Global Enviornment Exam Ii

Front 1

Continental Drift Theory

Back 1

- Continents were originally all connected, but broke up and are still drifting apart, so they will continue to change position.
- Super continent = Pangaea
- Break-away masses:
LAURASIA = North America and Eurasia (minus India)
GONDWANALAND = contents of Southern Hemisphere (plus India)

Front 2

How many major and minor lithospheric plates are there?

Back 2

- 7 MAJOR plates
- 8 MINOR plates

Front 3

Tectonic hazards: how are they caused and what types are there?

Back 3

Caused by movement of tectonic/lithospheric plates.
- Earthquakes
- Volcanoes
- Tsunamis

Front 4

Plate tectonics

Back 4

Earth's outermost layer, the lithosphere, is broken into 7 large, rigid pieces called plates (oceanic and continental). These plates are all moving in different directions at different speeds which means they sometimes crash, pull apart, or sideswipe each other. The place where the two plates meet is called a boundary.

Front 5

What processes are involved in plate tectonics?

Back 5

- Diastrophism: breaking and bending of layers of rock (aka. faulting).

- Volcanism: displacement of molten material (extrusive is above the surface and intrusive is below the surface).

Front 6

What are the stages of the gradational process?

Back 6

1) Weathering: disintegration and decomposition of surface rock.
2) Picking up: weathered material is picked up… (erosion)
3) Transportation: weathered material is transported… (erosion)
4) Deposition: weathered material is deposited/laid down.

Front 7

What is mass wasting and what are the different types?

Back 7

Mass wasting: downslope movement of material under the influence of gravity.

1) Fall: rapidly falling pieces of rock downslope; on steep slopes, weathering causes rock fragments to dislodge and fall.

2) Slide: huge rock masses rapidly slide down a slope.

3) Flow: flow of debris downslope that is assisted by its large percentage of water.

4) Creep: very slow movement on debris downslope; fraction of an inch per year.

Front 8

Mercalli scale vs. Richter scale

Back 8

- Mercalli: subjective measure of damage after the fact.
- Richter: numerical scale of the magnitude and intensity of an earthquake.

Front 9

What is base level?
Give examples of permanent and temporary base levels.

Back 9

Base level: lowest point a stream can flow.

- Permanent base level: sea level
- Temporary base levels: waterfall, lake, rapids, where tributary enters master stream, dam with reservoir, etc.

Front 10

What are the agents of the gradational process?

Back 10

- Running water
- Moving snow and ice
- Wind
- Gravity

Front 11

What are the types of stream loads?

Back 11

DISSOLVED LOAD: dissolved debris carried in water.

SUSPENDED LOAD: small particles carried in water that never touch the bottom.

BEDLOAD: larger debris that moves through water by either SALTATION (move by jumping or bouncing along streambed) or TRACTION (move by rolling or sliding along streambed.)

Front 12

What is the wetted perimeter and how do you calculate it?

Back 12

- Area of contact between water and streambed.
- Wetter perimeter = width + depth + depth

Front 13

How much pressure does a cubic yard of water exert?

Back 13

1700 lbs.

Front 14

POROSITY

PERMEABILITY

AQUIFER

INFLUENT vs. EFFLUENT

Back 14

POROSITY: measure of how much of a rock is open space.

PERMEABILITY: measure of how easily a fluid can move through porous rock.

AQUIFER: subsurface rock layer that can contain water.

INFLUENT: stream provides water to aquifer.

EFFLUENT: aquifer provides water to stream.

Front 15

How much water does the Amazon discharge?

Back 15

6 million cubic ft/sec

Approx. 20% of all the water discharged by all the streams in the world.

Front 16

What factors determine the VOLUME and VELOCITY of a stream?

Back 16

VOLUME
- Size of watershed
- Climate

VELOCITY
- Gradient (slope)
- Volume
- Friction (wetted perimeter)

Front 17

What two processes may produce a valley?

Back 17

1) Stream action

2) Diastrophism (tectonic activity)

Front 18

ERRATIC

BOULDER TRAIN

OUTWASH PLAIN

PITTED OUTWASH PLAIN

Back 18

ERRATIC: boulder that was transported a long distance from its origin (through plucking).

BOULDER TRAIN: group of erratics.

OUTWASH PLAIN: big, broad area created when multiple melt-water streams from the glacier deposit sediment.

PITTED OUTWASH PLAIN: outwash plain with kettle holes.

Front 19

DRUMLIN

CIRQUE

ARETE

HORN

Back 19

DRUMLIN: pile of till resembling an upside-spoon, with the handle pointing in the direction that the glacier is advancing.

CIRQUE: bowl-shaped depressions at the head of the glacial valley.

ARETE: serrated ridge between two cirques.

HORN: peak that forms when multiple cirques erode a mountain

Front 20

ABLATION

TILL

KETTLE HOLE

Back 20

ABLATION: consolidation of snow into hard glacier ice.

TILL: deposited debris from glacier.


KETTLE HOLE: crater in a till formed when a chunk of ice from the retreating glacier embeds in the till and then melts; when it is filled with water it is called kettle lake.

Front 21

Types of glacial erosion?

Back 21

1) Abrasion: process where debris in glacier scrapes against an underlying rock and the resulting debris is incorporated into the glacial ice by partial melting and refreezing.

2) Plucking: process where melting and refreezing of the glacier loosens hunks of rock along the way and then incorporates them into the glacier as it continues to melt and refreeze.

Front 22

What are the different types of moraines?

Back 22

1) Terminal: pile of till dumped at farthest advance of glacier.

2) Recessional: pile of till dumped during a halt in retreating glacier.

3) Lateral: pile of till formed on sides of glacier as it retreats.

4) Medial: structure formed from two lateral moraines merging together.

5) Ground: till-covered areas often forming gently rolling hills or plains, located between lateral moraines. Sometimes retreating ice can carve them into drumlins.

Front 23

What are examples of erosional and depositional features of a glacier?

Back 23

EROSIONAL
- Cirque
- Arete
- Horn

DEPOSITIONAL
- Moraine
- Erratic
- Outwash plain
- Drumlin

Front 24

Types of sea ice?

Back 24

1) Pack ice: giant mass of floating ice.

2) Ice floe: large, flattish mass of ice that breaks off from larger mass and floats independently.

3) Shelf ice: giant chunk of a continental ice sheet that projects out over the sea.

4) Iceberg: chunk of floating ice that breaks off from an ice shelf or glacier.

Front 25

SEAFLOOR SPREADING

SUBDUCTION

Back 25

SEAFLOOR SPREADING: oceanic ridges are formed by currents of magma rising up from the mantle (often during volcanic eruptions) creating new crust on the ridges; associated with divergent boundaries.

SUBDUCTION: trenches are formed by older crust descending into the interior of the earth, where it is melted and recycled; associated with convergent boundaries.

Front 26

Types of plate boundaries?

Back 26

1) TRANSFORM BOUNDARY: two plates side-swipe each other.

2) DIVERGENT BOUNDARY: two plates move apart from each other.

3) CONVERGENT BOUNDARY: two plates collide.

Front 27

Types of convergent boundaries?

Back 27

1) OCEANIC-OCEANIC: creates oceanic trench and volcanoes on ocean floor.

2) CONTINENTAL-CONTINENTAL: no subduction occurs, so mountain ranges are built up; earthquakes common, but volcanoes are rare.

3) OCEANIC-CONTINENTAL: oceanic plate subducted under continental plate; creating oceanic trench and coastal mountains.

Front 28

VALLEY vs. INTERFLUVE

Back 28

VALLEY: portion of land in which drainage system is clearly established.

INTERFLUVE: the higher land or ridge above the valley sides that separates adjacent valleys; also, no clear-cut drainage system.

Front 29

What are the stages of the Geomorphic cycle?

Back 29

YOUTHFUL STAGE
- Streams become established
- V-shaped valleys and steep gradient.
- Rapids and waterfalls
- Undeveloped drainage system
- Few tributaries

MATURE STAGE
- Transitional stage
- U-shaped valleys
- Number of tributaries increases
- Lateral erosion

OLD AGE STAGE
- Velocity decrease
- Meandering
- Aggradation
- Back swamps

Front 30

COMPETENCE vs. CAPACITY

Back 30

COMPETENCE: largest boulder a stream can carry.

CAPACITY: maximum load a stream can transport at a given time.

Front 31

PERENNIAL STREAM

INTERMITTENT STREAM

EPHEMERAL STREAM

EXOTIC STREAM (example?)

Back 31

PERENNIAL STREAM: flows year-round.

INTERMITTENT STREAM: flows for only certain parts of the year.

EPHEMERAL STREAM: flows only during wet season or during or immediately after it rains.

EXOTIC STREAM: type of perennial stream that starts in a humid region and flows through an arid region. (ex. Nile)

Front 32

DELTA

TRIBUTARY

DISTRIBUTARY

Back 32

DELTA: area at mouth of stream where debris is deposited.

TRIBUTARY: brings water to the stream; also, you recognize the right or left side by looking downstream.

DISTRIBUTARY: branching stream channel that crosses a delta and through which water flows to ocean.

Front 33

GRADED STREAM

KNICK POINT

THALWEG

Back 33

GRADED STREAM: carrying all that it is capable of carrying.

KNICK POINT: sharp irregularity in profile of stream (ex. waterfall)

THALWEG: deepest/most often used channel in the river.

Front 34

What area of the earth's surface is covered by glacial ice?

Area included in periglacial region?

Back 34

GLACIAL ICE = 11%

PERIGLACIAL = 1/3 +

Front 35

MONADNOCK

NUNATAK

MOULIN

Back 35

MONADNOCK: remnant of elevated surface that stream has not been able to erode (ex. mesa)

NUNATAK: elevated land form that rises above the back of a glacier.

MOULIN: drainage hole in the ice (ex. fracture).