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4 | NewScientist | 2 July 2011 OVER 5000 homes damaged by the earthquakes that hit Christchurch will not be rebuilt at present, the New Zealand government announced last week. The magnitude 7.0 and 6.3 quakes that shook the city in September 2010 and February this year caused extensive structural damage. Crucially, the quakes weakened the soil beneath large areas of the city through a process called liquefaction, whereby pressure from shaking ground transforms wet but solid sand into unstable slurry. The government has published a map outlining areas where the damage is too severe to rebuild in the near-term. Mark Quigley, a seismologist at the University of Canterbury in Christchurch, who lives in an affected house, says that continuing seismic activity means many properties are vulnerable Quake homes lost to repeated liquefaction. Once liquefied sediment settles it can sink, increasing the risk of flooding, he says. The worst affected areas of the city have sunk by 1 metre. Quigley says the land could be rebuilt on, but it would be expensive and take many years. Land that holds critical infrastructure, like transport systems, is being reused by pushing concrete piles with metal reinforcements through the liquefied layer and into the bedrock to create solid foundations. Thomas Wilson of the University of Canterbury says the liquefied layer is 10 metres thick in some areas, making it “economically challenging” to reinforce the entire city. Both Quigley and Wilson believe the decision not to rebuild some of their city is sensible. “It’s an opportunity to increase the resiliency of Christchurch,” Wilson says. Geosciences New Zealand, a government project, predicts that there is a one-in-four chance that a quake greater than 6.0 will hit the area around Christchurch in the coming year. Radioactive urine FUKUSHIMA’S legacy is still unfolding. Radioactive elements have been found in the urine of 15 people in Iitate and Kawamata, 35 to 40 kilometres away from the stricken Japanese nuclear plant. These are the first results from a planned 30-year project to monitor the 2 million residents of Fukushima prefecture for signs of radiation exposure. Nanao Kamada of Hiroshima University and colleagues found iodine-131 at doses of up to 3.2 millisieverts in six people in the first round of tests in early May, but none in late May, and radioactive caesium in all 15 in both rounds. This brings the dose in the two months following the disaster to between 4.9 and 14.2 millisieverts. The “safe” annual dose is 20 millisieverts. Richard Wakeford of the Dalton Institute in Manchester, UK, says the levels should not pose too much of a hazard provided they fall in coming months. But he expressed surprise that iodine-131, with a half-life of eight days, was found in urine as late as May. –Consumer instincts– Billboards target monkeys SUBTLE it ain’t. The first advertising campaign ever to be aimed at non-human consumers, unveiled at the ad industry’s Cannes Lions Festival on 25 June, will use blatant sex to persuade its audience. The unsuspecting consumers are a colony of capuchin monkeys, who will later be invited to choose between two competing brands of food. Keith Olwell and Elizabeth Kiehner of New York ad agency Proton created the campaign with primatologist Laurie Santos of Yale University. Captive capuchins understand money and behave in similar ways to humans in economic games. So the team wondered if they would respond to advertising too. They are creating two food brands, one backed by two billboards that will hang outside the monkeys’ enclosure. “The foods will be novel to them and are equally delicious,” says Olwell. Designing the campaign threw up some special challenges. Capuchins “do not have language or culture and have very short attention spans”, says Olwell. “We had to get to the absolute core of what is advertising.” New Scientist has seen the two billboards. We cannot show them until the study is over, but can reveal that one shows a graphic shot of a female monkey’s genitals alongside brand A’s logo. The other shows the alpha male of the colony, also with brand A. The campaign should kick off in the coming weeks. Watch this space for updates on this venture into monkey consumerism. “The worst affected areas of Christchurch have sunk by 1 metre, increasing the risk of flooding” TALK about a tough road to climb. On 24 June, mission scientists endorsed two landing sites for NASA’s next Mars rover from a shortlist of four. One of the two would see Curiosity ascend a mound nearly as high as mount Kilimanjaro. Where to land the $2.5 billion robot, due to blast off in November, has been debated for years. NASA will mull over the recommendations but is not obliged to follow either of them. One pick is the 150-kilometre-wide Mars landing sites down to two PETE OXFORD/MINDEN/FLPA Gale crater (pictured), which hosts a 5-kilometre-high mound and is thought to have once been filled with water. Because the oldest rocks are at the mound’s base, as it ascends the rover would track how the planet’s chemistry – and potential habitability – changed over time. The other pick is another former crater lake, Eberswalde. It is further from the equator and therefore colder, so the rover would require more heating to function there. UPFRONT
