midterm 2

Question 1

Body waves

Answer 1

pass through earth’s interior

Question 2

p-waves

Answer 2

primary compression waves. Move faster

Question 3

S-waves

Answer 3

secondary waves, vertical sheer motion. Doesn’t travel through liquid

Question 4

moment magnitude

Answer 4

amount of energy released. increases by 31.6E1.5 every step

Question 5

Richter magnitude

Answer 5

amount of shaking 100km from epicenter.
depends on rock type

Question 6

megathrust

Answer 6

large eq (7.9) that occurs at subduction boundries

Question 7

sheer walls

Answer 7

diagonal beams for eq stability

Question 8

how tsunamis form

Answer 8

associated with megathrusts
column of water is suddenly moved upwards and the water displaces outwards

Question 9

1964 Anchorage AK eq

Answer 9

MW 9.2
subduction, shaking for over 4 min
liquefaction caused landslides

Question 10

1960 Chile eq

Answer 10

9.5 MW
tsunami 10-15 min after

Question 11

1946 Hawaii tsunami

Answer 11

from eq in Ak
arrived in HI 5 hr later

Question 12

evidence of past tsunamis

Answer 12

oral tradition from native people
Japanese records
tsunami deposits - can date organic material

Question 13

focus/hypocenter

Answer 13

location of origin beneath the surface

Question 13

focus/hypocenter

Answer 13

location of origin beneath the surface

Question 14

epicenter

Answer 14

location above origin on the surface

Question 15

fault scarp

Answer 15

small step or offset on the ground surface where one side of a fault has moved vertically

Question 16

seismic gap

Answer 16

part of fault where no eq has happened recently and tension is building

Question 17

factors of eq size

Answer 17

how much of the fault ruptured
rock type
depth of rupture

Question 18

braided river

Answer 18

many channels with sand bars in between
moves lots of sediment but not much clay
dry, arid climates; seasonal rain
common coming off glaciers

Question 19

meandering river

Answer 19

snake-like paths
humid, wet climates w/ warm temp
promotes clay formation

Question 20

flood plain

Answer 20

whole area where river travels
filled with deposits from meandering river

Question 21

oxbow lakes

Answer 21

where the river used to meander but doesn’t anymore

Question 22

loval base level

Answer 22

dam or lake

Question 23

ultimate base level

Answer 23

sea level or mouth of river

Question 24

waterfalls

Answer 24

occur at resistant rock layers and create ledges most erosion where it goes off cliff deposition where it drops

Question 25

competence

Answer 25

biggest grain size a river can carry

Question 26

capacity

Answer 26

total sediment the river can carry

Question 27

laminar flow

Answer 27

all water moves in the same direction lower part of stream

Question 28

turbulent flow

Answer 28

water moving in all directions upper part of stream creates white water

Question 29

thalweg

Answer 29

pathway of water with the fastest velocity spiral in meandering rivers

Question 30

traction

Answer 30

boulders at bottom rolling

Question 31

saltation

Answer 31

sand particles bouncing off bottom of river

Question 32

youthful rivers

Answer 32

steep sides, narrow channels

Question 33

middle aged ricer

Answer 33

sloped sides, narrow channels, less narrow than you rivers

Question 34

mature river

Answer 34

wide flood plain, meandering channel

Question 35

rejuvenated river

Answer 35

base level dropped rapidly either tectonic uplift or drop in sea level visible terraces

Question 36

dendritic drainage

Answer 36

nothing controlling the river

Question 37

radial

Answer 37

on something with a central high point ex volcano water flows away from center

Question 38

rectilinear

Answer 38

joins along surface river flows straight along joints with sharp angles

Question 39

trellis

Answer 39

anticlines and inclines with tributaries river cuts across hills

Question 40

lineations

Answer 40

repeated commonly penetrative and parallel alignment often old or active faults

Question 41

superposed stream

Answer 41

stream thought to predate the structures it crosses

Question 42

porosity

Answer 42

voids in rocks

Question 43

permeability

Answer 43

connectivity of the voids

Question 44

primary porosity

Answer 44

spaces between voids

Question 45

secondary porosity

Answer 45

fractures and joints in the rocks

Question 46

aquifer

Answer 46

permeable rock that transports water unconfined - accessible at surface

Question 47

aquiclude

Answer 47

like an aquifer but underground

Question 48

capillary fringe

Answer 48

water on grain surfaces

Question 49

zone of saturation

Answer 49

fills pores in rocks no air pockets, just water

Question 50

streams and rivers

Answer 50

water table comes to sureface

Question 51

groundwater

Answer 51

flows to lover areas of water table

Question 52

velocity of wate

Answer 52

permeability times slope

Question 53

perched water table

Answer 53

local feature where small aquiclude underlies an aquifer

Question 54

artesian wells

Answer 54

ground water pressurized above surface

Question 55

5 affects of coastline appearances

Answer 55

tectonics wave erosion along coasts tides sediment sources climate

Question 56

wave refraction

Answer 56

focuses energy of the wave to one part of the coastline

Question 57

wave formation

Answer 57

waves form as the result of strong winds blowing over water

Question 58

wave break

Answer 58

break at 1/2 wavelength

Question 59

longshore currents

Answer 59

caused by waves approaching shore at angle and moves out parallel

Question 60

spit

Answer 60

sandy landform caused by longshore drift

Question 61

rip current

Answer 61

narrow currents formed form water piling up and rushing back out to the open ocean

Question 62

Bay of Fundy

Answer 62

highest tidal range in the world

Question 63

nature of tides

Answer 63

affects coastal landforms

Question 64

carbonate reefs

Answer 64

often around volcanic islands reef remains after volcano dies

Question 65

estuaries

Answer 65

drowned ricer valley from sea level rise

Question 66

barrier island

Answer 66

constantly evolving deposit of sand parallel to the coast protects coast from hurricanes

Question 67

1884 Charleston

Answer 67

intraplate eq most of the city was destroyed

Question 68

1811-1812 madrid

Answer 68

4 intraplate earthquakes caused by old faults under surface felt far away because rock was cold and old