Volcano

Question 1

is the process in which magma, which is buoyant than the surrounding rock, rises to the surface and becomes lava.

Answer 1

Volcanism

Question 2

Any vent or built-up mountain where lava, pyroclastic materials, and/or gases erupt

Answer 2

Volcano

Question 3

where lavas erupt, divergent boundaries manifests as

Answer 3

ridges or fissures

Question 4

Melts are produced by

Answer 4

decompression melting

Question 5

the partial melting of the hot asthenosphere due to decreased lithostatic pressure, exerted by the thinned overlying lithosphere

Answer 5

decompression melting

Question 6

Volcanism at divergent boundaries manifest as

Answer 6

mid-ocean ridges (MOR)

Question 7

Divergent boundaries that occur within continental plates are known as, where diverse manifestations of volcanism can occur. This is due to the partial melting of both the crust and the mantle which creates complex variety of features

Answer 7

continental rifts

Question 8

occurs once substances like volatiles and water are added to rocks, resulting in melting into magma.

Answer 8

Flux melting

Question 9

occurs due to the ascent of mantle plumes to the base of the lithosphere

Answer 9

Intraplate volcanism

Question 10

manifests as a chain of extinct volcanoes similar to a conveyor line, with only the youngest volcano being active

Answer 10

Hot Spot volcanism

Question 11

magma accumulates underground in an open space or an area of highly fractured substrat

Answer 11

magma chamber

Question 12

central vent (shaped like a vertical pipe), a flank vent (smaller conduits issuing from a central vent),

Answer 12

conduits

Question 13

are rock sheets that can form from magma when they seep into cracks in rocks

Answer 13

dikes

Question 14

beds of rocks that form as a result of rock formation between layers of older materials

Answer 14

sills

Question 15

end of a pipe-like conduit at the top of the mound

Answer 15

crater

Question 16

Eruptions issuing from flank vents can produce

Answer 16

parasitic cones

Question 17

These domes form when viscous lava cannot flow too far due to the viscosity and cools into a mound.(roughly circular)

Answer 17

Lava dome

Question 18

broad gently-sloping mounds shaped like a soldier’s shield

Answer 18

Shield Volcano

Question 19

They form when low-viscosity basaltic lava is allowed to flow freely from a vent; over time, these flows stack upon each other, forming the volcano.

Answer 19

Shield Volcano

Question 20

are tall, steep, conical mountains

Answer 20

Composite volcanoes or stratovolcanoes

Question 21

They form by the accumulation of various successive erupted materials; differing layers of pyroclastic flows and lava flows

Answer 21

Composite volcanoes or stratovolcanoes

Question 22

are small, steep mounds composed of tephra or volcanic fragments formed by explosive eruptions.

Answer 22

Pyroclastic cones

Question 23

4 most active volcano

Answer 23

Mt. Kanlaon, Mt. Bulusan, Taal Volcano, Mayon Volcano

Question 24

Potentially active

Answer 24

Mount Apo, Cuernos de Negros, Mount Isaro

Question 25

Inactive

Answer 25

Mount Arayat, seven lakes of Laguna

Question 26

Eruptions are considered _______ when they produce lava flows exclusively.

Answer 26

Effusive

Question 27

_______ eruptions produce pyroclastic debris due to the sudden release of built-up pressure. It is usually associated with high gas content and high viscosity magmas.

Answer 27

Explosive

Question 28

are driven by thermal expansion of the dissolved gases in lava

Answer 28

Magmatic eruptions

Question 29

result from the extreme buildup of gases in the magma chamber and conduit

Answer 29

Plinian eruptions

Question 30

are very similar to Vulcanian eruptions, except that they are of greater magnitude

Answer 30

Peléan eruptions

Question 31

result from more viscous lava, which slows down bubble formation and clogs up conduits

Answer 31

Vulcanian eruptions

Question 32

are sustained fissure eruptions, producing curtains of basaltic lava

Answer 32

Icelandic eruptions

Question 33

are the result of the bursting of clumps of gas bubbles at the surface, throwing up clots of lava

Answer 33

Strombolian eruptions

Question 34

produce low-viscosity basaltic lava flows and fountains

Answer 34

Hawaiian eruptions

Question 35

occurs in a shallow body of water, and are usually characterized by strong explosions as a result of magma coming in contact with water

Answer 35

Surtseyan eruption

Question 36

These eruptions are driven by the violent thermal contraction of magma when it interacts with water, resulting in an explosion

Answer 36

Phreatomagmatic Eruptions

Question 37

These are purely steam-driven, caused by the expansion of water into steam when heated by a nearby magma chamber or volcanic source.

Answer 37

Phreatic Eruptions

Question 38

If earthquake magnitudes are measured using the Richter scale, the volcanic counterpart of this scale is

Answer 38

Volcanic Explosivity Index (VEI)

Question 39

he primary products of eruptions are

Answer 39

lavas

Question 40

When cools, lava may form

Answer 40

fine-grained volcanic rock, volcanic glass

Question 41

composition of lavas, along with temperature, determine their physical properties, most notably their _____

Answer 41

viscosity

Question 42

is best measured against the silica content of the lava, with more siliceous or silica-rich melts being more viscous.

Answer 42

Viscosity

Question 43

Lava is extruded as a lava flow, or a moving stream of lava and flows are classified based on _____ content

Answer 43

silica

Question 44

are silica-depleted and very hot, and thus have a very low viscosity when erupted.

Answer 44

Basaltic flow

Question 45

is a low-viscosity flow with wrinkled, billowing, or ropey surfaces.

Answer 45

Pahoehoe

Question 46

More viscous flows produce ___ or broken, rubbly, spiny surfaces.

Answer 46

a'a

Question 47

Interiors of basaltic flows cool more slowly and may contract into well-formed hexagonal columns perpendicular to the flow. This is known as

Answer 47

columnar jointing

Question 48

are said to have intermediate viscosity, and cannot flow as easily as basaltic lava

Answer 48

Andesitic flows

Question 49

do not typically move further than 10 km.

Answer 49

Andesitic flows

Question 50

are the most silica-enriched and have the lowest temperatures

Answer 50

Rhyolitic flows

Question 51

volcanoes eject large quantities of fragmental igneous debris, which accumulate into

Answer 51

volcanoclastic deposits

Question 52

are any volcanic fragments produced directly by eruptions

Answer 52

Pyroclastic debris

Question 53

are thin glass filaments formed when thin lava strands were frozen

Answer 53

Pelé’s hair

Question 54

Glass droplets are also called

Answer 54

Pelé’s tears

Question 55

Erupting lava fountains eject blobs of spatter, which can accumulate into spatter cones and spatter ramparts around a vent or fissure.

Answer 55

random

Question 56

Magma and lava contain dissolved fluids, which are released as _____ during eruptions.

Answer 56

gases

Question 57

can comprise as much as 9% of magma, and contribute to a melt’s viscosity.

Answer 57

Volatiles

Question 58

High-viscosity magmas trap bubbles (known as _______), leading to pressure buildup and eventual explosions.

Answer 58

vesicles

Question 59

is the internal heat of the Earth

Answer 59

Geothermal Energy

Question 60

is a confined area where groundwater transfers heat from a source to a heat sink and is the basis for energy exploitation

Answer 60

geothermal system

Question 61

takes the form of a shallow magmatic intrusion or naturally high geothermal gradients

Answer 61

heat source

Question 62

is the vessel of heat and is what power plants extract to power turbines

Answer 62

geothermal fluid

Question 63

is a volume of permeable rock which stores geothermal fluid and can be exploited at a profit

Answer 63

reservoir

Question 64

Power Plants extract geothermal fluids by drilling into __ the reservoir

Answer 64

production wells

Question 65

The loss of pressure at the surface and the fluid’s temperature turns the fluid into _ ; this _ is used to drive turbines and generate electricity.

Answer 65

steam

Question 66

Used geothermal fluid is cooled and condensed back into the water, which is either dumped at the surface or injected back underground using re-injection wells.

Answer 66

random

Question 67

In the Philippines, the first geothermal plant was a 2.5 kW pilot plant at barrio Cale in __ put up in 1967.

Answer 67

Tiwi, Albay

Question 68

The first commercial plant in operation was the 3MW pilot plant in __.

Answer 68

Tongonan, Leyte

Question 69

At present, the Philippines is the _ largest producer of geothermal power in the world behind the USA, providing 12.2% of the country’s electricity.

Answer 69

second

Question 70

At present, there are eight producing geothermal fields around the country, with 31 service contract areas in pre-development. Producing fields include Makban in Laguna and Quezon; Tiwi, Albay; Bacman in Sorsogon; Tongonan, Leyte; Palinpinon, Negros Oriental; the Northern Negros Geothermal Project on Mt. Kanlaon; Maibarara, Batangas; and Mount Apo in North Cotabato and Davao.

Answer 70

random

Question 71

Advantages

Answer 71

Geothermal energy is an attractive business venture due to its low cost. Geothermal energy is also renewable, relying on the practically limitless heat of the Earth.

Question 72

Disadvantages

Answer 72

Geothermal fluids are pollutants, containing dissolved metals and ions and having higher temperatures. Improper handling may contaminate water tables or surface waters. These fluids contain greenhouse gases such as carbon dioxide and hydrogen sulphide, among others. Power plants require large areas of cleared land for pipelines and drilling rigs. Careless extraction can empty a reservoir. Over-extraction and hydraulic fracturing can generate earthquakes in the vicinity.