Bruce Nelson is a geochemist who studies the origin and evolution of the continental crust, seafloor hydrothermal processes and the geochemical evolution of the Earth’s mantle. He works all over the globe, and his recent studies include an investigation into the sources of granites and basalts in the Cascade Range of the Pacific Northwest, volcanism in the Kamchatka arc in Russia, and volcanism in the Hawaiian and Canary Islands. His research also addresses more immediate environmental concerns: one of his projects looked at the chemical signatures of toxic metals accumulating in Puget Sound, the Columbia River, and northern Washington lakes.