The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million km2 (40 million sq mi), it is the largest tectonic plate.

The Gorda Ridge, aka Gorda Ridges tectonic spreading center, is located roughly 200 kilometres (120 mi) off the northern coast of California and southern Oregon. Running NE – SW it is roughly 300 kilometres (190 mi) in length. The ridge is broken into three segments; the northern ridge, central ridge, and the southern ridge, which contains the Escanaba Trough.