Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Permafrost warming a challenge to Tibetian train route


Engineers constructing a new railroad across the vast, high-altitude Tibetan Plateau are using a surprisingly simple idea to fortify shifting frozen soils affected by climate warming, according to a University of Colorado at Boulder permafrost expert.

"The Qinghai-Xizang railroad is the most ambitious construction project in a permafrost region since the Trans-Alaska Pipeline," said CU-Boulder and National Snow and Ice Data Center researcher Tingjun Zhang. Zhang is working closely on the project with scientists at the Cold and Arid Regions Environmental and Engineering Research Institute in Lanzhou, China. "This is the first time engineers are primarily using crushed rock to insulate and fortify a structure against permafrost," he said.

Zhang will discuss the railroad project and the effects of widespread warming and thawing of frozen soils across the northern hemisphere at a press briefing in San Francisco Dec. 13 as part of the American Geophysical Union’s annual meeting. He will lead a panel of permafrost and climate experts from universities in the United States, Canada and the United Kingdom. "If current observations are indicative of long-term trends, we can anticipate major changes in permafrost conditions during the next century," Zhang said. "Permafrost is thawing in many regions, and it is significantly influencing landscapes and ecosystems."

One example is the Tibetan plateau, where the 695-mile Qinghai-Xizang railroad is due to be completed in 2007. More than 600 miles of track will be at altitudes of at least 13,000 feet above sea level, and 340 miles of track will lie across permafrost. Half of the permafrost area the tracks will cross is categorized as "high- temperature permafrost," Zhang said, meaning that the frozen soil is only 1 or 2 degrees Celsius below freezing. "The permafrost presents a challenge, because the climate of the area is predicted to become warmer during the next 50 to 100 years, and construction and train activity on the surface can also create heat and cause melting," Zhang said. "The shifting soils can ruin railroad tracks, roads and buildings. "In order to keep the track straight and the railroad foundation stable, engineers are using crushed rock to both insulate and cool the permafrost," he said.

Using on-site experiments and mathematical heat transfer modeling, engineers determined that a 2- to 3-foot layer of loose, medium sized rocks minimizes heat intake to the soil under railroad embankments during warmer months and promotes heat loss in winter. "The rock layer is so effective that it actually helps create a net cooling effect over time," Zhang said. One experiment detailed in Zhang’s presentation for the AGU meeting showed the permafrost under a railroad embankment was actually colder after a year of crushed rock insulation.

Though crushed rock permafrost insulation was first investigated as early as the 1960s, this is the first time a large-scale project is using the technique as one of its primary solutions, according to Zhang. The railroad also is using other means to cool and protect the soil, including shading, insulation and "passive heat pumps" comprised of piping that conducts heat from the ground and circulates cold air.

"Crushed rock is the most cost-effective method," Zhang said. "It’s mainly labor costs." Zhang is a researcher at the National Snow and Ice Data Center and the Cooperative Institute for Research in Environmental Sciences, both of which are affiliated with CU-Boulder. He earned bachelor’s and master’s degrees in physical geography from Lanzhou University in China. He holds master’s and doctoral degrees in geophysics from the University of Alaska, Fairbanks.

Zhang is currently the principal investigator on five frozen-ground research projects around the world, with funding from the National Science Foundation, NASA, the International Arctic Research Center at the University of Alaska-Fairbanks and the National Institute for Global Environmental Change at the U.S. Department of Energy.

Tingjun Zhang | EurekAlert!
Further information:

More articles from Earth Sciences:

nachricht Receding glaciers in Bolivia leave communities at risk
20.10.2016 | European Geosciences Union

nachricht UM researchers study vast carbon residue of ocean life
19.10.2016 | University of Miami Rosenstiel School of Marine & Atmospheric Science

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>