Volcanic Hazards

Question 1

Composite Volcano

Answer 1

Large, steep-sided, symmetrical, cone-shaped volcano.

Formed from alternating layers of lava flows, volcanic ash, cinders, blocks and bomb.

Question 2

Lahars

Answer 2

Mudflows composed of pryoclastic material and water that flows down from a volcano, usually in along a river valley.

Question 3

Magma

Answer 3

Molten rock that is found beneath the surface of the earth.

Question 4

Pyroclastic Flow

Answer 4

A high density mass of gases, hot ash and larger material that flows rapidly down the sides of the volcano.

Question 5

Tephra

Answer 5

Any type of rock fragment that is forcibly ejected from a volcano during an eruption.

Question 6

Tsunamis

Answer 6

Generated by shallow-focus underwater earthquakes, violent volcanic eruptions, underwater debris slides and landslides into the sea.

Question 7

Volcanic bombs

Answer 7

Rocks that are more than 5mm in diameter that are thrown into the air by a volcanic eruption.

Question 8

Volcanic explosion index

Answer 8

A scale used to measure the explosiveness of volcanoes.

Question 9

Ash

Answer 9

Dust-sized particles of rock produced by the explosive eruption of some volcanoes.

This material may be carried in the air for long distances from the volcano which formed it.

Question 10

Constructive plate boundary

Answer 10

Also known as divergent - the plates are moving apart .

Question 11

Destructive plate boundary

Answer 11

Also know as convergent - Usually involves oceanic plate and continental plate, as the plates move together earthquakes can be caused.
On collision the oceanic plate is forced beneath the continental plate, this is known as subduction.

Question 12

Primary effects

Answer 12

Brought about by material ejected from the volcano.

Question 13

Primary effects (listed)

Answer 13

Tephra
Pyroclastic flows
Lava flows
Volcanic gases

Question 14

Secondary effects (listed)

Answer 14

Lahars
Flooding
Volcanic landslides
Tsunamis
Acid rain
Climate change