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 Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft

nachricht How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>