Sedimentology

Deep beneath Alaska’s Aleutian Islands, down where the pressure and temperatures have become so high that rock starts to flow, new continental crust is being born. Scientists have long believed that continental crust forms in volcanic arcs – they know the magma brought up in the arcs’ volcanoes is geochemically very similar to continental crust. The lingering question has been how exactly that happens. While the magma that reaches the surface is similar to continental crust, the lower crust beneath volcanic arcs is quite different from the lower half of continental crust.

A new study finds that the Horn of Africa has become progressively drier over the past century and that it is drying at a rate that is both unusual in the context of the past 2,000 years and in step with human-influenced warming. The study also projects that the drying will continue as the region gets warmer. If the researchers are right, the trend could exacerbate tensions in one of the most unstable regions in the world.

A geochemist who studies the workings of the deep earth and their influence on some of the world’s most explosive volcanoes has been awarded a $500,000 MacArthur Fellowship. Terry Plank, a researcher at Columbia University’s Lamont-Doherty Earth Observatory, joins novelist Junot Diaz, war correspondent David Finkel and filmmaker Natalia Almada in this year’s batch of MacArthur Fellows, who will receive $100,000 a year for five years, no strings attached. Maria Chudnovsky, a mathematician at Columbia’s Engineering School who studies the fundamentals of graph theory, also received a genius grant.

The Hudson River that explorer Henry Hudson sailed some 400 years ago had no power plants on its shores. No trains, bridges, factories or houses. Those innovations changed the river, leaving a legacy of PCBs, sewage and other pollutants. But pollution is just one way that humans have transformed the river. A small way, it turns out.