Natural Disasters Exam 2

Front 1

What are tektites?

relation to K/T extinction event?

Back 1

small, glassy spheres
- only produced by meteorites
- found in clay layer

Front 2

What is iridium?

relation to K/T extinction event?

Back 2

Chemical found in trace elements
- found in clay layer

Front 3

What is shocked quartz?

relation to K/T extinction event?

Back 3

structure of quartz that has been skewed (associated with meteorites)
- found in clay layer

Front 4

In what way are the Deccan and Siberian flood basalt provinces related to mass extinction events? Which related to K/T, which related to permian(the greatest mass extinction event of all time)?

Back 4

- extreme amounts of lava flow on land
- Deccan: K/T
- Siberian: Permian

Front 5

What is the anti-podal hypothesis?

Back 5

Energy of impact resonated across and through the earth, cracking lithosphere: resulting in mall basalt eruption

Front 6

What geologic time unit (Eon, Era, Period, Epoch) represents the greatest expanse of geologic time?

Back 6

EON
(order from greatest to smallest: eon, era, period, epoch)

Front 7

What is the Era of Ancient Life called?

Back 7

Paleozoic Era

Front 8

What is the Era of Middle Life called?

Back 8

Mesozoic Era

Front 9

What is the Era of Recent Life called?

Back 9

Cenozoic Era

Front 10

What is the age of the Dinosaurs?

Back 10

Mesozoic Era

Front 11

What is the age of Mammals called?

Back 11

cenozoic era

Front 12

Meteor Crater

Back 12

- Arizona
- Crater: 1.2 km
- youngest most prestine impact crater
- impact of iron meteorite ~50,000 years ago
- studied by Eugene Shoemaker (first to recognize in 1957)
- meteorite diameter: about 100 meters

Front 13

Contributions of Eugene Shoemaker:

Back 13

- studied meteor crater
- was first to recognize it as impact crater
- set up space watch program: system to identify near earth objects

Front 14

Contributions of Walter and Louis Alvarez:
- what did walter find at K/T boundary?

Back 14

- wanted to find K/T boundary in rocks
- identified globally extensive clay layer
- at boundary (in italy where only canyon with K/T extinction visible) he found 1-2 cm of clay with trace elements of iridium and then found clay layer EVERYWHERE, suggested K/T extinction from meteorite

Front 15

What are the three magma types?

Back 15

Mafic
Intermediate
Felsic

Front 16

What rocks do specific types of magma produce?
- Mafic

Back 16

- intrusive igneous rock (course): Gabbro
- extrusive volcanic rock (fine): Basalt

Front 17

What rocks do specific types of magma produce?
- Intermediate

Back 17

- intrusive igneous rock (course): Diorite
- extrusive volcanic rock (fine): Andesite

Front 18

What rocks do specific types of magma produce?
- Felsic

Back 18

- intrusive igneous rock (course): Granite
- extrusive volcanic rock (fine): rhyolite

Front 19

Which is more viscous, a basaltic (mafic) magma or a rhyolitic (felsic) magma?

Back 19

rhyolitic (felsic) magma

Front 20

Define viscosity:

Back 20

ability of substance to resist flow
- more silicon and oxygen in magma = greater viscosity

Front 21

Know the relationship between viscosity and the explosive potential of an eruption.

Back 21

higher viscosity=higher explosivity

Front 22

Is a basaltic magma more explosive or less explosive than a rhyolitic magma?

Back 22

less

Front 23

Are lava flows more likely to be composed of rhyolite or basalt (think about their viscosity)

Back 23

basalt because they have a lower viscosity (ability to resist flow)

Front 24

Is a lava dome generally composed of lava with a low viscosity, or a high viscosity? -low gas content or a high gas content?

Back 24

-high viscosity
-low gas

Front 25

What is A'a lava?

Back 25

rugged, jagged and sharp (higher viscosity) (basaltic)

Front 26

What is pahoehoe lava?

Back 26

smooth, billowy, and ropey (basaltic)

Front 27

What is pillow lava?

Back 27

formed when lava emerges in or underwater (basaltic)

Front 28

What is a lava tube?

Back 28

hardened lava insulating liquid magma and will never cool and crystallize until comes to surface

Front 29

What is obsidian?

Back 29

volcanic glass: glassy texture rock with no crystals; pure volcanic gas

Front 30

What is pumice?

Back 30

vesicular texture: frozen gas bubbles in solid rock

Front 31

What are vesicles?

Back 31

bubbles formed from gas

Front 32

Three types of tephra fragments and sizes

Back 32

1. ash: < 2mm
2. lapilli: 2-64 mm
3.blocks and bombs: > 64 mm
(blocks: never magma)(bombs: large blobs of magma)

Front 33

3 types of catastrophic phenomenon:

Back 33

1. pyroclastic falls
2.pyroclastic flows
3. lahars

Front 34

catastrophic phenomenon
- pyroclastic falls:

Back 34

pyroclastic material in eruptive air collumn (ex: british airways 9, pyroclastic falls reason why they couldn't land)

Front 35

catastrophic phenomenon
- pyroclastic flows:

Back 35

mixture of gasses and pyroclastic material
- force of gasses not strong enough to keep material in air
- collumn collapses onto volcano and begins to flow
why dangerous? 1- exceptionally hot!! 2- toxic gases 3. high velocity

Front 36

catastrophic phenomenon
- lahars:

Back 36

volcanic mudflows (river of wet concrete)
- upper temperature of 100 celcius

Front 37

Which catastrophic phenomenon played a greater role in destruction of: POMPEII

Back 37

pyroclastic fall (ash in particular)

Front 38

Which catastrophic phenomenon played a greater role in destruction of: HERCULANEUM

Back 38

pyroclastic flow

Front 39

Which catastrophic phenomenon played a greater role in destruction of: ST. PIERRE

Back 39

pyroclastic flow

Front 40

Which catastrophic phenomenon played a greater role in destruction of: ARMERO

Back 40

lahars

Front 41

Which village was destroyed by the eruption of: MT. PELE

Back 41

St. Piere

Front 42

Which village was destroyed by the eruption of: NEVADO DEL RUIZ

Back 42

Armero

Front 43

Which village was destroyed by the eruption of: MT. VESUVIUS

Back 43

pompeii and herculaneum

Front 44

What is a volcanic vent?

Back 44

opening exposed on the Earth's surface where volcanic material is emitted

Front 45

What is a parasitic cone?

Back 45

cone shaped accumulation of volcanic material cause by a flank eruption

Front 46

What is a fumarole?

Back 46

vent openings where volcanic gasses are released

Front 47

What is the most abundant volcanic gas?

Back 47

water vapor

Front 48

three general types of volcanoes

Back 48

1. shield volcanoes
2. scoria (cinder) cone
3. stratovolcanoes (composite cones)

Front 49

Shield Volcanoes

Back 49

- shape: very gentle slopes
- a few thousand meters above sea level and a few thousand below also
- low viscosity
- 100% basalt lava
- low explosivity
-EX: mauna loa, Hawaii (height: 9,000)
-lava flow?

Front 50

Scoria (cinder) cone

Back 50

- avg. height: 300 meters
- composition: 100% basalt tephra
- cone also composed of basalt tephra
- straight/steep sides/ large summit crater
- most common/ smallest type
-EX:Paricutin, Mexico
- small pyroclastic eruption?

Front 51

stratovolcanoes (composite cones)

Back 51

- small summit crater
- most explosive (plinian eruption)
- high viscosity
- andesite tephra & lava
- classic shape with alternating layers
-lava dome
- caldera (ex: crater lake)
- EX: Mt. Ranier, Washington

Front 52

What is Spreading Center Volcanism?

Back 52

- occurs as mid oceanic ridge (divergent plates)
- avg. composition: basalt magma
- as plate pulls apart, hot asthenosphere rises to fill voids in lithosphere

Front 53

What is Subduction Zone Volcanism?

Back 53

EX: andes, alucian islands
- convergent plates
- avg composition: andesite (although can produce all)
- must have trench
- "ring of fire" (pacific ring=most active on earth)
- most deadly and violent

Front 54

What is Intraplate (hotspot) volcanism?

Back 54

EX: hawaii
- avg. composition: basalt
- hot mantle plum: melts at top of plume and feeds eruption
-hotspot

Front 55

What direction do the hawaiian and emperor volcanic chains become younger?

Back 55

younger: to the southeast
older: to the northwest