Laboratory Manual for Introductory Geology 4e

detected by underwater oceanographic surveys. The Hawaiian–Emperor seamount
chain tracks the motion of the Pacific Plate and lets us interpret its motion over a
longer time span than that recorded by the Hawaiian Islands alone.
In Exercises 2.11 and 2.12, you will examine both the Hawaiian Islands (as hotspot
volcanic islands) and the Hawaiian–Emperor seamount chain to determine the
history of Pacific Plate movement.
EXERCISE 2.11
Determining Ancient Plate Direction: Footprints of a Moving Plate
Name:
Course:
Section:
Date:
The Hawaiian Islands, located in the Pacific Ocean far from the nearest mid-ocean ridge, are an excellent example of
hot-spot volcanic islands (see the figure below). Volcanoes on Kauai, Oahu, and Maui haven’t erupted for millions of years,
but the island of Hawaii hosts five huge volcanoes, one of which (Kilauea) has been active continuously for more than
30 years. In addition, a new volcano, already named Loihi, is growing on the Pacific Ocean floor just southeast of Kilauea.
As the Pacific plate continues to move, Kilauea will become extinct and Loihi will become the primary active volcano.
(a) Where is the Hawaiian hot-spot plume located today relative to the Hawaiian Islands? Explain your reasoning.
(b) Draw a line connecting the volcanic center (highlighted in red) on Maui to Kilauea (the currently active volcano on
Hawaii). Connect the volcanic centers of Maui to Molokai, Molokai to Oahu, and Oahu to Kauai as well.
Ages of Hawaiian volcanoes in millions of years (Ma).
Niihau
5.1 Ma
Kauai
2.35 Ma
Seamount
Oahu
1.83 Ma
Molokai
Lanai
1.32 Ma
Maui
Motion of Pacific Plate
Pacific Ocean
Kahoolawe
Hawaii
Kilauea
0 50 mi
0 50 km
Loihi
volcano
(continued )
2.5 PROCESSES AT PLATE BOUNDARIES REVEALED BY EARTH FEATURES
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