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Flashcards in Lesson 5 Deck (39):
1

Advantages of volcanoes

Serve as a foreign and local tourist attraction

Help improve the quality of the surrounding soil by
providing nutrients for crops.

Their geothermal component is also an excellent source
of energy and recreational facilities.

2

Disadvantages of volcanoes

Pose a threat on the communities surrounding the volcano

Bury adjacent communities in lahar and affect global climate

People living in areas distant from the site can also be affected by
the ash fall, poisonous gases, and lahar.

3

a vent on the earth’s surface that opens
downward to a pool of molten rock, debris, and gases. Its
formation involves the process of subduction.

volcano

4

takes place when two plates converge.

subduction

5

the place where the two plates
converge and the volcano is formed (DOST-PHILVOCS,
n.d.).

subduction zone

6

The thickness of the magma caused by____makes it difficult for gases to be released easily.

silica content

7

forms inside the steep cone and this
collects the gases.

magma chamber

8

When the_____accumulate, the volcano erupts because
the pressure rises within the chamber as it cannot contain
the magma.

gases

9

can harm people and surroundings.

erupts explosively, expels lava, rocks, ash, and gas

10

The occurrence of ____(4)is also possible.

earthquake, lahar flow, debris,
avalanche, or tsunami

11

large underground pool of magma

magma chamber

12

it is magma, yet this is the term once it reaches the surface

lava

13

bowl-shaped basin in the top of the volcano

crater

14

central tube which magma travels through

vent

15

eruptions from other vents may build up_____on the flanks

secondary cones

16

materials thrown out by the volcano

ash, steam and gas

17

larger materials thrown out by the force of eruption

volcanic bombs

18

are steep-sided and cone-shaped,
made up of layers of ash and lava
and containing sticky lava which
doesn't flow very far.

composite volcanoes

19

have gently sloping sides and
runny lava that covers a wide
area. Gases escape very
easily from shield volcanoes.

shield volcanoes

20

currently erupting or is showing signs of
eruption. Have erupted within the last 600 years.

active

21

has erupted and then entered a
long period of inactivity.

potentially active

22

has not shown any sign of activity for a long
period of time. Has no record of volcanic eruption in the
past thousand years.

inactive

23

volcanic eruption hazards

lava flow
pyroclastic flow
tephra falls
ballistic projectiles
volcanic gas
lahar

24

mass of magma that flows down the slope
of the volcano at a rate of 3 km/d (slightly high viscosity)
or 45 km/h (low viscosity).

lava flow

25

hot dry masses of fragmented
volcanic materials that move along a slope and in contact
with ground surface at a speed greater than 60 km/h.

pyroclastic flow

26

showers of fine to coarse-grained
volcanic materials and other airborne products of volcanic
eruption.

terphra falls

27

rocks that are released into
the air by an erupting volcano.

ballistic projectiles

28

one of the basic components of
magma or lava.

volcanic gas

29

flowing mixture of volcanic debris and water.

lahar

30

is the downward movement of soil, rocks, and
earth materials along a slope.

landslide

31

is a slow or gradual
movement of soil

creep

32

is the downslope flowage of
soft and unconsolidated materials.

slump

33

is the slow
to rapid downslope movement of
unconsolidated soil and rock
details.

Rock and debris slide

34

is the free falling
movement of massive rocks from a
cliff or steep slopes.

rock fall

35

is the rapid flowage of
debris and other rock materials.

debris flow

36

is the mass movement
characterized by a flowing mass of
mud along the flank of a volcano.

mud flow

37

Geologic formations caused by exposure to water, erosion,
and ground movement.

sinkholes

38

usually formed by erosion of bedrocks
composed of soft minerals and rocks such as salt, gypsum,
limestone, dolomite, and other materials that belong to the
evaporate or carbonate classes of rocks.

sinkholes

39

Acid water underground and rainwater dissolve the rocks
and form underground passage for water called

conduits