Linhoff measures several isotopes in glacial meltwater. Radon and radium come from bedrock at the base of the glacier and reveal the pathways glacial meltwater takes. Beryllium is formed by cosmogenic rays from the sun and helps track the component of meltwater derived from melting snow on top of the ice sheet. Isotopes of oxygen and hydrogen are used to quantify the component of the meltwater derived from melted ice.
(Photo by Chris Linder, Woods Hole Oceanographic Instistution)