Where it is and what it carries
The Easter Plate, also called the Easter Microplate, covers about 167,000 square kilometers, or 0.03% of Earth’s surface. It lies in the southeast Pacific Ocean, between about 22° and 27° south, west of Easter Island. It sits on the East Pacific Rise, the fast-spreading boundary between the Pacific Plate and the Nazca Plate.
The plate is made of young oceanic crust under deep water. It carries no islands. Easter Island, which belongs to Chile, lies to the east on the Nazca Plate.
What happens at its edges
The Easter Plate has just two neighbors, but both boundaries are long and active.
On its western side, the plate meets the Pacific Plate along a 923 km boundary made of spreading ridge segments and transform faults. The average relative speed is about 8.3 cm/yr, with a wide range along the boundary because the microplate is rotating.
On its eastern side, it meets the Nazca Plate along an 860 km boundary at about 6 cm/yr on average. Most of this boundary is spreading ridge, but a 160 km stretch is compressional, where the rotating block pushes against the Nazca Plate instead of pulling away.
That mix of spreading and squeezing along one boundary is typical of rotating microplates. As the block turns, some parts of its edges open and others close.
Why geologists separate it
Marine surveys mapped two separate ridges here, the East Rift and the West Rift, with a block of seafloor between them. Magnetic stripes on the seafloor and earthquake patterns show that this block rotates quickly and independently of both the Pacific and Nazca plates. It is one of the best studied examples of how microplates form when a spreading ridge reorganizes.
The Easter Plate is one of two such microplates on the southern East Pacific Rise. The other, the Juan Fernandez Plate, lies farther south.
Earthquakes
The dataset lists three earthquakes of magnitude 6.5 or larger on the Easter Plate since 1900, all in the open ocean far from any town. The largest was an M6.8 event in 2022. The others were an M6.6 in 2004 and an M6.5 in 1935. The plate has no named volcanoes in the dataset, though new crust forms constantly along its spreading ridges.