Geol-111 Volcanoes

Front 1

What famous cinder volcano exists in Mexico?

Back 1

Paricutin

Front 2

Volcanic eruption characterized by an outpouring of lava with a lack of explosive activity:

Back 2

Effusive eruption

Front 3

Which lava compositions have a high amount of silica?

Back 3

Intermediate, felsic (thick /sticky…cool lava)

Front 4

What is Devil’s Tower known for?

Back 4

Its famous columnar joints

Front 5

A low and fairly rounded volcano that is produced by effusive eruptions:

Back 5

Shield volcano (ex: Hawaiian volcanoes, Mauna Loa in Hawaii)

Front 6

Destructive volcanic mudflow that occurs when ash mixes w/ water or snow:

Back 6

Lahar

Front 7

Lava with a smooth ropy surface that cools slightly on the top layer and wrinkles:

Back 7

Pahoehoe (“Twisted braid of rope”)

Front 8

What tectonic plate boundary are most volcanoes associated with?

Back 8

Divergent plate boundaries

Front 9

Effusive eruptions occur in what 2 volcano types?

Back 9

1) shield volcanoes
2) fissure volcanoes

Front 10

Which lava compositions have only a small amount of silica?

Back 10

Ultramafic, mafic (thin/fluid-like…hot lava)

Front 11

A submarine volcano in Hawaii that should appear at the surface in several thousands of years:

Back 11

Loihi

Front 12

What forms in effusive eruptions after flood basalts cool and separate?

Back 12

Columnar joints

Front 13

What happens once a volcano migrates off of a hot spot?

Back 13

It becomes extinct

Front 14

What composition magma is beneath the Mt. St. Helens volcano, and why?

Back 14

Felsic – very sticky magma makes for explosive eruptions

Front 15

Which explosive type of volcano is composed almost exclusively of pyroclastic debris?

Back 15

Cinder cone

Front 16

Volcanic eruption with very hot, fluid-like magma that is ultramafic/mafic in composition and has a low amount of silica:

Back 16

Effusive eruptions

Front 17

What type of volcano is Mount St. Helens classified as?

Back 17

Composite volcano (or stratovolcano)

Front 18

Volcanic eruptions on the sides of mountains:

Back 18

Flank eruptions

Front 19

Which volcano type is the largest of all volcanoes?

Back 19

Composite cones (Stratovolcanoes)

Front 20

Volcanoes that form around the Pacific plate:

Back 20

Pacific Ring of Fire

Front 21

Space within a volcano that fills with magma and builds up pressure over time:

Back 21

Magma chamber

Front 22

Small pyroclastic material that is the size of a sand grain:

Back 22

Volcanic ash

Front 23

Chunky, blocky lava w/ a rough, jagged surface:

Back 23

Aa (“ouch ouch”)

Front 24

What is formed as igneous rocks cool and develop shrinkage fractures in pillar-like fashion?

Back 24

Columnar joint

Front 25

An enlarged volcanic crater:

Back 25

Caldera (1 kilometer)

Front 26

Fast-moving clouds of hot gas and ash that travel down the sides of a volcano:

Back 26

Ash flows (nu’ee ardente)

Front 27

The presence of pillow lava is evidence of what volcanic circumstance?

Back 27

A submarine volcanic eruption

Front 28

What is the only type of volcano that doesn’t build a cone-shaped mountain?

Back 28

Fissure eruption volcano

Front 29

List 2 volcanoes that are located over hot spots:

Back 29

1) All Hawaiian volcanoes
2) Yellowstone volcano

Front 30

What often causes craters to turn into calderas?

Back 30

Sometimes the sides of the crater will cave in, which causes it to increase in size (1 kilometer).

Front 31

What factor primarily controls the viscosity, and therefore the explosiveness, of magma?

Back 31

Silica content, temperature

Front 32

What type of lava serves as great evidence of plate tectonics?

Back 32

Pillow lava

Front 33

An upwelling of abnormally hot rocks within the Earth's mantle that are thought to be the cause of volcanic centers known as hot spots:

Back 33

Mantle plumes

Front 34

What is the most famous set of volcanic arc volcanoes?

Back 34

Cascade Volcanoes (includes Mt. St. Helens and Mt. Rainier)

Front 35

An active composite cone volcano located in Costa Rica:

Back 35

Arenal

Front 36

Large, coarse fragments of pyroclastic debris:

Back 36

Bombs

Front 37

Why do eruptions differ from one another?

Back 37

1) Amount of gas – the more gas in the lava, the more explosive the eruption
2) Viscosity – temperature, silica content

Front 38

What is one of the most famous columnar joints in the world?

Back 38

Devil’s Tower (Wyoming)

Front 39

Which type of volcano has hot fluid-like lava and often erupts from both the top and the sides?

Back 39

Shield volcano

Front 40

Which lava compositions have a high viscosity?

Back 40

Intermediate, felsic (thick /sticky…cool lava)

Front 41

Volcanic eruption that is associated w/ tons of pyroclastic debris, including ash fall, ash flow, and lahars:

Back 41

Explosive eruption

Front 42

Volcano type similar to that of a shield volcano; creates a quiet eruption w/ thin, fluid-like lava flow:

Back 42

Fissure eruption volcano

Front 43

A “glowing cloud” of hot ash flow:

Back 43

Nuée ardente

Front 44

What types of volcanic eruptions produce flood basalts and columnar joints?

Back 44

Effusive eruptions

Front 45

Volcano that is formed from alternating layers of lava & pyroclastic material that are created over a long period of time:

Back 45

Composite cones (stratovolcanoes)

Front 46

When does a crater change into a caldera?

Back 46

When its diameter becomes greater than 1 kilometer

Front 47

What type of volcano is Mauna Loa in Hawaii?

Back 47

Shield volcano

Front 48

A measure of magma’s resistance to flow:

Back 48

Viscosity

Front 49

Points on the Earth’s surface where volcanoes do not appear to be located on plate boundaries:

Back 49

Volcanic hot spots

Front 50

What destroyed the city of St. Pierre during the explosive 1902 eruption of Mount Pele?

Back 50

Nuée ardente (volcanic ash flow)

Front 51

A very steep-sided, symmetrical volcano that forms from an explosive eruption:

Back 51

Cinder cone

Front 52

What is the one of the Cascade Volcanoes that is not a composite cone (stratovolcano)?

Back 52

Mt. Lassen (it is a volcanic dome)

Front 53

What are the 2 types of shield volcano lava flows?

Back 53

1) pahoehoe
2) aa

Front 54

What is the relation between the violence of an eruption and its frequency?

Back 54

Explosive eruptions occur less frequently.
The time between eruptions is considered the "pressure-building" period when gases and vapor pressure builds, resulting in very explosive eruptions.

Front 55

Pyroclastic material that is the size of gravel:

Back 55

Cinders

Front 56

A cone-shaped mountain that erupts lava and pyroclastic material:

Back 56

Volcano

Front 57

Explosive eruptions occur in what 2 volcano types?

Back 57

1) cinder cones
2) composite cones

Front 58

Volcano that forms when a magma chamber never has enough pressure or gas to explode; magma slowly leaks down the tops & sides of the mountain:

Back 58

Volcanic domes (Mt. Lassen)

Front 59

Which lava compositions have a low viscosity?

Back 59

Ultramafic, mafic (thin/fluid-like…hot lava)

Front 60

A circular depression at the top of a volcano; leaves behind a hole:

Back 60

Crater

Front 61

What type of volcanic eruption contains a lot of water and produces large amounts of hot steam?

Back 61

Phreatomagmatic eruptions

Front 62

An active composite cone volcano located in Italy; best known for its 79 A.D. eruption in Pompeii:

Back 62

Mt. Vesuvius

Front 63

The largest pyroclastic material forms when blobs of lava harden in mid-air before falling back down to the earth. These hardened blobs often are one foot or greater in size. What name is given to these features?

Back 63

Volcanic bombs