Ice at minus 10 degrees Celsius releases more iron from common minerals than liquid water at 4 degrees Celsius, according to a team of researchers from Umeå University, the Institut des Sciences Chimiques de Rennes and CNRS. “It may sound counterintuitive, but ice is not a passive frozen block,” said Umeå University’s Professor Jean-François Boily. As the ice freezes and thaws, organic compounds that were previously trapped in the ice are released, fuelling further chemical reactions. “Each cycle releases iron from soils and permafrost into the water. Ice as a kinetic and mechanistic driver of oxalate-promoted iron oxyhydroxide dissolution.