The May 12 earthquake that rocked Sichuan Province in China was the first there in recorded history and unexpected in its magnitude. Now a team of geoscientists is looking at the potential for future earthquakes due to earthquake-induced changes in stress.
Around the world, earthquakes like the one in China are associated with triggered aftershocks that are very large. In 1999, a 7.1 earthquake in Duzce, Turkey, followed a 7.4 magnitude earthquake in Izmit, Turkey. In 2004, an 8.7 magnitude earthquake struck three months after the Sumatra Andaman earthquake of magnitude 9.2. While analysis of the Turkish earthquakes was not timely enough to shed light on the second earthquake there, the researchers believe that information on the Sumatra Andaman earthquake did illuminate the situation.
For the May 12 earthquake, the researchers performed analysis of co-seismic stress transfer onto Sichuan basin faults using broad ranges because at this time, exact values for all the various factors are unknown. The researchers report in today's (July 6) advanced online edition of Nature that "this approach enables rapid mapping of faults with heightened rupture likelihood."
Science & Technology
How do you weigh the biggest black holes in the universe? One answer now comes from a completely new and independent technique that astronomers have developed using data from NASA's Chandra X-ray Observatory.
By measuring a peak in the temperature of hot gas in the center of the giant elliptical galaxy NGC 4649, scientists have determined the mass of the galaxy's supermassive black hole. The method, applied for the first time, gives results that are consistent with a traditional technique.
Astronomers have been seeking out different, independent ways of precisely weighing the largest supermassive black holes, that is, those that are billions of times more massive than the Sun. Until now, methods based on observations of the motions of stars or of gas in a disk near such large black holes had been used.
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| ©X-ray (NASA/CXC/Univ. of California Irvine/P.Humphrey et al.); Optical (NASA/STScI) |
| A composite image from NASA's Chandra X-ray Observatory (shown in purple) and Hubble Space Telescope (blue) shows the giant elliptical galaxy NGC 4649. By applying a new technique, scientists used Chandra data to measure the black hole at its center to be about 3.4 billion times more massive than the Sun. The value from this X-ray technique is consistent with a more traditional method using the motions of stars near the black hole. NGC 4649 is now one of only a handful of galaxies for which the mass of a supermassive black hole has been measured with two different methods. |
By measuring a peak in the temperature of hot gas in the center of the giant elliptical galaxy NGC 4649, scientists have determined the mass of the galaxy's supermassive black hole. The method, applied for the first time, gives results that are consistent with a traditional technique.
Astronomers have been seeking out different, independent ways of precisely weighing the largest supermassive black holes, that is, those that are billions of times more massive than the Sun. Until now, methods based on observations of the motions of stars or of gas in a disk near such large black holes had been used.
Ever since Victorian astronomers pointed their telescopes towards Mars and wrongly believed they had discovered canals, mankind has been obsessed by the red planet.
Now these astonishing new images - captured by a European spacecraft in orbit around Mars - are helping to fuel that fascination.
They show in astonishing detail a network of giant valleys, vast plains and towering waterfalls carved into the surface of our neighbouring planet, millions of miles away.
Now these astonishing new images - captured by a European spacecraft in orbit around Mars - are helping to fuel that fascination.
They show in astonishing detail a network of giant valleys, vast plains and towering waterfalls carved into the surface of our neighbouring planet, millions of miles away.
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| ©Reuters |
| Spectacular: A view of Echus Chasma, one of the largest water source regions on Mars, showing a network of valleys |
The scientists have stopped holding their breath. Three weeks after the launch of the Gamma-ray Large Area Space Telescope (GLAST), researchers from Stanford University, the Stanford Linear Accelerator Center and elsewhere have shaken awake the scientific instruments aboard their $690 million satellite, 350 miles above Earth, for the first time. And everything's working.
On the Large Area Telescope, the principal instrument on GLAST, the computers booted up properly, the 16 gamma-ray detectors came to life, and communications checked out well. The observatory's navigation system is following directions from the ground to turn toward interesting objects.
On the Large Area Telescope, the principal instrument on GLAST, the computers booted up properly, the 16 gamma-ray detectors came to life, and communications checked out well. The observatory's navigation system is following directions from the ground to turn toward interesting objects.
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| ©Getty Images |
| Jodrell Bank in Cheshire is home to the Lovell Telescope |
The future of Jodrell Bank, one of the world's leading radio astronomy centres, is secure according to the site's owner, Manchester University.
Jodrell's existence had been in doubt because of uncertainty over where money would come from to finish and run its key new project, the eMerlin network.
But the university says funding for the network, which ties together radio dishes across the UK, is now in place.
Jodrell has made many key discoveries and even tracked the Moon landings.
The observatory, famous for its giant Lovell antenna, has been caught up in the budgetary difficulties of the Science and Technology Facilities Council (STFC), which oversees UK physics and astronomy.
Some 40,000 years ago, Cro-Magnons -- the first people who had a skeleton that looked anatomically modern -- entered Europe, coming from Africa. A group of geneticists, coordinated by Guido Barbujani and David Caramelli of the Universities of Ferrara and Florence, shows that a Cro-Magnoid individual who lived in Southern Italy 28,000 years ago was a modern European, genetically as well as anatomically.
The Cro-Magnoid people long coexisted in Europe with other humans, the Neandertals, whose anatomy and DNA were clearly different from ours. However, obtaining a reliable sequence of Cro-Magnoid DNA was technically challenging.
"The risk in the study of ancient individuals is to attribute to the fossil specimen the DNA left there by archaeologists or biologists who manipulated it," Barbujani says. "To avoid that, we followed all phases of the retrieval of the fossil bones and typed the DNA sequences of all people who had any contacts with them."
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| ©David Caramelli et al. |
| Tibia fragment. DNA was extracted from this fragment and from skull splinters, and all extracts yielded the same HVR I sequence. |
The Cro-Magnoid people long coexisted in Europe with other humans, the Neandertals, whose anatomy and DNA were clearly different from ours. However, obtaining a reliable sequence of Cro-Magnoid DNA was technically challenging.
"The risk in the study of ancient individuals is to attribute to the fossil specimen the DNA left there by archaeologists or biologists who manipulated it," Barbujani says. "To avoid that, we followed all phases of the retrieval of the fossil bones and typed the DNA sequences of all people who had any contacts with them."
One of the oldest arguments against anarchism is that it is impractical, that without central authority to keep the peons in line any large project will dissolve into chaos and disorder. Yet the open source software movement provides modern day proof that anarchism works, even when not conducted by anarchists. Source code is the human readable text of a computer program, written by programmers and compiled into binary format for execution by the computer. Without the source code, it is nearly impossible to modify a computer program, or even understand how it works. Proprietary software vendors like Microsoft keep their source code confidential, distributing binary-only software to rob users of the ability to modify it for their own purposes.
Water bathed the surface of southern Mars for millions of years, helping to create an environment theoretically capable of nurturing life, according to a new study into the planet's mysterious oceans.
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| ©Unknown |
An ancient horse-racing course that was written about in classical texts but thought lost has been discovered by archaeologists in Olympia in Greece, the Science Daily has reported.
The hippodrome, where the emperor Nero competed for Olympian laurels some 1,600 years ago, was discovered by a research team from Germany.
"This discovery is an archaeological sensation," said Norbert Muller of the Johannes Gutenberg University Mainz.
What if "eating local" in Shanghai or New York meant getting your fresh produce from five blocks away? And what if skyscrapers grew off the grid, as verdant, self-sustaining towers where city slickers cultivated their own food?
Dickson Despommier, a professor of public health at Columbia University, hopes to make these zucchini-in-the-sky visions a reality. Dr. Despommier's pet project is the "vertical farm," a concept he created in 1999 with graduate students in his class on medical ecology, the study of how the environment and human health interact.
Dickson Despommier, a professor of public health at Columbia University, hopes to make these zucchini-in-the-sky visions a reality. Dr. Despommier's pet project is the "vertical farm," a concept he created in 1999 with graduate students in his class on medical ecology, the study of how the environment and human health interact.
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| ©SOA Architects |
| "The Living Tower" |
