One of the seven major plates moving about on the earth's surface.
The Pacific Plate is an
oceanic plate and covers about 20% of the
earth's surface. It is moving northwest at a
rate of about 2 cm/year.
Boardering the southeastern side of the Pacific plate is the East Pacific Rise
located in the center of the
Pacific Ocean. It is a
spreading center
which causes the plate to move toward the northwest.
The northeastern margin (near
California) of the Pacific Plate is
experiencing
shearing forces as the
North American plate rubs against
it. This creates a good deal of
earthquake activity in western
North America.
Towards the north and western ends, the Pacific Plate is being subducted by
the North American Plate, the Eurasian Plate, the
Phillippine Sea plate and
the Indian-Australian plate. Subduction along the western boundaries
creates the deep-sea
trenches and
volcanic islands that occur in these areas.
For more information on this subject, see
plate tectonics.