Featured Research

from universities, journals, and other organizations

Erosion has a point, and an edge

Date:
November 12, 2012
Source:
New York University
Summary:
Erosion caused by flowing water does not only smooth out objects, but can also form distinct shapes with sharp points and edges, researchers have found. Their findings reveal the unexpected ways that erosion can affect landscapes and artificial materials.

Erosion caused by flowing water does not only smooth out objects, but can also form distinct shapes with sharp points and edges, a team of NYU researchers has found. Their experiments showed water flow acts as a shearing force against objects, working them into specific shapes. The above illustrates how a cylinder, over time, was sculpted into a triangular shape.
Credit: New York University

Erosion caused by flowing water does not only smooth out objects, but can also form distinct shapes with sharp points and edges, a team of New York University researchers has found. Their findings, which appear in the latest edition of the journal the Proceedings of the National Academy of Sciences (PNAS), reveal the unexpected ways that erosion can affect landscapes and artificial materials.

Related Articles


The impact of erosion is widely recognized by environmentalists and geologists, but less clear is how nature's elements, notably water and air, work to shape land, rocks, and artificial structures, often resulting in unusual formations.

"The main focus of this study was to understand how and why erosion makes these funny shapes," explained Leif Ristroph, a post-doctoral researcher at NYU's Courant Institute of Mathematical Sciences and one of the study's co-authors.

To explore these questions, the researchers designed an experiment, conducted in the Courant Institute's Applied Mathematics Laboratory, to replicate natural erosion. In it, the researchers submerged clay -- shaped as balls or cylinders -- into a 15-ft. long water tunnel. The apparatus was designed to continuously generate a uniform flow of water, which would allow the researchers to observe how erosion shapes an entire object.

What they found was water flow acts as a shearing force -- not unlike a nail file -- against objects, working them into specific shapes. Starting from a clay ball, the flowing water sheared the sides away, producing a cone with a pointed face. Likewise, the clay cylinder was sculpted into a triangular shape. The researchers then sought to confirm these findings by replicating the experiment using a computer model. These results were consistent with the experimental findings, revealing in a computer simulation how the shape was maintained as the body eroded away.

"Water acts tangentially to the surface of objects and skims off material to create these unique shapes," explained Ristroph. "In a sense, it works as a sculptor to naturally mold materials into new forms."

The study's other co-authors were: Matthew Moore, a Courant post-doctoral fellow; Courant Professors Stephen Childress and Michael Shelley; and Jun Zhang, a professor at the Courant Institute and NYU's Department of Physics.

The research was supported by grants from the U.S. Department of Energy (DE-FG02-88ER25053) and the National Science Foundation (DMS-1103876, MRI-0821520).


Story Source:

The above story is based on materials provided by New York University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Leif Ristroph, Matthew N. J. Moore, Stephen Childress, Michael J. Shelley, and Jun Zhang. Sculpting of an erodible body by flowing water. PNAS, November 12, 2012 DOI: 10.1073/pnas.1212286109

Cite This Page:

New York University. "Erosion has a point, and an edge." ScienceDaily. ScienceDaily, 12 November 2012. <www.sciencedaily.com/releases/2012/11/121112171221.htm>.
New York University. (2012, November 12). Erosion has a point, and an edge. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2012/11/121112171221.htm
New York University. "Erosion has a point, and an edge." ScienceDaily. www.sciencedaily.com/releases/2012/11/121112171221.htm (accessed October 25, 2014).

Share This



More Earth & Climate News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Gets Climate Deal, UK PM Gets Knock

EU Gets Climate Deal, UK PM Gets Knock

Reuters - Business Video Online (Oct. 24, 2014) EU leaders achieve a show of unity by striking a compromise deal on carbon emissions. But David Cameron's bid to push back EU budget contributions gets a slap in the face as the European Commission demands an extra 2bn euros. David Pollard reports. Video provided by Reuters
Powered by NewsLook.com
Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Raw: Tornado Rips Roofs in Washington State

Raw: Tornado Rips Roofs in Washington State

AP (Oct. 24, 2014) A rare tornado ripped roofs off buildings, uprooted trees and shattered windows Thursday afternoon in the southwest Washington city of Longview, but there were no reports of injuries. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Fast-Moving Lava Headed For Town On Hawaii's Big Island

Fast-Moving Lava Headed For Town On Hawaii's Big Island

Newsy (Oct. 24, 2014) Lava from the Kilauea volcano on Hawaii's Big Island has accelerated as it travels toward a town called Pahoa. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins