High-resolution surveys along the hot spot–affected Galápagos Spreading Center: 2. Influence of magma supply on volcanic morphology

The Galápagos Spreading Center (GSC) at 89°–95°W exhibits large gradients in magma supply at a relatively constant intermediate spreading rate, making this area an ideal natural laboratory to study the effects of magma supply on volcanism at seafloor spreading ridges. Prior work shows that the GSC develops from axial valley to shallow axial rise and a shallow magma sill, much like a typical fast spreading ridge, as the contribution of the hot spot increases. The volcanic morphology varies with magma supply in a predictable manner that we divide into three terrains based on the characteristic style of volcanic emplacement and edifice construction within each terrain. The volcanic cone terrain comprises most of the GSC and is characterized by prominent volcanic cones within a >1 km wide and >100 m deep axial graben. Approaching the area of maximum mantle plume influence at 91°W, the GSC axis lies along an elevated axial rise split by a