Ars Technica: In 2001, seismometers in the Spokane, Washington, area recorded more than 100 earthquakes, some as large as magnitude 4.0. One of the characteristics of the 2001 activity was the reports of loud booms, which are often associated with small quakes. Examining data recorded by the European Space Agency’s GOCE satellite during the 2011 Tohoku earthquake, an international team of researchers has determined that large earthquakes also produce sound waves, but at infrasonic wavelengths. The satellite’s accelerometer detected the passing sound wave at an altitude of 270 km. It was also able to detect changes in atmospheric density due to the sound wave’s compression of the air. The compression increased the drag on the satellite, causing it to activate control jets to maintain a precise orbit. Researchers from the US Geological Survey and the Pacific Northwest Seismic Network have begun using satellite data to understand the nature of seismic events in the area. Interferometric synthetic aperture radar measurements from European Space Agency and Canadian Space Agency satellites showed surface movement of 15 mm along a thrust fault that passes through the city’s center. Computer models suggest that the quake activity was centered at depths of 0.3 to 2 km.
Science News: In some caves in Russia, speleothems, or mineral deposit formations such as stalactites and stalagmites, have been growing for as many as 500 000 years. They form when air temperatures in areas containing permafrost are warm enough to cause it to melt, which sends mineral-laden water seeping into the caves. By using radiometric dating to determine when the different layers of speleothems formed, Anton Vaks of the University of Oxford and his colleagues studied Earth’s fluctuating climate. Their results were published online in Science. What they found is that global temperatures only slightly higher than those of the present day can thaw significant regions of permafrost. Because permafrost can contain twice as much carbon as the atmosphere, its melting can have a huge effect on climate and global warming.
Nature: Ernest Moniz, director of the MIT Energy Initiative, appears to be President Obama’s choice to follow Steven Chu as secretary of the Department of Energy. Unlike Chu, who was considered a government outsider, Moniz has previously served in several government positions. From 1995 to 1997 he was an assistant director of the White House Office of Science and Technology Policy and then served until 2001 as an undersecretary of energy. For the last four years while working at MIT, he has also been a member of the President’s Council of Advisors on Science and Technology. A nuclear physicist with experience working on clean and alternate energy programs, Moniz is expected to continue Chu’s efforts to refocus DOE’s research in those areas. However, he has faced some criticism for a 2011 report on natural gas that suggested that hydraulic fracturing could help expand the US natural gas industry. A sense of Moniz’s policy positions can be found in the article “Meeting energy challenges: Technology and policy,” which he wrote with Melanie Kenderdine for the April 2002 issue of Physics Today.
BBC: Astronomers have been studying video footage to calculate the origin of the meteor that struck Russia on 15 February. From images captured by car-dashboard cameras, camera phones, and CCTV, Jorge Zuluaga and Ignacio Ferrin of the University of Antioquia in Medellin, Colombia, were able to determine the trajectory of the meteor in Earth’s atmosphere and then use that calculation to reconstruct its orbit in space prior to entering the atmosphere. According to their findings, which have been published on the arXiv e-print server, the meteor belongs to the Apollo class of asteroids, a group of near-Earth asteroids whose elliptical orbit crosses that of Earth and can come near enough to the planet to pose a threat. The Chelyabinsk meteor appears to have originated in our solar system, most likely in the asteroid belt between Mars and Jupiter.