The International Ocean Discovery Program (IODP) is now accepting applications for scientific participants on Expedition 391 Walvis Ridge Hotspot aboard the JOIDES Resolution. Expedition 391 is a scientific ocean drilling project that seeks to understand the geodynamic significance and origin of the Walvis Ridge (WR), a long-lived hotspot trail that began ~132 Ma at the opening of the South Atlantic Ocean. Because of its duration and volcanic expression, WR is the most influential of Atlantic hotspots and is thought to have a deep mantle plume source that can be projected to the edge of the African large low shear wave velocity province (LLSVP), a hypothesized plume generation zone. The hotspot displays long-lived (since ~70 Ma) isotopic zonation, a characteristic thought to originate at the LLSVP edge, and may be the first example of a hotspot split into three isotopically distinct seamount chains. The hotspot interacted with the Mid-Atlantic Ridge (MAR) for most of its early history, producing both the WR and Rio Grande Rise (RGR). Valdivia Bank, a WR plateau, may have formed with the RGR around a microplate, and this added complexity raises questions about simple plume models and the geodynamic implications of this hotspot trail. Opportunities exist for researchers (including graduate students) in all shipboard specialties, including but not limited to sedimentologists, petrologists, micropaleontologists, paleomagnetists, petrophysicists, borehole geophysicists, inorganic and organic geochemists, and microbiologists. The deadline to apply to sail is October 1, 2019.