Download Volcanoes and Plate Tectonics

Volcanoes and Plate Tectonics
Question
Where are volcanoes
found?
Answer
Volcanoes form along the
boundaries of Earth's
plates.
What is a hot spot?
An area where material
from deep within the
mantle rises, and then
melts, forming magma.
Ring of Fire
What is a volcano?

a weak spot in the crust where molten
material, or magma, comes to the surface
What is Magma?
A molten mixture of rock-forming substances,
gases, and water from the mantle.
When does magma become lava?

When magma reaches the surface.
What is the Ring of Fire?

a major volcanic belt formed by the many
volcanoes that rim the Pacific Ocean.
Where do volcanoes come from?

along diverging plate boundaries such as
mid-ocean ridges and along converging plate
boundaries where subduction takes place.
Describe how volcanoes form along
the mid-ocean ridge?

Along the rift valley,
lava pours out of
cracks
in the ocean floor,
gradually building
new mountains.
True or false?

Volcanoes can form along diverging plate
boundaries.
True or false?

Many volcanoes form near converging plate
boundaries where oceanic crust returns to the
mantle.
How does subduction at
converging plate boundaries lead to
the formation of volcanoes

When the older, denser plate sinks beneath a
deep-ocean trench into the mantle, some of the
rock above the subducting plate melts and
forms magma. Because the magma is less dense
than the surrounding rock, it rises toward the
surface. Eventually, the magma breaks through
the ocean floor, creating volcanoes.Volcanoes
can also form where oceanic crust is subducted
beneath continental crust.
Island arc?

Volcano boundaries where two oceanic plates
collide to create a string of islands
Name of 6 major island arcs?
Japan,
 New Zealand,
 Indonesia,
 the Philippines,
 the Aleutians,
 the Caribbean islands

What is a hot spot?

an area where material from within the
mantle rises and the melts, forming magma
How did the Hawaiian Islands form??

They formed over millions of years as the
Pacific plate drifted over a hot spot.
How do volcanoes change Earth’s
surface?

When lava that has erupted from a volcano
cools, it forms solid rock. In this way,
volcanoes add new rock to existing land and
form new islands.
Why do so many of Earth’s volcanoes
occur at plate boundaries?

At the boundaries where plates diverge (pull
apart) or converge (push together), the crust
is weak and fractured, allowing magma to
reach Earth's surface
Explain how hot spots created the
Hawaiian Islands.

Lava erupted from the hot spot and built a
volcanic island. The Pacific plate is slowly
moving over the hot spot, so it carried the
island away from the spot. Another volcanic
island formed at the hot spot and then was
carried away. Over time, a chain of islands
formed.
What is the difference between
magma and lava?

Magma is molten, rock-forming material
underground. Magma that reaches the surface
is called lava.
Define volcano

a weak spot in Earth's crust where magma
comes to the surface
Define Ring of Fire

a belt of many volcanoes that rim the Pacific
Ocean
Define island arc

a chain of volcanic islands that forms at the
boundary where two oceanic plates push
together and one plate subducts under the
other plate