Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists returning to field of eerie thermal spires

17.04.2003


The bizarre hydrothermal vent field discovered a little more than two years ago surprised scientists not only with vents that are the tallest ever seen – the one that’s 18 stories dwarfs most vents at other sites by at least 100 feet – but also because the fluids forming these vents are heated by seawater reacting with million-year-old mantle rocks, not by young volcanism.


A 3-foot-wide ledge or flange made of carbonate juts out from the side of a 160-foot chimney in the Lost City hydrothermal vent field. The chimney and flange are made of minerals dissolved in 160 F fluids that flow out of the seafloor and then precipitate when the fluids hit the icy cold seawater.
Photo credit: University of Washington



The remarkable Lost City hydrothermal vent field, so named partly because it sits on a seafloor mountain named the Atlantis Massif, was discovered in the middle of the Atlantic Ocean about 1,500 miles off the East Coast of the United States during an expedition that wasn’t even looking for hydrothermal vents.

Now the two scientists who were the first to travel in a submersible to the field after its serendipitous discovery Dec. 4, 2000, are leading a National Science Foundation-funded expedition to map and farther investigate the field. A Web site launched today at http://www.lostcity.washington.edu/ will follow the 32-day expedition that starts April 21.


The field is unlike any seen before, according to chief scientist Deborah Kelley, a University of Washington associate professor of oceanography, and co-chief scientist Jeff Karson, a Duke University professor of earth and ocean sciences. Both have visited fields of black-smoker hydrothermal vents that scientists have been studying since the 1970s.

Lost City is distinctive in part because the mighty 180-foot vent at the site, which scientists named Poseidon, is so much larger than previously studied black-smoker vents that mostly reach 80 feet or less. The tallest black-smoker chimney ever seen was a 135-foot vent off the coast of Washington (which toppled in recent years).

In contrast to black-smoker vents that are a darkly mottled mix of sulfide minerals, Lost City vents are nearly 100 percent carbonate, the same material as limestone in caves, and range in color from a beautiful clean white to cream or gray.

The differences are because hydrothermal venting – a process in which water circulates into the seafloor, gaining heat and chemicals until there is enough heat for the fluids to vent back into the ocean – doesn’t appear connected to volcanic activity and magma chambers. This is unlike most systems at mid-ocean ridge spreading centers. That’s where very young seafloor is created – often dramatically during volcanic eruptions – and vented water can be as hot as 700 F.

Lost City is nine miles from the nearest spreading center and sits on 1.5 million-year-old crust. Heat generated by chemical changes in the rocks appears to drive venting: seawater permeates deeply into the fractured surface of the mantle rocks where it transforms the mineral olivine into a new mineral, serpentine. The heat is not as great as that at volcanically active sites but is enough to power hydrothermal circulation and produce vent fluids of 105 to 170 F.

Lost City vent fluids support a community of microorganisms believed to live off the gases methane and hydrogen, both byproducts of serpentinization. This leads Kelley, Karson and others to speculate that life on this planet may have started in just such an environment, particularly since so much more mantle rock was exposed to seawater early in Earth’s history. And the same could be happening on other worlds.

The project includes scientists, engineers and students from the University of Washington, Duke University, Woods Hole Oceanographic Institution, U.S. National Oceanic and Atmospheric Administration, Switzerland’s Institute for Mineralogy and Petrology and Japan’s National Institute of Advanced Industrial Science and Technology.

The team leaves Barbados April 21 on board the Atlantis, operated by Woods Hole. It takes five days to reach the ocean above Lost City where researchers will use the submersible Alvin and an unmanned Autonomous Benthic Explorer.

Among those on the expedition will be lead pilot Pat Hickey, who took Kelley and Karson in the Alvin to see Lost City the day after it was first spotted during routine surveying using an unmanned, remotely operated vehicle. There was time for just a single dive before the expedition ended and bad weather began so scientists can only say the field is 300 feet by perhaps 1,700 feet and has roughly 30 vent structures. Since then the field has been visited by a U.S. film crew, which conducted no science, and a Russian group, which did limited sampling.

Work this month and next includes studying the waters above the field looking for clues to help find other Lost City fields and visiting a neighboring mountain that looks promising. Researchers also will grow and examine microorganisms recovered from the chimneys.

Sandra Hines | EurekAlert!
Further information:
http://www.washington.edu/
http://www.lostcity.washington.edu

More articles from Earth Sciences:

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

nachricht Canadian glaciers now major contributor to sea level change, UCI study shows
15.02.2017 | University of California - Irvine

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>