Geologists Use Particles from Galaxy's Far Reaches to Understand Processes at Earth's Surface

Scientists at the U.S. National Science Foundation and the European Commission of the European Union have announced a new initiative - called CRONUS, for cosmic-ray produced nuclide systematics - to measure cosmic rays from far-distant supernovas to time the history of the Earth's surface.

Image: Supernovae such as this one, named SN 1993J, give off blasts of cosmic rays that bombard the Earth and change the atomic make up of its surface rock. Researchers supported by the international CRONUS project will measure the effects of cosmic rays to determine the timing of ancient geologic events. The color scale represents the brightness of the radio emission detected by very large array radiotelescopes. Blue depicts the faintest emission; red depicts brightest. Credit: Image courtesy of NRAO/AUI and N. Bartel, M. Bietenholz, M. Rupen, et al.

Galactic explosions known as supernovas unleash torrents of fantastically energetic atomic particles. Billions of these cosmic rays impact Earth every year. The infinitesimal particles blast apart the atoms of Earth's atmosphere and rocks, changing them into new elements. Now, NSF has awarded $5.8 million over five years for geologists to measure the accumulated results of these atomic transmutations in rocks at Earth's surface.

Fred Phillips of the New Mexico Institute of Mining and Technology will coordinate the U.S. arm of the project, which includes 13 U.S. universities.

"The CRONUS initiative will benefit all disciplines in the Earth sciences," said Herman Zimmerman, director of NSF's division of earth sciences. Whether geomorphology, tectonics, volcanology, hydrology, geologic hazards, or paleoclimatology, he said, "Each needs an improved understanding of geochronology at the Earth's surface."

The European Union, through its Marie Curie Actions, has awarded 3.4 million Euro ($4.4 million) over four years for the project, a research-training network involving research teams in France, Germany, Netherlands, Slovakia, Switzerland the United Kingdom. Training of early stage and experienced researchers in the novel technique is an integral part of the European CRONUS effort to contribute to the mobility, exchange and training of high-quality European scientists.

Tibor Dunai, now at the Vrije Universiteit, Amsterdam, will coordinate the European arm. He will relocate to the University of Edinburgh in the fall of 2005.

"The ability to date changes in landscapes with cosmogenic nuclides has already revolutionized our understanding of Earth processes," said Dunai. "CRONUS will allow us to unlock the great potential this novel technique has, helping us to better understand the environment around us."

Powerful cosmic-ray particles penetrate only a few feet below the Earth's surface, so deeper rocks are shielded from the buildup of cosmic-ray transmutations. The number of new atoms produced by cosmic rays can thus show the amount of time passed since geological events such as earthquakes, landslides and glaciers. They can also reveal how fast Earth's surface changes from such forces as erosion by rivers.

"As scientists who use geochronology techniques in the course of their research," U.S. coordinator Phillips said. "We need to know exactly how cosmic rays are distributed on our planet's surface, taking into account variables like longitude, latitude, and elevation, as well as changes occurring over geologic time scales, such as periodic shifts in Earth's magnetic field."

Scientists affiliated with CRONUS will work to understand the fundamentals of cosmic-ray reactions so that they can routinely use them as methods for reconstructing and analyzing environment changes. When perfected, the new cosmic-ray methods will shed light on Earth's past climate cycles, changes in soil erosion, frequency of floods and landslides, and how weathering of rocks affects global warming and cooling.

Scientists from the United States and Europe will work together sampling rocks from key sites around the world, exposing elements to nuclear beams in high-energy accelerators, and counting cosmic-ray impacts with detectors aboard high-altitude aircraft. These results will all be synthesized in a broad-ranging effort to understand all aspects of the cosmic phenomenon.

"This is a way of bringing the projectiles of exploding stars down to very practical use on earth," said Phillips.

Source: NSF

Related stories:

Mars pioneers should stay there permanently, says Buzz Aldrin
The first astronauts sent to Mars should be prepared to spend the rest of their lives there, in the same way that European pioneers headed to America knowing they would not return home, says moonwalker Buzz Aldrin.
Cosmic eye sheds light on early galaxy formation
A Cosmic Eye has given scientists a unique insight into galaxy formation in the very early Universe. Using gravity from a foreground galaxy as a zoom lens the team was able to see a young star-forming galaxy in the distant Universe as it appeared only two billion years after the Big Bang.
The 'Magnificent 7' of European astroparticle physics unveiled to the world
Today Europeans presented to the world their strategy for the future of astroparticle physics. What is dark matter? What is the origin of cosmic rays? What is the role of violent cosmic processes? Can we detect gravitational waves?
Space: The not-so-final frontier
Of all environments, space must be the most hostile: It is freezing cold, close to absolute zero, there is a vacuum, so no oxygen, and the amount of lethal radiation from stars is very high. This is why humans need to be carefully protected when they enter this environment. New research by Ingemar Jönsson and colleagues published in the September 9 issue of Current Biology, a Cell Press journal, shows that some animals —the so-called tardigrades or 'water-bears'— are able to do away with space suits and can survive exposure to open-space vacuum, cold and radiation.
Physicists Rule Out the Production of Dangerous Black Holes at the LHC
(PhysOrg.com) -- On August 8, the world's largest particle accelerator, the Large Hadron Collider near Geneva, Switzerland, began the process of slowly throttling to full power. When its proton beams are circling at full speed and collisions begin, scientists from around the world will finally be able to start collecting data.
Could hadron collider devour the Earth?
Particle colliders creating black holes that could devour the Earth. Sounds like a great Hollywood script. But, according to UC Santa Barbara Physics Professor Steve Giddings, it's pure fiction.
Laser fluorescence could find life on Mars
A team of scientists from the United States and the United Kingdom has developed a technique using ultraviolet light to identify organic matter in soils that they say could be used to document the existence of life on Mars.
Astronomers use new model of dust in galaxies to remeasure the total energy output of stars in the universe
Anyone gazing up on a dark clear night is greeted by the spectacle of thousands of powerful fusion reactors - the stars. These balls of extremely hot gas are generating unimaginably large quantities of energy. Even the stars within a cube of "only" one light year on a side, taken at a random position in the universe, generate on average 40 quadrillion kilowatthours in one year.

News discussion:

Space & Earth science news