1 Volcanoes around the World

Question 1

volcanoes form at the _________

Answer 1

subduction zone.

Question 2

At ______________,
tectonic plates move ______(closer/ away) from one another to produce _________. Hot magma rises from
the mantle pushing the plates (apart/ to each other).

Answer 2

divergent boundaries
away
volcanoes
apart

Question 3

Volcanoes can also form above
a column of superheated
magma called a ___________.

This may happen in areas that
are distant from ____________. It is also referred
to as ______ or_________

Answer 3

mantle plume
plate boundaries
hotspot or intraplate volcanism

Question 4

What is Volcano?

Answer 4

any opening in the ground
where magma or molten
rock comes out.

Question 5

volcanoes are found in the _______________

Answer 5

pacific ring of fire

Question 6

A Canadian geophysicist and
one of the pioneers of the
theory of plate tectonics.

He states that volcanic chains
like Hawaiian islands result
from the slow movement of a
tectonic plate across a fixed
hotspot.

Answer 6

John Tuzo Wilson

Question 7

He further developed Wilson’s
theory and he also explained
hotspots.

Answer 7

William Jason Morgans

Question 8

_________ are locations on
Earth’s surface that have
experienced active volcanic
activities for a long period of
time.

Answer 8

Hotspots

Question 9

When is a volcano
considered active?

Answer 9

● The volcano has erupted within
historical times.
● Account of the eruptions were
documented
● The volcano has erupted at least once
within the last 10,000 years

Question 10

PHIVOLCS

Answer 10

Philippine Institute of Volcanology and Seismology

Question 11

Most active volcanoes are distributed around
world.
Such volcanoes are:

Answer 11

1. Mt. St. Helens in United States
2. Mt. Pelee in Martinique
3. Mt. Etna and Mt. Vesuvius in Italy
4. Mt. Mayon and Mt. Pinatubo in Philippines
5. Mt. Krakatoa in Indonesia

Question 12

About 95% of the world’s volcanoes
are located near ______________ while the remaining 5% are thought to be associated with
____________ and _________.

Answer 12

boundaries of tectonic plates
mantle plumes
hotspots

Question 13

PLATE TECTONIC
THEORY

Answer 13

It states that lithospheric
plates on the scales of
continents and ocean floors
are constantly moving in
response to the movements in
the mantle.

Question 14

theories about movement of crust
(2)

Answer 14

Mantle Convection Theory
Slab Pull Theory

Question 15

What energy source accounts for plate motion?

Answer 15

Earth’s internal heat

Question 16

He proposed the Mantle Convection Theory

Answer 16

Arthur Holmes

Question 17

Holmes suggested that as the
mantle became heated, its
density _________ and
eventually _________. When the
material cooled, it would sink
exhibiting a _______ behavior
like a conveyor belt. The
pressure of heated magma
broke the continents apart,
forcing the pieces to drift in
_______ directions.

Answer 17

decreases
rises up
circling
opposite

Question 18

It states that gravity and the plates
themselves are the ones responsible for
the plate tectonics through subduction
process. Subduction zones exist at the
outer edges of plates. In these zones,
rocks are older hence they are cooler
and denser compared to those located
at the inner layers. The old rocks or
slabs also subduct or sink into the
mantle below it, due to gravitational
forces.

Answer 18

Slab Pull Theory

Question 19

The hotter mantle rocks are
less dense and cooler rocks are
denser. As a result, the hotter
rocks rise while cooler rocks
sink. The rising and sinking of
mantle rocks lead to formation
of convection currents.

Answer 19

Mantle Convection