Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Probing the Depths: Hebrew University, Swiss Researchers Analyze the Liquid That Lies Beneath the Surface

12.10.2005


While we generally think of water in nature as a cool liquid that we can see -- streams, lakes, oceans -- there is a great deal of “hot fluid” activity taking place far out of sight, deep within the earth, that influences what ultimately takes place on the surface, including the amount of rainfall and the buildup of new land mass.


Illustration shows the layers of the earth’s subsurface.



What exactly is the nature of that hidden fluid deep beneath the surface and what changes does it undergo as it seeks an ever-deeper venue?

Answer to these questions can be found in article in a recent issue of the journal Nature by Dr. Ronit Kessel of the Hebrew University’s Institute of Earth Sciences and her collaborators Prof. Max Schmidt, Prof. Peter Ulmer and Dr. Thomas Pettke from the Swiss Federal Institute of Technology, Zurich. In the article, the researchers report on a unique study in which fluids released from submerging earth plates at depths of 120-180 kilometers and temperatures between 700 and 1200 degrees centigrade are characterized for the first time.


Although the earth is principally a solid planet, water plays a major role in its evolution and differentiation. The presence of fluid affects the depth, temperature and composition of the melting that takes place deep within the bowels of the earth.

The surface of the earth is broken into large plates which move one relative to the other. When two plates collide, one plate can push the other downwards towards the center, carrying water deep into the mantle, which is the area between the earth’s crust and its core. As water enters the interior of the earth, it passes through water-rich (hydrous) minerals in the rock.

These hydrous minerals break down at depths of 50 to 200 kilometers, facilitating melting and ultimately leading to the super-heated volcanic zone. It is volcanic eruptions which regenerate our continental lithosphere (crust). Such volcanoes created, for example, the Aegean islands in southern Greece (the most famous of them is Santorini, which erupted in the 16th century B.C.E.), the “ring of fire” around the Pacific Ocean, and more.

These volcanoes eject many gases, for example carbon dioxide, to the atmosphere. These gases lead to thickening of the clouds and rain. As a result, water carried down to the interior of the earth influence precipitation on the surface. In addition, water at depth dissolves significant amounts of matter. The mobility of the water at depths also results in recycling other elements (including elements of economic value, such as chromium, nickel and vanadium) from place to place.

In order to characterize the fluids participating in every stage of the downward water cycle, the Hebrew University and Swiss researchers developed a novel experimental and analytical laboratory technique by which the composition of a fluid phase can be directly analyzed following high pressure and temperature experiments. Their work focused on determining how much water is stored in the down-going earth plate, how much dissolved matter it contains, and when these fluids are released from the plate and transferred to the mantle.

The results indicate that up to 180 kilometers deep, two kinds of fluids exist. One, at higher levels, is a fluid rich in water (70-90%) with only a little dissolved matter in it. This fluid exists at relatively low temperatures. The second component is a thick “hydrous melt,” rich in dissolved matter, which contains only 10-30% water. This component is a result of melting of the hydrous rocks at high temperature.

In their studies, the researchers found that different minerals display varying “preferences” for solubility, depending on the temperature at various depth levels.

Beyond a depth of 180 kilometers, only one kind of fluid exists, which is called supercritical liquid. A supercritical liquid is defined as a component which smoothly changes its character from fluid-like to a more solid, melt-like state, but is neither.

The researchers stress that it is essential to distinguish between melts, fluids and supercritical liquids in order to achieve a better understanding of the relationship between the down-going plate and volcanic eruptions and how matter is transferred in the earth interior.

Jerry Barach | alfa
Further information:
http://www.huji.ac.il

More articles from Earth Sciences:

nachricht NASA eyes Pineapple Express soaking California
24.02.2017 | NASA/Goddard Space Flight Center

nachricht 'Quartz' crystals at the Earth's core power its magnetic field
23.02.2017 | Tokyo Institute of Technology

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

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>