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6 | NewScientist | 27 April 2013 COULD China’s mega-engineering projects be making earthquakes more likely? The magnitude 6.6 quake that shook Sichuan province on 20 April, killing at least 180 people, was small compared with the magnitude 7.9 quake that struck the region in May 2008, claiming some 69,000 lives. But it was a sobering reminder that many of China’s engineering projects are vulnerable because they sit on fault lines – and raises questions about their seismic effect. In unstable regions like Sichuan, it is critical to look at the local effect of reservoirs, for example, says Shemin Ge of the University of Colorado in Boulder. Ge and her colleagues have suggested that the 2008 quake may have been partially triggered by the creation a few years earlier of the giant Zipingpu Reservoir 20 kilometres China rocked again from the epicentre. The reservoir ratcheted up the pressure on the rocks beneath. It’s too early to know whether reservoir-building contributed to last week’s quake. Of more urgent concern is the damage to dams and reservoirs, says Mian Liu of the University of Missouri, Columbia. According to the Ministry of Water Resources, two medium-sized and 52 small dams were damaged, with residents evacuated downstream of five of them. Determining the factors behind the recent quake could help inform where future projects are sited, says Ge. China has already planned to build 60 hydropower dams between 2011 and 2015, many of which will lie along fault lines which are also river courses. In theory, dams can be designed to withstand any amount of shaking. The 2008 quake redistributed pressure along the Longmen Shan fault line, says Liu. In the aftermath, he calculated that it had increased the risk of another magnitude-7 quake within the next 50 years by a few per cent. “Seems nature was in a hurry,” he says of last week’s quake. Carbon bubble THIS could get awkward. We need to stop burning fossil fuels to avoid the risk of dangerous climate change. But limiting the amount we can burn will take a chunk out of the global economy. A non-binding agreement is in place to try to limit global warming to 2 °C. If we are to honour it, we can only burn about a quarter of the planet’s existing fossil fuel reserves. A new report from the Carbon Tracker Initiative says this would slash the value of the biggest energy companies by between 40 and 60 per cent, because they have invested billions of dollars in exploring untapped resources. In effect, investors have created a “carbon bubble” by ploughing money into fossil fuel reserves that should not be exploited. The economic damage could be minimised if any climate agreement was phased in gradually, says Aled Jones of Anglia Ruskin University in Cambridge, UK. “The problem is we’re running out of time.” –Firm evidence remains scant– Texas blast poses puzzles SO MANY questions… The huge blast last week at the fertiliser plant in West, Texas, killed 14 and injured at least 200. Yet it is still not clear what chemicals were on site, precisely how the explosion happened and whether adequate safety precautions were in place. The West facility stored fertiliser – mainly anhydrous ammonia. Whether it also stored ammonium nitrate, a fertiliser doubling up as a component for explosives used to quarry rock, is something that officials from the US Chemical Safety Board will want to establish. Keith Plumb, an industry consultant on explosion prevention based at Integral Pharma Services in Cheshire, UK, says anhydrous ammonia alone could have been involved. The fire that broke out could have heated a tank of it, causing the tank to vent ammonia that then ignited. Some of the worst chemical plant accidents have involved similar facilities – prompting Joe Eades of the Ispahan Group, an engineering support firm in Singapore, to wonder why the town of West wasn’t evacuated at the first sign of fire. It has also emerged that the US Environmental Protection Agency fined the West plant $2300 in 2006 for not having an adequate risk management plan. The American Institute of Chemical Engineers rejects the notion that slack attention to safety led to the blast. “Standards only continue to become more rigorous,” says Scott Berger, executive director of the institute’s Center for Chemical Process Safety. WATCH out, SpaceX, there’s a new commercial rocket in town. Since the space shuttles retired in 2011, NASA has been contracting with private firms to deliver cargo – and eventually astronauts – to the International Space Station. California- based SpaceX became the first firm to resupply the ISS in October. Orbital Sciences of Dulles, Virginia, is now entering the fray. On 21 April, its Antares launch vehicle lifted off from the Mid-Atlantic Regional Launch marks loss of Xclusivity REUTERS/ADREES LATIF Spaceport on Wallops Island, Virginia. The maiden flight was purely to test the rocket, which carried a mock cargo capsule with the same mass and dimensions as the Cygnus capsule it is designed to ferry. After about 10 minutes, the capsule separated from the rocket and went into a temporary orbit. It will burn up on re-entry in about two weeks. A full test mission, in which a loaded Cygnus craft docks with the ISS, will follow. UPFRONT “China plans 60 new dams by 2015, many of which are on fault lines which are also river courses”
