Groundwater is an important pathway for materials to flow from land to sea. This is particularly true for materials that are concentrated in groundwater due to chemical interactions between water and aquifer rocks as groundwater flows to the coast.
This study, published in Nature Communications, evaluated groundwater samples from around the world, many collected during previous field sampling efforts, and found that groundwater contributes important amounts of those elements to the ocean. Chemical cycles, including transport between the land and the ocean, are important to understand for many reasons. Some of these elements are used to reconstruct climate in the past, when there are no direct observations, so accurate knowledge of groundwater fluxes is important. This work was supported by the National Science Foundation and U.S. Geological Survey.