Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Historic Himalayan ice dams created huge lakes, mammoth floods

14.12.2004


Ice dams across the deepest gorge on Earth created some of the highest-elevation lakes in history. New research shows the most recent of these lakes, in the Himalaya Mountains of Tibet, broke through its ice barrier somewhere between 600 and 900 AD, causing massive torrents of water to pour through the Himalayas into India.



Geological evidence points to the existence of at least three lakes, and probably four, at various times in history when glacial ice from the Himalayas blocked the flow of the Tsangpo River in Tibet, said University of Washington geologist David Montgomery, a professor of Earth and space sciences.

Carbon dating shows the most recent lake, about 780 feet deep, burst through the ice dam between 1,100 and 1,400 years ago, rapidly draining some 50 cubic miles of water. The second lake, more than 2,200 feet deep, dates from about 10,000 years ago, and likely held more than 500 cubic miles of water. When that ice dam broke, it caused one of the greatest floods on Earth since the last ice age. The Tsangpo is the world’s highest river, with an average elevation of 13,000 feet, about 500 feet higher than South America’s Lake Titicaca, the highest lake. The Tsangpo flows to the eastern edge of Tibet before it turns south and plunges through a deep gorge into India, where it eventually becomes the Brahmaputra River and flows into the Bay of Bengal.


The new evidence indicates that several times in the Tsangpo’s history, moisture from strengthening monsoons built Himalayan glaciers into huge ice dams, stopping the river before it could leave Tibet. A group of researchers led by Montgomery found evidence of the resulting lakes in ledges carved into the sides of the Tsangpo gorge.

"It is possible that there would have been water close to the crest of the Himalayas," Montgomery said. "Not the high peaks but the passes, and they were probably blocked by ice too. It probably was like an ice-dammed ocean up there."

The group will present evidence of repeated damming and flooding of the Tsangpo gorge on Wednesday at the American Geophysical Union fall meeting in San Francisco. Co-presenters are Bernard Hallet, Alan Gillespie, Noah Finnegan, Matthew Kuharic, Amanda Henck, Alison Anders and Harvey Greenberg, all of the UW Department of Earth and Space Sciences; and Liu Yuping of the Chengdu Institute of Geology and Mineral Resources in Chengdu, China.

The smaller lake appears to have coincided with China’s Tang Dynasty and appears to have been the border between China and Tibet, Montgomery said. When the lake suddenly drained, it opened a large amount of rich farmland on the valley floor, farmland that today serves as the Tibetan breadbasket.

The Tsangpo River Gorge is considered some of the most spectacular terrain on Earth, as the river drops 7,800 feet (about 1.3 miles) in elevation over the course of about 125 miles. Parts of the gorge still have not been mapped because they are so rugged, possible evidence of the repeated sudden barrages of vast amounts of water unleashed by broken ice dams.

"You can carve a lot of beautiful deep valleys that way," Montgomery said. "To a geologist, that opens the question of, ’What is the role of these big floods? Are they responsible for carving that beautiful topography or are they merely second-bit players?’"

Vince Stricherz | EurekAlert!
Further information:
http://www.washington.edu

More articles from Earth Sciences:

nachricht Algorithm provides early warning system for tracking groundwater contamination
14.08.2018 | DOE/Lawrence Berkeley National Laboratory

nachricht Artificial Glaciers in Response to Climate Change?
10.08.2018 | Universität Heidelberg

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 interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>