Vulcanicity

Question 1

Ash fallout

Answer 1

Material <2mm in size ejected vertically from a volcano during an eruption.

Question 2

Acid rain

Answer 2

Rain formed when SO2 from eruptions is absorbed into rainwater and pollutes
the environment below.

Question 3

Caldera

Answer 3

Vast pit crater formed by a violent eruption which blows off the volcano’s
summit. This eruption empties the magma chamber, causing the sides of the
volcano to collapse inwards

Question 4

Composite cones (strato-volcanoes)

Answer 4

Formed from alternating eruptions of ash, tephra and lava, which builds up the
volcano in layers, producing weaknesses that can be exploited by the magma

Question 5

Composite cones (strato-volcanoes)

Answer 5

Formed from alternating eruptions of ash, tephra and lava, which builds up the
volcano in layers, producing weaknesses that can be exploited by the magma

Question 6

Fissure eruptions

Answer 6

When lava escapes through a split or crack in the rock, which can create
extensive lava plateaus

Question 7

Igneous rock

Answer 7

Rocks formed by the cooling of molten magma, either underground (intrusive)
or on the ground surface (extrusive)

Question 8

Lahar (mudflow)

Answer 8

Mudflow composed mainly of volcanic ash mixed with water from a crater lake,
snowmelt, glacier melt or prolonged torrential rain

Question 9

Lava flow

Answer 9

Streams of molten rock that pour or ooze from an erupting vent

Question 10

Nueé Ardente

Answer 10

Another name for pyroclastic flows which have resulted from the collapse of a
lava dome

Question 11

Pyroclastic flows

Answer 11

The result of the bursting of gas bubbles within the magma during a volcanic
eruption. Lava is fragmented and a dense cloud of fragments is thrown out (a
mixture of hot gases, volcanic fragments, ash, and pumice)

Question 12

Shield volcanoes

Answer 12

Shallow-sided and broad volcanoes which are formed by relatively pure basalt
that cools as it runs down from the summit crater

Question 13

Submarine volcanoes

Answer 13

Volcanoes formed beneath the sea (either a single-vent or fissure volcano),
where lava is emitted along a crack in the Earth’s crust (e.g. The Mid-Atlantic
Ridge)

Question 14

Super volcano

Answer 14

A huge volcano that often takes the form of a caldera and is associated with
massive eruptions capable of having a global impact on people

Question 15

Tephra

Answer 15

Pyroclastic material that ranges in size from dust to blocks the size of cars

Question 16

Viscous

Answer 16

A thick and sticky consistency.

Question 17

Volcano

Answer 17

An opening in the earth’s crust through which lava, volcanic ash, and gases
escape.

Question 18

Vulcanicity

Answer 18

The process of molten rock and gases extruding onto the Earth’s surface or
intruding into the Earth’s crust