Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Formation of Lava Bubbles Offers New Insight into Seafloor Formation

19.11.2003


Side view of a collapsed lava pit on the East Pacific Rise near 9°50’N at a depth of 2,500 meters (about 8,000 feet). Two lava pillars in the center of the photo support a piece of the upper crust of the lava flow several inches thick.


Underside of a piece of lava from the East Pacific Rise showing drip structures or stalactites. The sample is about eight inches across, with individual lava drips of about one to two inches in length.
Photos ©Woods Hole Oceanographic Institution


Scientists studying the formation of the sea floor thousands of feet below the surface have a new theory for why there are so many holes and collapsed pits on the ocean bottom. In a recent article in the journal Nature, the researchers say the holes and pits of various sizes are probably formed by lava erupting onto the seafloor so quickly it traps water beneath it, forming bubbles of steam that eventually collapse as the water cools. The hardened crust then breaks, forming pock marks and glassy black plates of ocean crust with stalactites on their underside.

Findings by scientists at the Woods Hole Oceanographic Institution (WHOI) and colleagues may help explain the chemical differences between some seafloor lavas and increase understanding of deep-sea volcanic processes. The report also offers new insights into microbes living inside the ocean crust, an area known as the deep biosphere. No one has witnessed an undersea volcanic eruption, although researchers diving in the three-person submersible ALVIN have visited sites of very recent eruptions that were colonized almost immediately by exotic life forms.

Geologists Daniel Fornari and Deborah Smith of WHOI, along with lead author Michael Perfit of the University of Florida and colleagues from the University of Leeds in the United Kingdom, University of Hawaii and the US Geological Survey, report that up to now, scientists thought there was very little interaction between the very cold sea water at the ocean floor several miles deep and the molten lava that erupts to form new crust. Geologists didn’t think the lava, despite reaching temperatures well over 2,000 degrees Fahrenheit, could heat the seawater enough to form steam because of the intense pressure at such great depth.



Based on evidence from hardened lava samples collected during ALVIN dives at the East Pacific Rise off the Pacific coast of Mexico, they now believe that lava erupts so quickly onto the seafloor that it traps seawater under the flow, heats that water into steam to form bubbles that rise up through the lava flow to its top. These steam bubbles, much like the blobs in a lava lamp, are trapped under a relatively thin glassy outer crust.

Inside these bubbles, stalactites of molten lava drip from the crust and become coated with exotic minerals. WHOI Geomicrobiologist Katrina Edwards and graduate student Cara Santelli have noticed that many of the iron rich minerals observed in the lava samples through microscopic analysis are consistent with the iron oxide minerals that are formed in laboratory cultures. Edwards says this could suggest that sometime after formation and cooling, the glassy crusts are colonized and acted on by iron-oxidizing bacteria, and therefore support a subsurface biosphere.

Fornari says these new findings are important to understanding lava formation because the steam has the potential to change the chemistry of the lava, and the presence of bubbles of steam likely affects the way the lava flows across the sea floor. As a result of the steam interaction, lava flows may extend much farther along and across the crest of the mid-ocean ridge, a mountain range circling the earth like the seams on a baseball, forming a shell hundreds of feet thick covering more than half of the planet.

Woods Hole Oceanographic Institution (WHOI) is a private, independent marine research and engineering and higher education organization located in Falmouth, MA. Its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the ocean’s role in the changing global environment. Established in 1930 on a recommendation from the National Academy of Sciences, the Institution operates the US National Deep Submergence Facility that includes the deep-diving submersible ALVIN, a fleet of global ranging ships and smaller coastal vessels, and a variety of other tethered and autonomous underwater vehicles. WHOI is organized into five departments, interdisciplinary institutes and a marine policy center, and conducts a joint graduate education program with the Massachusetts Institute of Technology.

Shelley Dawicki | WHOI
Further information:
http://www.whoi.edu/media/LavaBubbles.html

More articles from Earth Sciences:

nachricht Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center

nachricht NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>