Geol107 Study Guide Part 2

Front 1

What are the excesses in Evaporation v. Precipitation for oceans?

Back 1

more evaporation than precipitation so oceans drying up

Front 2

What are the excesses in Evaporation v. Precipitation for lands?

Back 2

more precipitation than evaporation so land flooded by water
equilibrium exists between 2 excesses

Front 3

What balances these excesses?

Back 3

Surface runoff (as rivers/streams & ground water) of excess precipitation over land is equivalent to excess amount of evaporation over oceans -- keeps ocean at same level & balances the excess of evaporation & precipitation
(except for effects of changing global climate)

Front 4

PATTERNS OF RIVER DRAINAGE
Rectangular

Back 4

rivers/streams bend/curve at nearly right angles, created when rivers/streams flow along FRACTURES OR JOINTS IN ROCKS

Front 5

PATTERNS OF RIVER DRAINAGE
Trellis

Back 5

rivers and tributaries flow parallel to each other for long distances, occurs when rivers flow in valleys of FOLDED ROCKS

Front 6

Longitudinal Profile

Back 6

Decreases from head to mouth

Front 7

How does the longitudinal profile of a river or stream change from its headwaters to its mouth?

Back 7

Discharge: amount of water flowing past a given point in a given amount of time INCREASES FROM HEAD TO MOUTH

Front 8

How are point bars formed?

Back 8

INSIDE: lower velocity,
deposition occurs

Front 9

How are oxbow lakes formed?

Back 9

Erosion occurs, (abandoned meanders in rivers/streams)

Front 10

Natural Levee

Back 10

Deposits that occur along banks of rivers/streams created DURING FLOODS when river/stream overflows its banks (VELOCITY DECREASES outside of channel, lower competence)

Front 11

How can you determine interval floor floods?

Back 11

X-year floods: refers to it is probably that only once in the next X-years will a flood w/ a discharge = or > the flood occur again (probable not certain)

Front 12

Delta

Back 12

Deposits that occur when river/stream flows INTO STANDING BODY OF WATER (lakes or ocean) velocity of river/stream is decreased to 0

Front 13

Aquiclude

Back 13

Material through which water cannot easily flow
Ex. Shale – LOW PERMEABILITY

Front 14

Water Table

Back 14

Boundary between ZONE OF AERATION andZONE OF SATURATION

Front 15

Perched Water Table

Back 15

When, due to LENS OF SEDIMENT ACTING AS AQUICLUDE, a secondary water table is created ABOVE MAIN WATER TABLE

Front 16

How fast does groundwater move?

Back 16

Slowly, typically in CENTIMETERS

Front 17

Cone of Depression

Back 17

Local lowering of water table around well

Front 18

What conditions lead to an artesian well?

Back 18

1) Confined aquifer (an aquifer between two aquicludes)
2) Confined aquifer is inclined
3) Recharge area above height of well

Front 19

How are caves formed?

Back 19

GROUNDWATER as flows through subsurfaces if it encounters limestones it will leach the rock

Front 20

Stalactites

Back 20

Deposits formed on top of caves

GROUNDWATER

Front 21

Stalagmites

Back 21

Deposits formed on floor of caves

GROUNDWATER

Front 22

Sinkholes

Back 22

Collapse where limestone has dissolved away

GROUNDWATER

Front 23

Karst Topography

Back 23

Irregular shaped mountains with intervening valleys

GROUNDWATER

Front 24

Salt-Water encroachment

Back 24

Salt water replaces fresh water

COASTAL AREASG

Front 25

How does Salt-Water encorachment occur?

Back 25

Groundwater is withdrawn from wells

Front 26

What are the typical amounts of dissolved material in potable groundwater?

Back 26

PPM-PPB

Front 27

What are the sources of groundwater contamination?

Back 27

Old landfills, septic tanks, waste lagoons, chemical storage tanks, pesticides, salts on roads

Front 28

What percentage of the earths surface is presently covered by glaciers?

Back 28

10%

Front 29

How a glacier moves?

Back 29

1) Downhill
2) Internal flow
3) Basal slip
4) Crevasses

Front 30

How fast does a glacier flow?

Back 30

1 meter per day

Front 31

What is the competence of ice when compared to water?

Back 31

Competence of ice is huge

Front 32

What is the capacity of ice when compared to water?

Back 32

capacity ice is huge

Front 33

Erosional features of valley glaciers
Striations

Back 33

Scratches and grooves gouged in rocks as ice passes

3) Horns-
Triangular to pyramidal shaped mountain peaks caused by glacial erosion on all sides
4) Arêtes-
Sharp, razor-edge, ridges of rock caused by glacial erosion

5) U-shaped valleys-
Glacial ice moving downhill erodes large amounts of rock, glacial erosional features
6) Hanging valleys-
Elevated glacial valleys where former glacier tributaries entered a main glacial valley
7) Fjords-
glacial valleys that are flooded by seawater

Front 34

Erosional features of valley glaciers
Cirques

Back 34

Bowl shaped depression, located at source area of glacier

Front 35

Erosional features of valley glaciers
Horns

Back 35

Triangular to pyramidal shaped mountain peaks caused by glacial erosion on all sides

Sharp, razor-edge, ridges of rock caused by glacial erosion

5) U-shaped valleys-
Glacial ice moving downhill erodes large amounts of rock, glacial erosional features
6) Hanging valleys-
Elevated glacial valleys where former glacier tributaries entered a main glacial valley
7) Fjords-
glacial valleys that are flooded by seawater

Front 36

Erosional features of valley glaciers
Aretes

Back 36

Sharp, razor-edge, ridges of rock caused by glacial erosion

Front 37

Erosional features of valley glaciers
U-Shaped valley

Back 37

Glacial ice moving downhill erodes large amounts of rock, glacial erosional features

Front 38

Erosional features of valley glaciers
Hanging Valley

Back 38

Elevated glacial valleys where former glacier tributaries entered a main glacial valley

Front 39

Erosional features of valley glaciers
Fjords

Back 39

glacial valleys that are flooded by seawater

Front 40

Depositional features of valley glaciers
Drift

Back 40

All sediment of glacial origin found anywhere on land or seafloor

Front 41

Depositional features of valley glaciers
Till

Back 41

Drift deposit from melting of ice, heterogeneous mixture of particle sizes, not layered by grain size

Front 42

Depositional features of valley glaciers
Outwash

Back 42

Drift deposits from meltwater flowing away from glaciers, layered by grain size (big on bottom, small on top)

Front 43

Depositional features of valley glaciers
Moraines

Back 43

Lateral, Medial, Terminal, Ground

Ridges of till

Front 44

Depositional features of valley glaciers
Drumlins

Back 44

Smooth, elongated ridges of till, orientation tells direction of ice movement

Front 45

Depositional features of valley glaciers
Eskers

Back 45

Sinuous ridges of sand and gravel – deposited by glacial meltwater flowing beneath the ice

Front 46

Depositional features of valley glaciers
Varves

Back 46

Cyclical layers of sediment deposited on seasonal basis (two a year) in glacial lakes

Front 47

Moraines

Back 47

Lateral, Medial, Terminal, Ground

Ridges of till

Front 48

Lateral Moraine

Back 48

Till along side of glacial valley

Front 49

Medial Moraine

Back 49

Formed where two glacial valleys are joined, occur within ice of glacier

Front 50

Terminal Moraine

Back 50

End moraine that marks furthest position of glacial advance

Front 51

Ground Moraine

Back 51

Random till

Front 52

What happens to sea level during glacial times?

Back 52

Surface runoff decreases (water tied up in ice) –
global sea level DECREASES

Front 53

What happens to sea level during interglacial times?

Back 53

Surface runoff increases (water tied up in ice melts and returns to oceans – also warmer ocean expands, greater ocean volume) –
global sea level INCREASES

Front 54

What are some of the proposed causes for long-term fluctuations in climate?

Back 54

Plate Tectonics

Front 55

What are the Milankovitch cycles?

Back 55

Changes in earths revolution about sun and changes in earth’s rotational axis

Front 56

3 major Milankovitch cycles:

Back 56

1) changes in eccentricity – revolution about sun
2) changes in obliquity – rotational axis
3) precession – rotational axis

Front 57

What are the major greenhouse gases?

Back 57

H2O, CO2, CH4, NO2, O3

OXYGEN (O2) IS NOT ONE

Front 58

What are the probable anthropogenic (human) impacts on global warming?

Back 58

Sea level rise, climate (drier vs wetter), warmer

Front 59

Two factors that determine where deserts are formed

Back 59

1) worldwide wind circulation patterns- create regions with low precipitation, subtropical high pressure zones

2) topographic effects – “rain shadow”- precipitation falls on one COASTAL side of mountain range, opposite (AWAY FROM OCEAN-LANDWARD) side is arid

Front 60

What transport agent (ice, wind, or water) does most of the basic work of erosion, transportation, and deposition in deserts?

Back 60

Water

Front 61

What is desert pavement?

Back 61

Formed by DEFLATION

surface layer is primarily formed of larger-sized (bigger than sand) particles by wind

Front 62

Ventifacts

Back 62

Formed by abrasion

Front 63

Loess Deposit

Back 63

Dust Sized Particles

Front 64

Dunes
Barchans

Back 64

Solitary, crescent shaped, tips point downwind, limited sand supply, little vegetation, constant wind direction

Long, wavy ridges that lie transverse perpendicular to wind, lots of sand, moderate velocity winds
3) Longitudinal-
Long, straight ridges, parallel with wind direction, formed by steady, high velocity winds, limited sand supply
4) Star-
Mound of sand having high central point with three or four ridges radiating outward from center, occurs in regions with winds coming from many directions
5) Parabolic-
Look like barchan dunes in reverse, tips point upwind, common in costal areas, vegetation anchors tips, center is eroded

Front 65

Dunes
Transverse

Back 65

Long, wavy ridges that lie transverse perpendicular to wind, lots of sand, moderate velocity winds

Front 66

Dunes
Longitudinal

Back 66

Long, straight ridges, parallel with wind direction, formed by steady, high velocity winds, limited sand supply

Front 67

Dunes
Star

Back 67

Mound of sand having high central point with three or four ridges radiating outward from center, occurs in regions with winds coming from many directions

Front 68

Dunes
Parabolic

Back 68

Look like barchan dunes in reverse, tips point upwind, common in coastal areas, vegetation anchors tips, center is eroded

Front 69

What are the fundamental characteristics of a wave?

Back 69

1) Wave height- displacement between peak and trough of wave
2) Wave length- distance travelled during one cycle of wave
3) Wave period- time that it takes to complete one cycle of wave

Front 70

How does wind speed impact ocean waves?

Back 70

higher wind speed, greater wave height

Front 71

How does length of time that wind blows impact ocean waves?

Back 71

longer time, greater wavelength, wave period and wave height

Front 72

How does fetch impact ocean waves?

Back 72

(distance of open water over which winds can blow) Greater fetch, greater wavelength, wave period and wave height

Front 73

How do individual particles of water move as a waveform passes by?

Back 73

Move roughly circular

Front 74

What causes waves to break at the shoreline?

Back 74

Wave slows down, wave height increases

Front 75

Sea Arches

Back 75

Hollowed out area formed in headland by wave erosion
Sediment POOR

Front 76

Stacks

Back 76

Formed after collapse of sea arch
Sediment POOR

Front 77

Wave Cut Cliff

Back 77

Nearly horizontal surface extending from beneath wave-cut cliff toward ocean
Sediment POOR

Front 78

Wave Cut Platforms

Back 78

Sediment POOR

Front 79

Beaches

Back 79

Shoreline accumulation of sand
sediment RICH, delaware coast

Front 80

Spits

Back 80

Beach extended from mainland across bay due to longshore drift
sediment RICH, delaware coast

Front 81

Tidal Inlets

Back 81

sediment RICH, delaware coast

Front 82

Baymouth Bars

Back 82

Spit that extends all the way across a bay
sediment RICH, delaware coast

Front 83

Barrier Islands

Back 83

Long, offshore islands of sediment (mostly sand) that trend parallel to mainland shore
sediment RICH, delaware coast

Front 84

Estuaries

Back 84

Semi-enclosed coastal body of water that has free connection with ocean and has water that is less saline than oceans and more saline than freshwater

DELAWARE BAY

Front 85

What type of feature is Delaware Bay?

Back 85

Estuary - river valley, exposed as land recent past

Front 86

What produces the tides?

Back 86

Gravitational attraction
effect of centrifugal forces

Front 87

Spring Tides

Back 87

HIGH TIDES ARE HIGH, LOW TIDES ARE LOWER
occur during NEW MOON and FULL MOON