1. Hot Spot Volcanoes
Animation
Animation 2

2. Volcanic activity at mid-ocean ridge can form ocean islands (e. g
Volcanic activity at mid-ocean ridge can form ocean islands (e.g., Iceland).

3. Volcanic Activity at Tectonic Plate Boundaries
Source: USGS

4. However Not all volcanoes occur at plate boundaries.
HOT SPOTS: areas of volcanoes that result from plumes of hot solid material that have risen from deep within Earth’s mantle.

5. Map of hot spots

6. Hawaiian Islands
Source: USGS

7. Northwest Movement of Pacific Plate Over Fixed Hawaiian Hot Spot
Source: USGS

8. Ages of Hawaiian Islands
Source:

9. Hot Spot Volcanism
All of the mountains in this map of the floor of the Pacific Ocean are volcanoes
Note that there are several long chains of volcanoes
But there are also many individual volcanoes
None of these volcanoes are formed along plate boundaries

10. Hot Spot Volcanism
These isolated areas of volcanic activity are not associated with plate boundaries
These volcanoes are found both on continents and out in the ocean

11. Hot Spot Volcanism
A plume of hot mantle material rises up to the bottom of the lithosphere
Melting occurs and magma is created
These are called “hot spots”
They can last for many millions of years

12. Hot Spot Volcanism
The magma works its way to the surface over the hot spot and a volcano is formed
Out in the ocean, the volcano may or may not reach the surface and form an island
In fact, few oceanic volcanoes reach the surface

13. Hot Spot Volcanism
As the moving plate carries the volcano away from the hot spot, the volcano dies out
With time, another volcano may form
This cycle may repeat many times, forming a long chain of under sea volcanoes and islands

14. Hot Spot Volcanism
The Hawaiian Islands are the classic example of hot spot volcanism

15. Hot Spot Volcanism
Every island in the Hawaiian Island chain was created by volcanic eruptions that occurred as the Pacific Oceanic Plate crossed over a hot spot

16. Hot Spot Volcanism
In fact, the 7 main Hawaiian Islands are just the southern most portion of two great undersea mountain ranges, composed of hundreds of volcanoes, that runs for 6000 kilometers (4000 miles) across the floor of the Pacific Ocean

17. Hot Spot Volcanism
The plate has moved to the northwest for more than 65 million years
The big island of Hawaii is now over the hot spot

18. Hot Spot Volcanism
The volcanoes that formed the Hawaiian islands are classified as shield volcanoes

19. Hot Spot Volcanism
Shield volcanoes are characterized by broad, gentle slopes built up from repeated basaltic lava flows

20. Hot Spot Volcanism Not all eruption create big islands
Molokini represents one eruption that is slowly being reclaimed by the sea

21. Hot Spot Volcanism
Loihi Volcano, the youngest volcano of the Hawaiian Island Chain, lies about 20 km off the south coast of the Big Island
Currently it rises 3500 meters above the surrounding sea floor and its summit is about 1000 meters beneath the surface

22. Fast and Slow Changes to Earth’s Surface
Changes due to Plate Tectonics
Fast: Earthquakes and volcanoes
Slow: Continental Drift

23. Fast Process: Volcanoes and Hot Spots
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