Earth/Environment

How Antarctica got its ice East Antarctica’s great ice sheet was already present — and bigger than today — by 14.7 million years ago, about a million years earlier than some scientists had thought. A 1,100-meter-long core drilled off the Antarctic coast in McMurdo Sound shows when ice affected the sediments settling on the seafloor. Knowing Antarctica’s glacial history helps scientists better understand past climate and how the modern ice sheet might respond to warming temperatures. Sandra Passchier of Montclair State University in New Jersey and her colleagues report the discovery in an upcoming Geological Society of America Bulletin . — Alexandra Witze Extreme Chinese dust-ups Storms in parched regions of Asia fling major dust clouds into American airspace each spring, but five events in April 2010 contributed to the thickest and most divided pollutant streams ever recorded, a U.S.-Japanese team reports. The researchers used NASA satellites to track multiple layers of airborne dust stemming from China’s Taklimakan and Gobi deserts. Dust clouds entered North American air at between 2 and 10 kilometers altitude, maintaining an average width of more than 2000 kilometers, the scientists reported online April 19 in Atmospheric Chemistry and Physics Discussions. Excessively strong, sustained winds ferried the dust north into Canada and east to at least Virginia. — Janet Raloff Heating up malaria risks in birds For every 1 degree Celsius increase in local temperature, the rate of malaria infection in wild birds has doubled or tripled, a new study finds. This link proved especially robust for populations in Europe and Africa. László Garamszegi of the Do±ana Biological Station in Seville, Spain, surveyed records spanning 70 years and involving 3,335 avian species. His analysis, detailed in the May Climate Change Biology , shows that changes in infection rates are strongly linked to local temperature, and “the increase in prevalence has accelerated in recent years.” These data suggest that there could be similar climate-related increases in human malaria risks, he says. — Janet Raloff