formation of volcanoes

Question 1

what are volcanoes

Answer 1

are vents in the Earth’s outermost layer called the crust that ejects volcanic materials such as molten rocks and gasses.

Question 2

how many volcanoes are there worldwide

Answer 2

1500

Question 3

philvocs meaning

Answer 3

the philippine institue of vocabology and seismology

Question 4

The government agency that studies and monitors volcanic activities and earthquakes in the Philippines.

Answer 4

(PHIVOLCS)

Question 5

how many active volcanoes listed in the ph

Answer 5

23 active volcs

Question 6

how many potentially active listed in the ph

Answer 6

26 potential active volcs

Question 7

how many inactive volcanoes in the ph

Answer 7

more than 300 named and unnamed inactive volcanoes in the PH

Question 8

country part of the pacific ring of fire

Answer 8

philippines

Question 9

○ A region of high seismic and volcanic activity in the basin of the Pacific Ocean.

Answer 9

● Pacific Ring of Fire

Question 10

Outlines a series of boundaries where plates collide or move towards each other which create earthquakes and volcanoes.

Answer 10

Pacific Ring of Fire

Question 11

what are trenches

Answer 11

Trenches
○ A long, deep depression which marks the place where plates collide.

Question 12

Plate Tectonic Theory

Answer 12

States that the Earth’s mechanical outer layer (lithosphere) is divided into several
segments called tectonic plates.

Question 13

what is the lithosphere

Answer 13

crust and upper mantle

Question 14

tectonic plates

Answer 14

• segments of Earth’s crusts
• Floats on weak, semi-solid asthenosphere.

Question 15

Asthenosphere

Answer 15

Semi-solid upper mantle

Question 16

○ A proposed mechanism for plate motion
○ Happens in the mantle
○ This causes horizontal movement in the mantle which causes plates to move
towards or away from each other

Answer 16

Convection currents

Question 17

• a method of heat transfer in which cold, dense material sinks while hot, less dense material rises.

Answer 17

○ Convection

Question 18

the process in which when two plates converge, the denser plate
sinks under the other

Answer 18

subduction

Question 19

the boundary where subduction happens

Answer 19

subduction zone

Question 20

○ Oceanic plate (denser) collides with a continental plate (less dense), the oceanic
plate is forced under the continental plate and into the asthenosphere where
magma exists.
○ The addition of large volumes of seawater into the mantle allows faster heating of
mantle rocks into magma.
○ The magma then rises to the overlying continental plate thus forming volcanoes
along the plate margins

Answer 20

subduction / converging plates

Question 21

○ A gap forms between two plates when they move away from each
other.
○ Magma from the mantle forcefully ruses through the gap forming volcanoes
calles ocean ridges.
○ Difficult since it happens in the seabed

Answer 21

Diverging Plates

Question 22

Oceanic plate (denser) collides with a continental plate (less dense), the oceanic
plate is forced under the continental plate and into the asthenosphere where
magma exists.
○ The addition of large volumes of seawater into the mantle allows faster heating of
mantle rocks into magma.
○ The magma then rises to the overlying continental plate thus forming volcanoes
along the plate margins

Answer 22

converging plate or subduction

Question 23

ocean floor volcanoes formed from diverging plates

Answer 23

ocean ridges

Question 24

Volcanic eruptions under the ocean can create an island as the volcanic
materials may solidify above the water surface. Examples?

Answer 24

• Didicas volcanic islands in Cagayan Philippines
• Kavachi submarine Solomon Islands

Question 25

An area in the mantle where rocks melt because of the mantle’s intensified heat. Magma from the hot spot rises to the Earth’s crust, thins it out, fractures it, and forms a volcano in it.

Answer 25

hot spots

Question 26

sides of the volcano; extends to the summit

Answer 26

flanks

Question 27

the apex; highest point of a volcano
Contains the vent

Answer 27

summit

Question 28

mouth of the volcano
Sometimes confused with the caldera - a cauldron or cooking pot-like volcanic feature.

Answer 28

crater

Question 29

found in the summit
An opening that allows magma to be ejected from the volcano
Extends to the conduit

Answer 29

vent

Question 30

the pipe or the channel that conveys the magma.

Answer 30

conduit

Question 31

originate from conduit

Answer 31

Secondary/ branch pipes

Question 32

a large underground pool of molten rocks

Answer 32

Magma chamber/ reservoir-