Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How Productive are the Ore Factories in the Deep Sea?

24.04.2014

GEOMAR scientists demonstrate in "Nature" the supply routes of black smokers

Hydrothermal vents in the deep sea, the so-called "black smokers", are fascinating geological formations. They are home to unique ecosystems, but are also potential suppliers of raw materials for the future.


Visualization of a computer model. The pathways for the hydrothermal vents at a mid ocean ridge are marked clearly. The arrows indicate the movement of the Earths' plates at the plate boundaries. Graphics: J. Hasenclever, GEOMAR

They are driven by volcanic "power plants" in the seafloor and release amounts of energy that could meet the needs of a small town. But how exactly do they extract this energy from the volcanic rock?

Researchers at GEOMAR Helmholtz Centre for Ocean Research Kiel have now used computer simulations to understand the underground supply routes. The study is published in the international journal "Nature".

About ten years after the first moon landing, scientists on earth made a discovery that proved that our home planet still holds a lot of surprises in store for us. Looking through the portholes of the submersible ALVIN near the bottom of the Pacific Ocean in 1979, American scientists saw for the first time chimneys, several meters tall, from which black water at about 300 degrees and saturated with minerals shot out.

What we have found out since then: These "black smokers", also called hydrothermal vents, exist in all oceans. They occur along the boundaries of tectonic plates along the submarine volcanic chains. However, to date many details of these systems remain unexplained.
 
One question that has long and intensively been discussed in research is: Where and how deep does seawater penetrate into the seafloor to take up heat and minerals before it leaves the ocean floor at hydrothermal vents? This is of enormous importance for both, the cooling of the underwater volcanoes as well as for the amount of materials dissolved. Using a complex 3-D computer model, scientists at GEOMAR Helmholtz Centre for Ocean Research Kiel were now able to understand the paths of the water toward the black smokers. The study appears in the current issue of the world-renowned scientific journal "Nature".
 
In general, it is well known that seawater penetrates into the Earth's interior through cracks and crevices along the plate boundaries. The seawater is heated by the magma; the hot water rises again, leaches metals and other elements from the ground and is released as a black colored solution. "However, in detail it is somewhat unclear whether the water enters the ocean floor in the immediate vicinity of the vents and flows upward immediately, or whether it travels long distances underground before venting," explains Dr. Jörg Hasenclever from GEOMAR.
 
This question is not only important for the fundamental understanding of processes on our planet. It also has very practical implications. Some of the materials leached from the underground are deposited on the seabed and form ore deposits that may be of economically interest. There is a major debate, however, how large the resource potential of these deposits might be. "When we know which paths the water travels underground, we can better estimate the quantities of materials released by black smokers over thousands of years," says Hasenclever.
 
Hasenclever and his colleagues have used for the first time a high-resolution computer model of the seafloor to simulate a six kilometer long and deep, and 16 kilometer wide section of a mid-ocean ridge in the Pacific. Among the data used by the model was the heat distribution in the oceanic crust, which is known from seismic studies. In addition, the model also considered the permeability of the rock and the special physical properties of water.
 
The simulation required several weeks of computing time. The result: "There are actually two different flow paths – about half the water seeps in near the vents, where the ground is very warm. The other half seeps in at greater distances and migrates for kilometers through the seafloor before exiting years later." Thus, the current study partially confirmed results from a computer model, which were published in 2008 in the scientific journal "Science". "However, the colleagues back then were able to simulate only a much smaller region of the ocean floor and therefore identified only the short paths near the black smokers," says Hasenclever.
 
The current study is based on fundamental work on the modeling of the seafloor, which was conducted in the group of Professor Lars Rüpke within the framework of the Kiel Cluster of Excellence "The Future Ocean". It provides scientists worldwide with the basis for further investigations to see how much ore is actually on and in the seabed, and whether or not deep-sea mining on a large scale could ever become worthwhile. "So far, we only know the surface of the ore deposits at hydrothermal vents. Nobody knows exactly how much metal is really deposited there. All the discussions about the pros and cons of deep-sea ore mining are based on a very thin database," says co-author Prof. Dr. Colin Devey from GEOMAR. "We need to collect a lot more data on hydrothermal systems before we can make reliable statements".
 

Original publication:

Hasenclever, J., S.Theissen-Krah, L. H. Rüpke, J. P. Morgan, K. Iyer, S. Petersen, C. W. Devey: Hybrid shallow on-axis and deep off-axis hydrothermal circulation at fast-spreading ridges,Nature,http://dx.doi.org / 10.1038/nature13174     

High resolution images:
Visualization of a computer model. The pathways for the hydrothermal vents at a mid ocean ridge are marked clearly. The arrows indicate the movement of the Earths' plates at the plate boundaries. Graphics: J. Hasenclever, GEOMAR
Dr. Jörg Hasenclever in front of a visualization of his computer model. Photo: J. Steffen, GEOMAR 

Contact:
Dr. Jörg Hasenclever (GEOMAR,  RD 4 - Magmatic and Hydrothermal Systems), jhasenclever(at)geomar.de 
Jan Steffen (GEOMAR,  Communication & Media), Phone: +49-431 600-2811, jsteffen(at)geomar.de 

J. Steffen | Eurek Alert!
Further information:
http://www.geomar.de/index.php?id=4&no_cache=1&tx_ttnews%5btt_news%5d=1863&tx_ttnews%5bbackPid%5d=185&L=1

Further reports about: 3-D GEOMAR Ocean Phone circulation energy hydrothermal vents power plants underground

More articles from Earth Sciences:

nachricht In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>