Whatever is down there was strong enough to shake the entire Pacific plate.
You're not going to stop the whole Pacific plate from moving toward Alaska.
Most important, though, is the fact that the Pacific Plate is moving.
The plate is moving easterly along with the Pacific plate.
Nauru is moving at 104 mm per year to the north west along with the Pacific Plate.
The Pacific plate is being subducted under the islands, forming the trench.
They may have rumpled up in response to the impact of the Pacific plate on the continental California coast.
A transform boundary forms the northern border with the Pacific Plate.
That is the boundary between the North American and Pacific plates.
Bird considers it to be unconnected to the Pacific Plate.