Noteform 3-1: Volcanoes and Plate Tectonics (pages 82 – 85)
Name: ____________________________________________ Section: __________
1. The ancient Greeks believed that Mount Etna, now in Italy, was the home of
Hephaestus, the god of:
________________________.
2. A _________________________ is a weak spot in the crust where molten
material, or magma, comes to the surface.
3. _________________________ is a molten mixture of rock-forming substances,
gases, and water from the mantle.
4. When magma reaches the surface, it is called: _________________________.
5. There are about ___________ active volcanoes on land and many more beneath
the sea.
6. One major volcanic belt the encircles the rim of the Pacific Ocean is called:
_________________________________.
7. At plate boundaries, huge pieces of the crust diverge ( ) or converge ( )
and as a result, the crust often fractures, allowing magma to reach the:
______________________________.
8. Volcanoes form along ________________________, which mark diverging
oceanic plate boundaries. Along the rift valley, lava pours out of cracks in the
ocean floor, gradually building new:
___________________________.
9. Volcanoes can also form along diverging plate boundaries on land such as along
the:
______________________________ in East Africa.
When two oceanic plates collide, the _______________, ________________ plate
sinks beneath a deep-ocean trench into the mantle, where some of the rock above the
subducting plate:
______________________ and forms magma.
10. Because the magma is less ______________________ than the surrounding rock,
it rises toward the:
___________________________.
11. The resulting volcanoes formed by two colliding and subducting oceanic plates
creates a string of islands called an:
_____________________________.
12. Besides Japan, list three other island arcs: __________________________,
_____________________________ & __________________________.
13. Volcanoes also occur where and oceanic plate is __________________________
beneath a continental plate. Collisions of this type produced the volcanoes of the
Andes Mountains in South America and the US volcanoes of the Pacific
__________________________.
14. Some volcanoes result from “hot spots” in Earth’s _______________________.
15. A volcano forms above a hot spot when magma erupts through the crust and
reaches the surface. Do hot spots occur in the middle of plates, far from plate
boundaries, or do they occur on or near plate boundaries?
A)
B)
C)
D)
hot spots occur in the middle of plates
hot spots occur at plate boundaries
hot spots occur in the middle of plates and at plate boundaries
hot spots only occur at the North and South poles
16) Besides the Hawaiian Islands, where else in the USA can you find a hot spot?
At _______________________________________ in Wyoming