Did you know the first time Marie Tharp presented her analysis of the Atlantic sonar data, that revealed oceanic rift valleys to her collaborator, he dismissed it at "girl talk"? Read Marie Tharp's incredible story and how she literally shaped our understanding of the world in the Geological Society of America's most recent "GSA Rock Stars" article in GSA Today. Tharp's work led to the publication of bathymetric maps displaying planet-length oceanic rift valleys that we know today as pivotal evidence in support of plate tectonics.