosaurs to birds: study

At first glance, it's hard to see how a common house sparrow and a Tyrannosaurus Rex might have anything in common. After all, one is a bird that weighs less than an ounce, and the other is a dinosaur that ...

Computer model used to pinpoint prime materials for efficient carbon capture

When power plants begin capturing their carbon emissions to reduce greenhouse gases – and to most in the electric power industry, it's a question of when, not if – it will be an expensive undertaking.

T cells 'hunt' parasites like animal predators seek prey, study shows

By pairing an intimate knowledge of immune-system function with a deep understanding of statistical physics, a cross-disciplinary team at the University of Pennsylvania has arrived at a surprising finding: T cells use a movement ...

Browser wars flare in mobile space

The browser wars are heating up again, but this time the fight is for dominance of the mobile Internet.