DRRR Earthquake and Volcano

Question 1

Earthquake is also known as

Answer 1

quake; tremor; temblor

Question 2

the perceptible shaking of the surface
of the Earth, resulting from the sudden release of
energy in the Earth’s crust that creates seismic
waves

Answer 2

Earthquake

Question 3

Geologists explain that an earthquake is a type of
hazard that depends on the strength of ________

Answer 3

seismic activity

Question 4

A large earthquake will always be followed by a
sequence of ___________ that normally aggravates its
effect on human and material elements like buildings
and infrastructure

Answer 4

aftershocks

Question 5

Potential Earthquake Hazards

Answer 5

1. Ground Shaking/ Ground Motion
2. Ground Rupture
3. Liquefaction
4. Earthquake-induced landslides
5. Tsunami

Question 6

(E. Hazard)*If an earthquake generates a large enough shaking intensity, structures like buildings, bridges, and dams can be severely damaged, and cliffs and sloping ground destabilized.
* Perched or stacked objects may fall and injure or bury anyone close by.

Answer 6

Ground Shaking or Ground Motion

Question 7

the visible breaking and displacement
of the Earth’s surface along the trace of a fault.
*Any structure built across the fault is at risk of being
torn apart as the two sides of the fault slip each other

Answer 7

Ground Rupture

Question 8

occurs when waterlogged sediments
are agitated by seismic shaking. This separates the
grains from each other, reducing their load-bearing
capacity

Answer 8

Liquefaction

Question 9

(E. Hazard) * Buildings and other structures can sink down into the ground or tilt over, whilst underground pipes and tanks may rise up to the surface.

Answer 9

Liquefaction

Question 10

When the vibrations stop during liquefaction what happens after

Answer 10

the sediments settle down
again, groundwater is squeezed out of cracks and
holes in the ground cause flooding.

The aftermath of liquefaction can leave large areas
covered in a deep layer of mud.

Question 11

more commonly known as a
landslide, is the downslope movement of rocks or
sediments under the influence of gravity.

Answer 11

Mass wasting

Question 12

It is a process that follows weathering and can have particularly devastating effects like floods, blocking of rivers, death, and damage to land and natural resources.

Answer 12

Landslides

Question 13

ocean waves triggered by earthquakes that
occur near or under the ocean, volcanic eruptions,
submarine landslides, or onshore landslides in which
large volumes of debris fall into the water

Answer 13

Tsunami

Question 14

The damage and destruction from tsunamis depend on

Answer 14

• the degree of flooding,
• wave impact on structures, and
• erosion

Question 15

Natural Signs of Impending Tsunami

Answer 15

1. Animal Behavior
2. Drawback

Question 16

▪Some zoologists hypothesize that some animal species like elephants have the ability to sense ________ from an earthquake or a tsunami.
▪If correct and substantiated with more evidence,
monitoring their behavior could provide advance
warning of earthquakes and tsunamis

Answer 16

subsonic Rayleigh waves

Question 17

In Sri Lanka
Elephants….
Dogs….
Flamingos….
Zoo animals….

Answer 17

• Elephants screamed and ran for higher ground.
• Dogs refused to go outdoors.
• Flamingos abandoned their low-lying breeding
  areas.
• Zoo animals rushed into their shelters and could
  not be enticed to come back out.

Question 18

is when the ocean recedes from land before a
tsunami strikes.

Answer 18

drawback

Question 19

If the first part of a tsunami to reach the coast is a trough, rather than a wave crest, the water along the shoreline is

Answer 19

dragged back dramatically, exposing parts of the shore that are normally underwater and stranding many marine creatures

Question 20

highest point of the wave

Answer 20

crest

Question 21

lowest point of the wave

Answer 21

trough

Question 22

DIFFERENT EARTHQUAKE
HAZARD MAPS

Answer 22

1. Natural Hazard Risks Map
2. Earthquake-Induced Landslide Susceptibility Map
3. Seismic Hazard and Structures in the Philippines
4. Floods and Landslides Hazard Map
5. Ground Shaking Hazard Map

Question 23

Volcano-Related Hazards

Answer 23

1. Lahars
2. Ash Fall
3. Pyroclastic Flows
4. Volcanic Gases
5. Lava Flows
6. Ballistic Projectiles

Question 24

an Indonesian word describing a
mudflow or debris flow that originates on the
slopes of a volcano

Answer 24

Lahar

Question 25

masses of rock, mud, and water that travel rapidly downslope and downstream under the action of gravity

Answer 25

Lahar

Question 26

Lahars can form in a number of situations, namely,

Answer 26

1. when small slope collapses gather water on their way down a volcano, 2. through rapid melting of snow and ice during an eruption, 3. from heavy rainfall on loose volcanic debris, 4. when a volcano erupts through a crater lake, or 5. when a crater lake drains because of overflow or wall collapse

Question 27

Destructive Characteristics of Lahars

Answer 27

1. Lahars moved rapidly down valleys like rivers of concrete. 2. Lahars can occur with or without a volcanic eruption. 3. Lahars pick up material as they travel, which can cause damage to structures in their path. 4. Lahars and excess sediment cause serious economic and environmental damage to river valleys and flood plains

Question 28

consists of fragments of pulverized rock, minerals, and volcanic glass created during volcanic eruptions and measuring less than 2 mm in diameter.

Answer 28

Volcanic Ash

Question 29

used to refer to all explosive eruption products, referred to as tephra, including particles larger than 2 mm.

Answer 29

Volcanic Ash

Question 30

formed during explosive volcanic eruptions when dissolved gases in magma expand and escape violently into the atmosphere

Answer 30

Volcanic Ash

Question 31

Devastating Effects of Ash Fall

Answer 31

- As a result of its fine-grained abrasive character and widespread distribution by wind, ash fall and volcanic ash clouds are a major hazard to aviation - Ash fallout to the ground can pose significant disruption and damage to buildings, transportation, water and wastewater, power supply, communications equipment, agriculture, - fine-grained ash, when ingested can cause health impacts to humans and animals

Question 32

a dense, fast-moving flow of solidified lava pieces, volcanic ash, and hot gases.

Answer 32

Pyroclastic Flows

Question 33

A pyroclastic flow is extremely hot, burning anything in its path. It may move at speeds as high as

Answer 33

200 m/s

Question 34

Most pyroclastic flows consist of two parts:

Answer 34

- lower (basal) flow of coarse fragments that moves along the ground, and a - turbulent cloud of ash that rises above the basal flow

Question 35

Pyroclastic flows form in different ways:

Answer 35

1. Collapse of Eruption Column 2. Boiling Over from eruptive vent 3. Collapse of Lava Domes/Flow

Question 36

during a highly explosive eruption, the column ejected upwards into the atmosphere cools and can become too cool and dense to maintain upward momentum.

Answer 36

Collapse of eruption column

Question 37

during explosive eruption, material is erupted without forming a high plume and rapidly moves down slope

Answer 37

“Boiling over” from eruptive vent

Question 38

the fronts of lava flows or domes can become so steep that they collapse due to gravitational force

Answer 38

Collapse of lava domes or flows

Question 39

release of __________ is one of the most common volcanic activities that occur before, during, and after eruptions

Answer 39

volcanic gases

Question 40

are composed of different materials depending on its location

Answer 40

Volcanic Gases

Question 41

Volcanic Gases are composed of

Answer 41

- Water vapor and carbon dioxide typically make up the bulk composition of volcanic gases, followed by sulfur dioxide. - hydrogen chloride, and hydrogen fluoride

Question 42

Negative Impacts of Volcanic Gas (Sulfur Dioxide, Co2, Hydrochloric acid)

Answer 42

1. Sulfur Dioxide - form into sulfuric acid which is a component of acid rain; and * direct contact with sulfur dioxide can irritate the eyes, cause skin rash, and poison the respiratory system 2. Carbon dioxide in high concentrations can cause asphyxiation without warning because of the gas’ odorless and colorless nature 3. Volcanic gases also help in reflecting the heat outside Earth creating an albedo effect. 4. Hydrochloric acid helps in the degeneration of the ozone layer.

Question 43

streams of molten rock that pour or ooze from an erupting ven

Answer 43

Lava Flows

Question 44

erupted during either non-explosive activity or explosive lava fountains

Answer 44

Lava

Question 45

speed of which lava moves across the ground depends on several factors including:

Answer 45

1. type of lava erupted and its viscosity; 2. steepness of the ground over which it travels; 3. whether the lava flows as a broad sheet, through a confined channel, or down a lava tube; and 4. rate of lava production at the vent

Question 46

Negative Impacts of Lava Flows

Answer 46

- Lava flows can crush and bury structures and livelihoods. They solidify over time making the areas buried by the lava useless. - Lava flows also burn surroundings because of its intense heat. Flammable resources such as wood, plants, and houses can get caught on fire as lava flows along their path.

Question 47

rocks that an erupting volcano may hurl into the air. * These blocks and bombs travel like cannonballs and usually land within 2 km of the vent.

Answer 47

Ballistic Projectiles

Question 48

These events may occur without warning and in the absence of a larger magmatic eruption; limited to within about 5 km of vents

Answer 48

Ballistic Projectiles

Question 49

Devastating Effects of Ballistic Projectiles

Answer 49

Ballistic projectiles endanger life and property by: 1. the force of impact of falling fragments, but this occurs only close to an eruption; 2. loss of agricultural lands if burial is greater than 10 cm depth; 3. tephra falls can carry harmful and poisonous particles and gases; 4. producing suspensions of fine-grained particles in air and water which clogs filters and vents of motors, human lungs, industrial machines, and nuclear power plants; and 5. burial of tephra can collapse roofs of buildings, break power and communication lines and damage or kill vegetation

Question 50

* Erupted within historical times (within the last 600 years), accounts of these eruptions were documented by man erupted within the last 10,000 years based on the analyses of material from young volcanic deposits.

Answer 50

Active Volcanoes

Question 51

Active Volcanoes in the Philippines

Answer 51

1. Babuyan Claro 2. Banahaw 3. Biliran (Anas) 4. Bud Dajo 5. Bulusan 6. Cabalian 7. Cagua 8. Camiguin de Babuyanes 9. Didiccas 10. Hibok-hibok 11. Iraya 12. Iriga 13. Isarong 14. Kanlaon 15. Leonard Kniaseff 16. Makaturing 17. Matutum 18. Mayon 19. Musuan (Calayo) 20. Parker 21. Pinatubo 22. Ragang 23. Smith 24. Taal

Question 52

Signs of Impending Volcanic Eruption

Answer 52

1. various types of warnings before eruptions begin. - Steam-blast eruptions could occur with little or no warning as superheated water flashes to steam. - Magmatic eruptions involve rise of magma toward the surface 2. People living near volcanoes may detect premonitory events before an eruption * Both the frequency of occurrence and intensity of felt earthquake commonly increase before eruptions begin. * Eruptions may also be preceded by noticeable steaming or fumarolic activity * Swelling of the ground surface can be detected by using precision instruments and techniques that measure minute changes in slope, distance, or elevation at the ground surface 3. Measurement of Changes in Heat Flow * Measurement of changes in heat flow at a volcano by repeated infrared surveys or by direct measurements of hot spring or fumarole temperatures. * Changes in the composition or relative abundances of fumarolic gases ma also precede eruptions and can be detected by frequent or continuous analysis of gases 4. Detection and Interpretation of Precursory Events * Precursors to volcanic activity may continue for weeks, months, or even years before eruptive activity begins, or they can subside at any time and not be followed by an eruption * Monitoring of volcanic precursors may provide a general warning that volcanic activity in a specific area is becoming more likely, but it often does not pinpoint the nature or timing of an eruption or even its certainty