Hotspots
Geo 12
Name______________
In the following you will be investigating the Hawaiian Island chain, a chain of islands in the Pacific
Ocean created by hotspot volcanism.
1. Using past notes or other resources, name the plate upon which the Hawaiian Islands are located.
Where on the plate are the Hawaiian Islands located (edge; central; etc.)?
2. Look carefully at the following figure 19.46. Notice that the mantle plume is stationary. As the
lithospheric plate moves over the mantle plume, a chain of dormant volcanoes is created.
Current
position of
plume
Using this information, and the next figure 19.47, under which Hawaiian island is the hotspot located?
How do you know?
3. As the lithospheric plate moves over the mantle plume, the volcano that was created over the
hotspot is also moved (much like baggage on a conveyor belt). This creates a chain of dormant
volcanoes. The plate upon which the Hawaiian Islands are located is moving in a north westerly
direction. Looking at figure 19.47 above, notice that the islands become older as one moves
northwestwardly of Hawaii. The island of Hawaii is the youngest volcano. Using the hotspot theory,
explain this age distribution. In other words, why do the islands get progressively older to the
northwest?
4. Locate and mark the Hawaiian Islands on the figure below.
The map depicts the ocean floor as it would be seen if ocean water did not exist. Notice that the
Hawaiian Island chain continues underwater in a north-westerly direction, and then continues in a more
northerly direction to the Aleutian Islands. This chain of underwater volcanoes is named the Emperor
Seamount Chain. Each of the volcanoes in the chain was created by the mantle plume located under the
island of Hawaii. The oldest underwater volcano (or seamount) is approximately 70 million years old
and is located just south of the Aleutian Islands. From the knowledge you have acquired about plate
tectonics, with continued north-westerly movement of the Pacific Plate, what will be the eventual fate
of the oldest seamount?
5. Notice the kink in the Emperor Seamount Chain. This shift in direction of the Pacific occurred
approximately 46 million years ago. Coincidentally, at approximately the same time, India collided with
Asia. Suggest a link between the two events based on your knowledge of plate tectonics.
Multiple Choice
6. The formation of the Hawaiian Islands is associated with: a) convergent plate boundaries b0
divergent plate boundaries c) transform plate boundaries d) both divergent and convergent plate
boundaries e) no plate boundary of any kind
7. The island of Hawaii is volcanically active because it is located: a) above a deep ocean trench b)above
a hotspot c) near a transform fault d) in the asthenosphere e) above a mid-ocean ridge.
8. Both the Hawaiian Islands and the Emperor Seamount Chain were formed by: a) a hotspot that
migrates in a north-westerly direction under the Pacific Plate b) a hotspot that migrates in a southeasterly direction under the Pacific Plate c) a mantle plume that is continually moving under the Pacific
Plate d) the Pacific Plate that is moving in a north-westerly direction over a stationary hotspot e)the
Pacific Plate that is moving in a south-easterly direction over a stationary hotspot