Geography 104 exam #3 (UWEC, Jol)

Earth's four spheres

atmosphere, hydrosphere, lithosphere, biosphere

relief

Elevation of local landscapes highest, lowest, average

Topigraphy

Character and configuration of earths surface

Geomorphology

Subdivision of Earth Science that studies how the landforms on the planet's surface are created

geologic time scale

Relative or absolute time

Superposition

a principle that states that younger rocks lie above older rocks if the layers have not been disturbed

Uniformitarianism

A principle that geologic processes that occurred in the past can be explained by current geologic processes

Cycle of Gradation

1) Erosion (degradation)

2) Transportation (gravity, wind, water, ice)

3) Deposit (aggradation)

fluvial

River or stream

Alluvium

sediment deposited by streams (gravel, clay, sand, silt)

runoff equation

M precipitation- evaporation +\- change in storage in m^3/s flowing past a point

drainage basin

basic spatial geomorphic unit of a river system

continental drift

the theory that the continents were once joined and then slowly drifted apart

streamflow equation

Q=(width)(depth)(velocity)

stream gages

measures height of water flowing

Flood hydrograph

graph of stream discharge over a time period for a specific place, lag time, peak, rising limb, falling limb, base flow

flood abatement measures

detain and delay runoff, modify the lower reaches

Slope/Gradient

the amount of change in elevation per horizontal distance

Long profile

change in slope from stream source to outlets (Stream channel component)

Knick point

when long profile has abrupt change in slope (Stream channel component)

base level

- level below which stream cannot erode

Types of erosion

hydraulic action, bank caving, abrasion/attrition, solution (corrosion)

Types of stream transportation

solution, suspended load, bed load

Deposition

decrease in flow, deposition decreases, deltas (into water), alluvial fans

meandering stream

single channel, suspended sediment, point bar, cut bank

braided stream

coarser sediment, bedload dominated, fluctuating discharge, steeper slope

Channel/Alluvial Terraces

- Level areas that appear as topographic steps above a stream

- Created by the stream as it scours with renewed downcutting into its flood plain

entrenched meanders

incised river meanders excavated deeply into the landscape, rejuvenation

Floodplain Landforms

a flat low-lying area along a river, created and subject to recurrent flooding, levee formation

Classification of glaciers

Slowly moving mass of dense ice, year round ice

snow line

the lowest elevation on mountains where snow remains year-round

Two categories of glaciers

Alpine (ice cap/field)

Continental (ice sheet)

Glacier Dynamics (how it's formed)

Conversion of snow to ice - loose snow - firn - glacial ice

Glacial Mass Balance

Zone of accumulation

Zone of ablation

Equilibrium Line

Glacier Movement: Internal

Crevasses, glacial surge

Glacial Erosion

plucking and abrasion

glacial erosional features

U-shaped valley, glacial trough, Striae, glacial polish, glacial flour/rock flour, cirque, arete, horn, col, hanging valley, tarn, paternoster lakes, fjord, roche moutonnee, drumlins

Glacial Deposition

Glacial debris/deposits- Supra, en, sub- glacial

till, moraine

contact with ice when deposited usually unsorted

Moraines

Lateral, medial, terminal, recessional, ground

drift

deposited directly or indirectly by glacier

ice-contact deposits

Moraines/till/erratic

glaciofluvial deposits

Meltwater with ice when deposited

Usually sorted

Wide range of deposits

Wide range of sediment sizes

Outwash plain, drumlins, eskers, kettle holes

Antartica

Each year approximately doubles in size max in October/ min in February

Quanternary glaciation

Cycles of glaciation/deglaciation

Multiple glaciation during last 2.58 m yrs

Interrupted by warmer periods- interglacials

glacial stages

- Wisconsinan (glacial)

- Sangamonian (interglacial)

- Pre-Illinoian

Effects of Glaciation

Changed much of the landscape

Lowering sea levels and temperatures

Much more info from ice cores

Coastal background

50% of NA population lives on coast

9$ trillion of coastline insurance

Great Lakes are 90% of us freshwater

ocean currents

Driven by prevailing wind patterns on earths surface

Long shore currents

Tides

Rise and fall of ocean levels as a result of the gravitational attraction of the moon on the earth

Types of tides

Neap tides, spring tides

Current names

Ebb current (seaward), flood current (landward)

Waves

Water motion- loop shaped pattern, loops decrease with increasing depth

Waves formation

Wind direction, strength, fetch

wave swash

Landward

Wave backwash

Seaward

Constructive waves

Swash > backwash

Destructive waves

Backwash > swash

littoral zone

Contact between land and water

-mean sea level

littoral drift

=beach drift + long shore drift

Types of beaches

Progradation, retrogradation

Progadation (beach)

More sand arrives than removed

Retrogradation (beach)

More sand removed than arrives

wave refraction

- distribution of wave energy along shore

- leads to converging at headlands

- leads to diverging in bays

Rising sea levels and global warming

Threat is real

Change in water volume of world ocean

Evidence to support continental drift

coastline fit, geological fit, paleoclimatology, paleoglaciation, fossil correlation, paleomagnetism

Theory of Plate Tectonics

general theory of lithospheric plates with their relative motions and boundary interactions

plate boundaries

divergent (spreading) , convergent, transform (transcurrent)

folds in the earths crust

monocline (one fold), anticline (High), syncline (low)

fault

Is a plane or rock fracture along which there is motion of the rock mass on one side with respect to other side

Types of faults

normal (tension) , reverse (compression), strike-slip or transcurrent (lateral shearing), graben (tension), Horst (compression)

earthquake

Motion of the earths surface

Richtor Scale

the scale used to measure the intensity of earthquakes ; assigns a single number to quantify the amount of seismic energy released by an earthquake. (Logarithm)

Seismograph

Records vertical and horizontal motion of earth and magnitude of motion

Liquefaction

The process by which an earthquake's violent movement suddenly turns loose soil into liquid mud

Tsunami

A giant wave usually caused by an earthquake beneath the ocean floor.

Places to see now

Patagonia, South America. (Melting glaciers) Mekong delta, Vietnam (salt water intrusion)

Great Barrier Reef (changing ocean)

Maldives (sea level rise)

Knick point

a step or drop in a river's bed which often cause waterfalls