Changes in seismic velocity--changes in the speeds at which seismic waves move through the Earth's crust--have been identified during and after many earthquakes. But do these changes also happen before an earthquake, and could they be measured as a way to predict a quake on the way? The search for a clear and measurable pre-quake signal has been called "the holy grail of seismology."
Earth
The press release and paper noted below, publishing in the Bulletin of the Seismological Society of America, is strictly under embargo until 12:00 Noon Eastern Time US on August 2, 2012.
Now's the time to prepare for the heat waves, heavy rains and droughts that climate change will bring, says Stanford's Chris Field, a noted climate researcher.
Speaking Wednesday at a contentious U.S. Senate hearing on climate change, Stanford's Chris Field, an expert on climate change, offered a stark yet hopeful analogy.
Perhaps no other material is generating as much excitement in the electronics world as graphene, sheets of pure carbon just one atom thick through which electrons can race at nearly the speed of light – 100 times faster than they move through silicon. Superthin, superstrong, superflexible and superfast as an electrical conductor, graphene has been touted as a potential wonder material for a host of applications, starting with ultrafast transistors. For the vast potential of graphene to be fully realized, however, scientists must first learn more about what makes graphene so super.
Boulder, Colo., USA – Two Geology studies focus on debris flows and landslides, one from the point of view of alpine denudation and the other studying and quantifying hazards to human populations. Subjects of other studies include fossil microatolls and sea level; the potential rupture area for an earthquake offshore of the U.S. Pacific Northwest and British Columbia; paleoclimate; and the relationship between the formation of ore deposits and the growth cycle of microbial communities.
Earth's oceans, forests and other ecosystems continue to soak up about half the carbon dioxide emitted into the atmosphere by human activities, even as those emissions have increased, according to a study by University of Colorado and NOAA scientists to be published August 2 in the journal Nature.
The scientists analyzed 50 years of global carbon dioxide (CO2) measurements and found that the processes by which the planet's oceans and ecosystems absorb the greenhouse gas are not yet at capacity.
Despite sharp increases in carbon dioxide emissions by humans in recent decades that are warming the planet, Earth's vegetation and oceans continue to soak up about half of them, according to a surprising new study led by the University of Colorado Boulder.
Scientists have designed a simple system to study how electrons travel through energy barriers instead of over them.
This unusual behavior, called tunneling, is the particle equivalent of a person being able to walk through rather than over a mountain. The particle behavior is also one of the most common signs that everyday physics has broken down and quantum mechanics now controls the system.
Cambridge, Mass. - August 1, 2012 - In a vacuum, light travels so fast that it would circle the Earth more than seven times within the blink of an eye. When light propagates through matter, however, it slows by a factor typically less than 5. This factor, called the refractive index, is positive in naturally occurring materials, and it causes light to bend in a particular direction when it shines on, for example, water or glass.
FRANKFURT. Given the predicted rise in global temperatures in the coming decades, climate scientists are particularly interested in warm periods that occurred in the geological past. Knowledge of past episodes of global warmth can be used to better understand the relationship between climate change, variations in atmospheric carbon dioxide and the reaction of Earth's biosphere.
CORVALLIS, Ore. – A comprehensive analysis of the Cascadia Subduction Zone off the Pacific Northwest coast confirms that the region has had numerous earthquakes over the past 10,000 years, and suggests that the southern Oregon coast may be most vulnerable based on recurrence frequency.
Hot summer days cause in large cities very seldom great happiness among inhabitants. On those days the air is highly polluted with automobile and industrial emissions what makes breathing difficult and unhealthy. According to the latest calculations of Max Planck scientist Andrea Pozzer this scenario could become true for most of world population in 2050 if no counteractive measures are taken. Especially China, North India and the Middle East are expected to be affected by a drastic decrease in air quality.
Most of the world's population will be subject to degraded air quality in 2050 if man-made emissions continue as usual. In this 'business-as-usual' scenario, the average world citizen 40 years from now will experience similar air pollution to that of today's average East Asian citizen. These conclusions are those of a study published today in Atmospheric Chemistry and Physics, an Open Access journal of the European Geosciences Union (EGU).
So-called glass-formers are a class of highly viscous liquid materials that have the consistency of honey and turn into brittle glass once cooled to sufficiently low temperatures. Zhen Chen and his colleagues from Arizona State University, USA, have elucidated the behaviour of these materials as they are on the verge of turning into glass in an article about to be published in EPJ E¹.
With headlines proclaiming the discovery of the Higgs boson—the so-called God particle—particle physics has captured the imagination of the world, particularly among those who dwell on the nature of the cosmos. But this is only one puzzle seemingly solved in a universe of mysteries. In a recent paper in Physical Review Letters, Dartmouth physicists delve into another enigmatic particle.