Laboratory Manual for Introductory Geology 4e

EXERCISE 2.12
Long-Term Movement of the Pacific Plate
Name:
Course:
Section:
Date:
The oldest volcano of the Hawaiian–Emperor seamount chain was once directly above the hot spot, but is now in the
northern Pacific, thousands of kilometers away (see the figure below). Seamount ages show that the hot spot has been
active for a long time and reveal the direction and rate at which the Pacific Plate has moved.
(a) What evidence is there that the Pacific Plate has not always moved in the same direction?
(b) How many years ago did the Pacific Plate change direction? Explain your reasoning.
Bathymetry of the Pacific Ocean floor, showing ages of volcanoes in the Hawaiian–Emperor seamount chain.
Meiji seamount
(71.4 Ma)
Nintoku seamount
(56.5 Ma)
Kimei seamount
(40 Ma)
Midway Island
(28.3 Ma)
Hawaii
(less than 1 Ma)
0 600
km
1,200
(continued )
2.5 PROCESSES AT PLATE BOUNDARIES REVEALED BY EARTH FEATURES
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