exam 3

Question 1

seismic waves

Answer 1

generated from the breaking of the earth’s crust (earthquakes) used to learn about the earth’s interior

Question 2

surface waves

Answer 2

move along the outside of the earth

Question 3

body waves

Answer 3

travel through the earth and are changed by the contents of the interior, they are reflected, refracted, or absorbed

Question 4

inner core

Answer 4

solid made of NI and Fe

Question 5

outer core

Answer 5

liquid made of Ni and Fe

Question 6

lower mantle

Answer 6

makes up the most volume, solid made of silica

Question 7

asthenosphere

Answer 7

plastic layer below the crust

Question 8

continental crust

Answer 8

2.7g/mL, 25-50 miles thick

Question 9

oceanic crust

Answer 9

3.0g/mL, 2-4 miles thick

Question 10

mt everest

Answer 10

earths highest point, 29,028ft

Question 11

denali

Answer 11

highest point in North America, 20,320ft

Question 12

challenger deep

Answer 12

lowest point of the Marianna’s trench 36,000ft

Question 13

shrinking earth model

Answer 13

1600s-1900s thought the earth’s topography was formed by decreasing the earth’s volume while keeping the surface area the same; debunked because there are not uniform wrinkles

Question 14

sir francis bacon

Answer 14

proposed continental drift when he noticed the coastlines of the continents look like they would line up in the 1620s

Question 15

alfred wegner

Answer 15

proved the existence of pangea by matching up the rocks and fossils on the coast of Africa and South America in the 1910s

Question 16

Arthur Holmes

Answer 16

proposed sub crustal convection as a mechanism for continental drift requiring a liquid under the crust in the 1930s

Question 17

sonar

Answer 17

used to map the ocean floor topography, first map produced in 1959

Question 18

bathymetry

Answer 18

mapping ocean floor topography

Question 19

direct observation

Answer 19

stronger submarines allowed us to observe ridges and note effusive volcanos along the MORs

Question 20

geography of earthquakes

Answer 20

set up arrays of seismometers in response to the cold war that allowed us to create an earthquake map

Question 21

absolute age dating

Answer 21

of oceanic floor rock via deep sea drilling projects showed that the youngest rocks are around the MOR and older rocks are along the continents

Question 22

glomar ships

Answer 22

used to collect oceanic rocks for absolute age dating

Question 23

first complete map of the earth’s surface

Answer 23

1977

Question 24

Harry Hess

Answer 24

proposed sea floor spreading for creating new oceanic crust in the 1960s

Question 25

subduction

Answer 25

destroys oceanic crust at the coasts, crust is constantly recycled oldest is only 226myo

Question 26

plate tectonics

Answer 26

a number of distinct mappable plates move spatially an average of 6cm a year up to a max of 18cm a year

Question 27

isostacy

Answer 27

vertical bobbing of tectonic plates as the mass of the continents changes

Question 28

divergent boundaries

Answer 28

most occur in the oceans along MOR via sea floor spreading, shallow minor earthquakes

Question 29

east african rift valley

Answer 29

divergent valley on land

Question 30

convergent boundaries

Answer 30

locations where plates collide that differ based on conditions

Question 31

oceanic - continental covergence

Answer 31

subduction of sima under sial creates an oceanic trench and volcanoes on the coast, strong deep earthquakes

Question 32

oceanic - oceanic convergence

Answer 32

one side will slip under the other creating a trench and a volcanic island arch, strong deep earthquakes

Question 33

continental - continental convergence

Answer 33

uplift creates a nonvolcanic mountain range, strong shallow earthquakes

Question 34

transform boundaries

Answer 34

plates slide past each other creating a high volume of earthquakes

Question 35

Hawaii

Answer 35

has a straight volcanic chain in the middle of the ocean contradicting what we know, only the youngest volcano is active

Question 36

mantle plume

Answer 36

isolated body that is hotter than the rest of the asthenosphere and is fixed in place creating a hotspot which makes a weak point in the crust for magma to seap out

Question 37

verbal scale

Answer 37

a sentence for example 1 inch equals 495 miles on the globe

Question 38

bar scale

Answer 38

a measurable representation of map scale

Question 39

representative fraction (RF)

Answer 39

map distance over earth distance representation given as either a ratio or a fraction giving unit to unit conversions

Question 40

features found on all maps

Answer 40

title, northern orientation, scale, source or reference,

Question 41

standard US map

Answer 41

a 7.5 minute topographic quadrangle

Question 42

topographic maps

Answer 42

show the elevation of the earth's surface using contour lines

Question 43

isolines

Answer 43

connect points of equal value on a map

Question 44

closely spaced contour lines

Answer 44

a steep slope

Question 45

widely spaced contour lines

Answer 45

a gentle slope

Question 46

coordinate systems

Answer 46

grid systems that help determine geographic location

Question 47

elevation

Answer 47

vertical distance above msl

Question 48

latitude

Answer 48

based on relative angle to the north star, divided into hemispheres by the equator; lines are called parallels

Question 49

longitude

Answer 49

based on time zones, all meridians converge at the poles, prime meridian and international date line divide the earth

Question 50

Greenwich England

Answer 50

arbitrary point deemed as longitudinal 0, location of the prime meridian

Question 51

distance between degrees of latitude

Answer 51

69 miles

Question 52

1 degree

Answer 52

60 min, 3600s

Question 53

true north

Answer 53

geographic north, 90 degrees latitude, differs from magnetic north

Question 54

magnetic north

Answer 54

point in northern Canada where there is a magnetic pole which wanders over time requiring adjustments to maps

Question 55

magnetic declination

Answer 55

difference between magnetic and true north given in a degree and east or west direction

Question 56

magnetic declination in ship today

Answer 56

11 degrees west

Question 57

pole flip

Answer 57

last occurred 780000 ybp

Question 58

hatchures

Answer 58

represent closed depressions or bowls on a map with hatched contour lines

Question 59

brown on a map

Answer 59

indicates contour lines

Question 60

blue on a map

Answer 60

indicate hydrographic features, contour lines point upstream

Question 61

red and black on a map

Answer 61

transportation routes or buildings

Question 62

purple on a map

Answer 62

map revisions since the previous edition

Question 63

light red on a map

Answer 63

urban areas where buildings are too close together to be mapped individually