The Vance Seamounts are a group of seven submarine volcanoes located west of the Juan de Fuca Ridge. Most of the seamounts contain a caldera. They are the southernmost of several near-ridge chains located on the Pacific Plate, stemming from the Juan de Fuca Ridge. The construction of the cones left a lot of debris scattered across the ocean surface, much of which is aligned parallel to the ridge axis. The largest of these cones are nearly 2 km (1 mi) across, whereas the smallest appear to be only a few hundred meters in diameter.