geo exam 4

hydrologic cycle

driven by solar energy and gravity

réservoirs and passages

significance of streams

affects:

- landscape development

- environment

- water supply transportation, recreation

- erosion, flood, pollution, river boat gambling

stream

- body of flowing surface, usually confined in a channel

stream profile

(plotting elevation) Longitudinal = concave upward

x-sectional = V-shaped valley in bedrocks => channel in sediment

drainage basin

entire area drained by stream and its tributes

drainage divide

a ridge of high ground dividing drainage basins

factors affecting stream behavior

velocity(speed and direction of flow)

channel shape

wide and shallow=slow

skinny and deep=fast

circle back

circle

stream erosion

actions:

-dissolution

- hydraulic action

- abrasion

development of a longitudinal profile

balance amount erosion, transportation and deposition

steep upstream

erosion near headwater

gentle downstream

deposition near base level

V-shaped valley (valley = channel)

down-cutting of stream (slot canyon)

- mass wasting of the wall

glacial deposits(till)

unsorted mixture of sediments, no bedding,

erratic

ice transported boulder

outwash

deposited by melt water

moraines

basically a rock moat

drumlins

teardrop shaped hill

streamlined hills of till

- pointy ends point in direction of ice flow

outwash

deposited by melt water

- sorted sediments with bedding structures

- little chemical weathering

esker

winding ridge of stratified deposits

kettle lake

lake formed by stagnant ice blocks left behind by retreating glaciers

kame

lake sediment. originally on ice surface

depositional

bars:

- point bars(along the banks)

- mid channel bars(variable discharge and erosion of banks)

flood plains:

- floor of the alluvial valley

- flood deposits

excess discharge(in flood plains)= over flows channel

reduction of flow speed(in flood plains)

deposition

natural levees

- coarse-grained sediments heavy

- heavy material drops out of suspension first as velocity slows on flat floodplain

terrace

- step-like landform above current stream channel and flood plain

- down-cutting of a previous flood plain

aluvial fans

reduction of gradient

- talus slopes

deltas

bodies of water(similar to small river) that flows into a bigger body of water such as a lake or an ocean

- no erosion

- distributory channels

drainage patterns: dendritic

pattern=root like

control= homogenous bed rocks

trellis(drainage patterns)

pattern= parallel main and short tributaries

control= differential weathering

rectangular(drainage patterns)

pattern=grids

control= patterns of fracture

radial

pattern: circular-aligned

composite and dome volcanoes

glaciers

- large mass of snow and recrystallized ice

- persists year-round

move dye to gravity

type of glaciers

alpine and continental

glacial budget

balance of gains(snowfall) + losses(melting +breaking off pieces/icebergs)

positive budget

volume of ice increasing

- glacier, "advancing" and spreading over new land,

- alpine glaciers advance to lower elevations

- continental glaciers advance to lower latitudes

negative budget

volume of ice decreasing

- glacier, "retreating," alpine glaciers retreat to high elevations and continental glaciers retreat to higher latitudes

glacial deposits(till)

unsorted mixture of sediments

- no bedding

erratic

- ice transported boulder

- sizes vary

outwash

deposited by melt water