Featured Research

from universities, journals, and other organizations

Hebrew University, Swiss Researchers Analyze Liquid That Lies Beneath The Surface

Date:
October 17, 2005
Source:
The Hebrew University of Jerusalem
Summary:
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 layers of earth’s subsurfaces.
Credit: Image courtesy of The Hebrew University of Jerusalem

What exactly is the nature of that hidden fluid deepbeneath the surface and what changes does it undergo as it seeks anever-deeper venue? Answer to these questions can be found in article ina recent issue of the journal Nature by Dr. Ronit Kessel of the HebrewUniversity's Institute of Earth Sciences and her collaborators Prof.Max Schmidt, Prof. Peter Ulmer and Dr. Thomas Pettke from the SwissFederal Institute of Technology, Zurich. In the article, theresearchers report on a unique study in which fluids released fromsubmerging earth plates at depths of 120-180 kilometers andtemperatures between 700 and 1200 degrees centigrade are characterizedfor the first time.

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

Thesurface of the earth is broken into large plates which move onerelative to the other. When two plates collide, one plate can push theother downwards towards the center, carrying water deep into themantle, which is the area between the earth's crust and its core. Aswater enters the interior of the earth, it passes through water-rich(hydrous) minerals in the rock.

These hydrous minerals break downat depths of 50 to 200 kilometers, facilitating melting and ultimatelyleading to the super-heated volcanic zone. It is volcanic eruptionswhich regenerate our continental lithosphere (crust). Such volcanoescreated, for example, the Aegean islands in southern Greece (the mostfamous of them is Santorini, which erupted in the 16th century B.C.E.),the "ring of fire" around the Pacific Ocean, and more.

Thesevolcanoes eject many gases, for example carbon dioxide, to theatmosphere. These gases lead to thickening of the clouds and rain. As aresult, water carried down to the interior of the earth influenceprecipitation on the surface. In addition, water at depth dissolvessignificant amounts of matter. The mobility of the water at depths alsoresults in recycling other elements (including elements of economicvalue, such as chromium, nickel and vanadium) from place to place.

Inorder to characterize the fluids participating in every stage of thedownward water cycle, the Hebrew University and Swiss researchersdeveloped a novel experimental and analytical laboratory technique bywhich the composition of a fluid phase can be directly analyzedfollowing high pressure and temperature experiments. Their work focusedon determining how much water is stored in the down-going earth plate,how much dissolved matter it contains, and when these fluids arereleased from the plate and transferred to the mantle.

Theresults indicate that up to 180 kilometers deep, two kinds of fluidsexist. One, at higher levels, is a fluid rich in water (70-90%) withonly a little dissolved matter in it. This fluid exists at relativelylow temperatures. The second component is a thick "hydrous melt," richin dissolved matter, which contains only 10-30% water. This componentis a result of melting of the hydrous rocks at high temperature.

Intheir studies, the researchers found that different minerals displayvarying "preferences" for solubility, depending on the temperature atvarious depth levels.

Beyond a depth of 180 kilometers, only onekind of fluid exists, which is called supercritical liquid. Asupercritical liquid is defined as a component which smoothly changesits character from fluid-like to a more solid, melt-like state, but isneither.

The researchers stress that it is essential todistinguish between melts, fluids and supercritical liquids in order toachieve a better understanding of the relationship between thedown-going plate and volcanic eruptions and how matter is transferredin the earth interior.


Story Source:

The above story is based on materials provided by The Hebrew University of Jerusalem. Note: Materials may be edited for content and length.


Cite This Page:

The Hebrew University of Jerusalem. "Hebrew University, Swiss Researchers Analyze Liquid That Lies Beneath The Surface." ScienceDaily. ScienceDaily, 17 October 2005. <www.sciencedaily.com/releases/2005/10/051016091311.htm>.
The Hebrew University of Jerusalem. (2005, October 17). Hebrew University, Swiss Researchers Analyze Liquid That Lies Beneath The Surface. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2005/10/051016091311.htm
The Hebrew University of Jerusalem. "Hebrew University, Swiss Researchers Analyze Liquid That Lies Beneath The Surface." ScienceDaily. www.sciencedaily.com/releases/2005/10/051016091311.htm (accessed September 17, 2014).

Share This



More Earth & Climate News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Isolated N. Korea Asks For International Help With Volcano

Isolated N. Korea Asks For International Help With Volcano

Newsy (Sep. 16, 2014) Mount Paektu volcano in North Korea is showing signs of life and there's not much known about it. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

    Technology News



    Save/Print:
    Share:

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile: iPhone Android Web
    Follow: Facebook Twitter Google+
    Subscribe: RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins