Earth Science Unit 2 Test

Front 1

Define an earthquake

Back 1

a vibration of the ground

Front 2

elastic rebound theory

Back 2

if stress is applied to rock, rock undergoes elastic deformation. if enough stress is applied, rock ruptures and energy is released as earthquake vibrations and rock returns to original non stressful state.

Front 3

list the types of seismic waves

Back 3

Primary (p) wave, Secondary (S) wave, Surface Wave

Front 4

how are earthquakes measured

Back 4

mercalli scale, richter scale, moment magnitude scale

Front 5

name various ways that earthquakes can cause damage on the surface of the earth

Back 5

ground shaking, landslides, liquefaction, fires, tsunamis

Front 6

name the 4 primary layers of the earth

Back 6

crust, mantle, outercore, innercore

Front 7

secondary layers of the earth

Back 7

lithosphere- surface (100 km), solid, rigid and brittle

asthenosphere- 100 km-700 km, weak, plastic, gooey, capable of flow

Front 8

describe the theory of plate tectonics

Back 8

Pangea- supercontinent, continental drift by

alfred wegener

Front 9

three types of plate boundaries

Back 9

divergent, convergent, and transform

Front 10

name the geographical locations where the plate boundaries are located

Back 10

divergent- mid atlantic ridge, mid indian ridge, east pacific rise

convergent- cascade mountains, andes mountains

transform- san Andreas fault, pakistan

Front 11

Primary (P) Wave

Back 11

type of seismic wave, propagates via compression and expansion, travels 16000 mph, can travel through all mediums

Front 12

Secondary (S) Wave

Back 12

types of seismic wave, propagates via shearing motion, travels 10,000 mph, only travels through solids

Front 13

Surface Wave

Back 13

type of seismic wave, propagates similar to an S wave, slowest (few 1000 mph), causes most damage

Front 14

Mercalli Scale

Back 14

based on amount of damage the earthquake caused, ranges from I to XII

Front 15

Richter Scale

Back 15

based on amplitude of seismic wave, ranges from 1 to 10. logarithmic scale- for every unit on the scale, intensity increases by 10X, energy increases by 30X, poorly assesses large EQ's

Front 16

Moment Magnitude Scale

Back 16

based on amount of displacement along fault, most accurate to date, best estimates intensity of large EQ's, best estimates energy released, verified in the field

Front 17

Crust

Back 17

outermost, thinnest, two types: continental crust and oceanic crust

continental- up to 70 km composed of felsic

oceanic- 5-6 km thick, composed of mafic igneous rock (basalt)

Front 18

Mantle

Back 18

2900 km thick, composed of peridotite (ultra mafic)

Front 19

Outercore

Back 19

2300 km thick, composed of iron, believed to be liquid

Front 20

innercore

Back 20

1200 km radius, solid very dense, composed of iron and nickel

Front 21

hot spot

Back 21

weak zone in the crust that allows magma to reach the surface (example: hawaii)

Front 22

paleomagnetic evidence of plate tectonics

Back 22

magnetic reversals- show flip flopping of earth's magnetic field and supports divergent plate activity

Front 23

driving mechanism for plate tectonics

Back 23

convection- migration of warm material into cool material

Front 24

features of a volcano

Back 24

mountain formed by extrusion of molten rock, lava

Front 25

types of material expelled during volcanic eruptions

Back 25

pyroclastic material- broken rock fragments classified by size: ash (smallest), lapilli (walnut size), blocks/bombs (largest)

Front 26

three types of volcanoes

Back 26

1.shield: largest, gently sloping slides, composed of basaltic lava

2. stratovolcano: moderate size, moderately sloping sides, composed of pyroclastics and lava

3. cinder cone: smallest, steep sides, composed of pyroclastics

Front 27

features associated with volcanic activity

Back 27

caldera- large depression formed by a collapsed volcano

volcanic neck- erosional remnant of a former volcano

Front 28

major water bodies on the surface of the earth

Back 28

pacific ocean, atlantic ocean, indian ocean, arctic ocean, southern ocean

Front 29

pacific ocean

Back 29

largest ocean, largest geographical feature on earth, 13,000 ft avg

Front 30

atlantic ocean

Back 30

about half the size of the pacific, bounded by almost parallel continent, 12000 ft

Front 31

indian ocean

Back 31

slightly smaller than atlantic but has roughly same average ft, mostly in southern hemisphere

Front 32

arctic ocean

Back 32

only 7% the size of the pacific, 2500 ft avg

Front 33

southern ocean

Back 33

found below 50 degrees south parallel, encircles antarctica, distinguished by changes in temp, salinity and fauna

Front 34

active continental margin

Back 34

associated with plate boundary, EQ's and volcanoes, narrow band of highly disturbed sediment

Front 35

passive continental margin

Back 35

not associated with a plate boundary, little to not EQ's and volcanoes, thick wedge of undisturbed sediment. flat slope

Front 36

mid ocean ridge

Back 36

represent areas of divergence 46000 miles, high compared to rest of ocean floor (volcanic activity pushes surface upward)

Front 37

sea floor sediments

Back 37

terrigeneous, biogeneous, hydrogenous, oil and natural gas, gas hydrates, sand and gravel, manganese nodules