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Particle physics research sheds new light on possible ‘fifth force of nature’

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This picture depicts the long-range spin-spin interaction (blue wavy lines) in which the spin-sensitive detector on Earth’s surface interacts with geoelectrons (red dots) deep in Earth’s mantle. The arrows on the geoelectrons indicate their spin orientations, opposite that of Earth’s magnetic field lines (white arcs). (Credit: Illustration: Marc Airhart (University of Texas at Austin) and Steve Jacobsen (Northwestern University).)

In a breakthrough for the field of particle physics, Professor of Physics Larry Hunter and colleagues at Amherst College and The University of Texas at Austin have established new limits on what scientists call “long-range spin-spin interactions” between atomic particles. These interactions have been proposed by theoretical physicists but have not yet been seen. Their observation would constitute the discovery of a “fifth force of nature” (in addition to the four known fundamental forces: gravity, weak, strong and electromagnetic) and would suggest the existence of new particles, beyond those presently described by the Standard Model of particle physics….
Read more: http://www.sciencedaily.com/releases/2013/02/130221192736.htm

Written by physicsgg

February 22, 2013 at 1:19 pm

New clues to the early Solar System from ancient meteorites

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 In order to understand Earth’s earliest history–its formation from Solar System material into the present-day layering of metal core and mantle, and crust–scientists look to meteorites. New research from a team including Carnegie’s Doug Rumble and Liping Qin focuses on one particularly old type of meteorite called diogenites. These samples were examined using an array of techniques, including precise analysis of certain elements for important clues to some of the Solar System’s earliest chemical processing. Their work is published online July 22 by Nature Geoscience….
Read more at: phys.org

Written by physicsgg

July 22, 2012 at 6:17 pm

Posted in ASTRONOMY, GEOLOGY

Could GPS be used to predict earthquakes?

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Professor Kosuke Heki of Hokkaido University in Japan believes he has found a way to predict earthquakes.
Heki analyses GPS signals by measuring the TEC, or Total Electron Content, in the upper atmosphere. Whilst measuring how the TEC was disrupted by sound waves after the Tohoku earthquake of 2011, he discovered – quite by accident – that the TEC was also disrupted in the 40 or so minutes before it.
Going back through GPS records he has found similar correlations for other major earthquakes, a discovery that is being heralded as a major breakthrough in our understanding of earthquake phenomena.
See the relevant video here: www.bbc.co.uk

Written by physicsgg

March 26, 2012 at 7:10 pm

Posted in GEOLOGY

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Laguna del Maule

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In the Andean mountain range, stretching across the border between Chile and Argentina, lies a volcanic caldera named Laguna del Maule, roughly 15 by 25 kilometers (9 by 15 miles) across. Within the northern part of the caldera lies Maule Lake, which is surrounded by a complex volcanic landscape.

This perspective image is made from data acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite on April 9, 2003. ASTER produces images using infrared, red, and green wavelengths of light. In this image, vegetated areas range in color from red to pink, snow is white, water is black, and bare rock is earth-toned.

Laguna del Maule holds an assortment of volcanic features, including small stratovolcanoes, lava domes, and cinder cones. Some of the most prominent features surrounding Lake Maule are lava flows. Some of those lava flows protrude into the lake, looking a little like dough spreading under its own weight.

Volcanologists estimate that volcanoes at this site have been active over the past 10,000 years, but the date of the last eruption at Laguna del Maule is unknown.
Read more: earthobservatory.nasa.gov

Written by physicsgg

January 3, 2012 at 4:31 pm

Posted in GEOLOGY, SPACE

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‘New metal type’ at Earth’s core

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The precise chemistry of metals within the Earth's interior will dictate the nature of its magnetic field

The composition of the Earth’s core remains a mystery. Scientists know that the liquid outer core consists mainly of iron, but it is believed that small amounts of some other elements are present as well. Oxygen is the most abundant element in the planet, so it is not unreasonable to expect oxygen might be one of the dominant “light elements” in the core. However, new research from a team including Carnegie’s Yingwei Fei shows that oxygen does not have a major presence in the outer core. This has major implications for our understanding of the period when the Earth formed through the accretion of dust and clumps of matter. Their work is published Nov. 24 in Nature.

According to current models, in addition to large amounts of iron, the Earth’s liquid outer core contains small amounts of so-called light elements, possibly sulfur, oxygen, silicon, carbon, or hydrogen. In this research, Fei, from Carnegie’s Geophysical Laboratory, worked with Chinese colleagues, including lead author Haijun Huang from China’s Wuhan University of Technology, now a visiting scientist at Carnegie. The team provides new experimental data that narrow down the identity of the light elements present in Earth’s outer core.

With increasing depth inside the Earth, the pressure and heat also increase. As a result, materials act differently than they do on the surface. At Earth’s center are a liquid outer core and a solid inner core. The light elements are thought to play an important role in driving the convection of the liquid outer core, which generates the Earth’s magnetic field.

Scientists know the variations in density and speed of sound as a function of depth in the core from seismic observations, but to date it has been difficult to measure these properties in proposed iron alloys at core pressures and temperatures in the laboratory.

“We can’t sample the core directly, so we have to learn about it through improved laboratory experiments combined with modeling and seismic data,” Fei said.

High-speed impacts can generate shock waves that raise the temperature and pressure of materials simultaneously, leading to melting of materials at pressures corresponding to those in the outer core. The team carried out shock-wave experiments on core materials, mixtures of iron, sulfur, and oxygen. They shocked these materials to the liquid state and measured their density and speed of sound traveling through them under conditions directly comparable to those of the liquid outer core.

By comparing their data with observations, they conclude that oxygen cannot be a major light element component of the Earth’s outer core, because experiments on oxygen-rich materials do not align with geophysical observations. This supports recent models of core differentiation in early Earth under more ‘reduced’ (less oxidized) environments, leading to a core that is poor in oxygen.

“The research revealed a powerful way to decipher the identity of the light elements in the core. Further research should focus on the potential presence of elements such as silicon in the outer core,” Fei said.

carnegiescience.edu – bbc.co.uk

Written by physicsgg

December 20, 2011 at 9:07 pm

Posted in Chemistry, GEOLOGY

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Super-Powerful X-Ray Beam Will Probe the Center of the Earth

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Beamline Sample This image shows the heating of a catalyst sample in an "in situ" cell at actual operating conditions. The catalyst is studied using time-resolved X-ray absorption spectroscopy. A new beamline at the European Synchrotron Radiation Facility has a resolution of a few microseconds. ESRF

It is much easier to get to Mars than to get deep inside this planet, so for all our knowledge about things like earthquakes and the magnetic field, Earth’s interior is actually very poorly understood. To study how metals interact at the prodigious pressures within, scientists squeeze small particles in the lab and heat them up — but this is an inexact science and difficult to do. A newly revamped X-ray beam facility in Europe may be able to improve matters, and shed some light on just what is going on at the center of our planet.
The European Synchrotron Radiation Facility inaugurates its new ID24 beam today, in preparation for experiments next spring. It will enable scientists to exact extreme pressures and temperatures on metals, aiming to understand how they act at Earth’s core. It will also be able to study new chemical catalysts and battery technology, among other atomic reactions.
A synchrotron is a type of particle accelerator — the Tevatron is one — that can be used for a wide range of applications. One such application involves harnessing the accelerated particles’ electromagnetic radiation for scientific imaging. Synchrotron light sources use a series of magnetic fields to bend this radiation into different wavelengths of light. At ESRF, beamlines branch off from the particle acceleration ring to capture the particles’ (usually electrons) radiation. The new beamline, ID24, will enable incredibly fast X-ray absorption spectroscopy.
This works by firing an intense X-ray beam at a sample, and watching how atoms of the different elements inside the sample absorb the X-rays — it’s an active probe, monitoring its own experiments. The beamline has an array of germanium detectors that can take 1 million measurements per second, according to an ESRF news release. So scientists could take a small sample of iron, put it in the beamline, heat it to 10,000 degrees, and watch what happens. This would conceivably help scientists understand how iron behaves 1,500 miles beneath the surface of the Earth, and what are the melting points of other metals present in the mantle and core. This, in turn, could shed some light on things like Earth’s dynamo, which creates its magnetic field.
The ID24 beam is the first of eight new beamlines at ESRF, part of a $245 million (180 million Euro) upgrade.
http://www.popsci.com

Written by physicsgg

November 10, 2011 at 9:40 pm

Posted in GEOLOGY, NUCLEAR PHYSICS

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The Ozone Hole: Summer 2011

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NASA, NOAA Data Show Significant Antarctic Ozone Hole Remains
The Antarctic ozone hole, which yawns wide every Southern Hemisphere spring, reached its annual peak on Sept. 12. It stretched to 10.05 million square miles, the ninth largest ozone hole on record. Above the South Pole, the ozone hole reached its deepest point of the season on Oct. 9, tying this year for the 10th lowest in this 26-year record.

http://youtu.be/JZ1M4TJMUAc
NASA and the National Oceanic and Atmospheric Administration (NOAA) use balloon-borne instruments, ground-based instruments and satellites to monitor the annual Antarctic ozone hole, global levels of ozone in the stratosphere and the manmade chemicals that contribute to ozone depletion.

“The colder than average temperatures in the stratosphere this year caused a larger than average ozone hole,” said Paul Newman, chief scientist for atmospheres at NASA’s Goddard Space Flight Center in Greenbelt, Md. “Even though it was relatively large, the area of this year’s ozone hole was within the range we’d expect given the levels of manmade ozone-depleting chemicals that continue to persist in the atmosphere.”

The ozone layer helps protect the planet’s surface from harmful ultraviolet radiation. Ozone depletion results in more incoming radiation that can hit the surface, elevating the risk of skin cancer and other harmful effects.

“The manmade chemicals known to destroy ozone are slowly declining because of international action, but there are still large amounts of these chemicals doing damage,” said James Butler, director of NOAA’s Global Monitoring Division in Boulder, Colo.

In the Antarctic spring (August and September) the sun begins rising again after several months of darkness and polar-circling winds keep cold air trapped above the continent. Sunlight-sparked reactions involving ice clouds and manmade chemicals begin eating away at the ozone. Most years, the conditions for ozone depletion ease before early December when the seasonal hole closes.

Levels of most ozone-depleting chemicals in the atmosphere have been gradually declining as the result of the 1987 Montreal Protocol, an international treaty to protect the ozone layer. That international treaty caused the phase-out of ozone-depleting chemicals, which had been used widely in refrigeration, as solvents and in aerosol spray cans.

However, most of those chemicals remain in the atmosphere for decades. Global atmospheric computer models predict that stratospheric ozone could recover by midcentury, but the ozone hole in the Antarctic will likely persist one to two decades longer, according to the latest analysis in the 2010 Quadrennial Ozone Assessment issued by the World Meteorological Organization and United Nations Environment Programme, with co-authors from NASA and NOAA.

NASA currently measures ozone in the stratosphere with the Dutch-Finnish Ozone Monitoring Instrument, or OMI, on board the Aura satellite. OMI continues a NASA legacy of monitoring the ozone layer from space that dates back to 1972 with launch of the Nimbus-4 satellite. The instrument measured the 2011 ozone hole at its deepest at 95 Dobson units on Oct. 8 this year. This differs slightly from NOAA’s balloon-borne ozone observations from the South Pole (102 Dobson units) because OMI measures ozone across the entire Antarctic region.

That satellite-monitoring legacy will continue with the launch of NASA’s National Polar-orbiting Operational Environmental Satellite System Preparatory Project, known as NPP, on Oct. 28. The satellite will carry a new ozone-monitoring instrument, the Ozone Mapping and Profiler Suite. The instruments will provide more detailed daily, global ozone measurements than ever before to continue observing the ozone layer’s gradual recovery.

It will take a few years of averaging yearly lows in Antarctic ozone to discern evidence of recovery in ozone levels because seasonal cycles and other variable natural factors — from the temperature of the atmosphere to the stability of atmospheric layers — can make ozone levels dip and soar from day to day and year to year.

NOAA has been tracking ozone depletion around the globe, including the South Pole, from several perspectives. NOAA researchers have used balloons to loft instruments 18 miles into the atmosphere for more than 24 years to collect detailed profiles of ozone levels from the surface up. NOAA also tracks ozone with ground-based instruments and from space.
www.nasa.govl

Written by physicsgg

October 20, 2011 at 7:47 pm

Posted in GEOLOGY, meteorology

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Arty shot of moon crater with link to dinosaurs

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The sun rises over the central peak complex of the moon’s Tycho crater in this image captured by NASA’s Lunar Reconnaissance Orbiter on 10 June.
The spacecraft, which has been collecting detailed information about the lunar environment since June 2009, angled its orbit 65 degrees to the west to capture the image.
Located near the moon’s south pole, the Tycho crater is about 85 kilometres across and 4.7 kilometres from floor to rim. The mountain range shown here is about 15 kilometres wide, left to right (south-east to north-west in this view), with its peaks rising 2 kilometres above the crater floor.
Some simulations suggest the crater was created by an impact from a fragment of the same asteroid family that caused the Chicxulub crater on Earth, which wiped out the dinosaurs.

Chicxulub crater, is an ancient impact crater buried underneath the Yucatán Peninsula in Mexico

At 108 million years old, Tycho is one of the moon’s youngest impact craters, and bright lines of ejected material – not yet eroded by the space environment – can be seen in other images streaking the moon’s surface.
newscientist.com

Written by physicsgg

July 4, 2011 at 7:49 pm