geology exam 1

geoscience

study of modern earth and earths processes and its future, by studying it today and its past

4.6 billion

earth is ________________ years old

earth systems science

ESS

ESS

science that studies all earth as a system of innumerable interacting parts and focuses on changes within and among those parts

oxygen

makes up 20% of the atmosphere

overpopulation

#1 earthly issue

system

assemblage of things connecting, associated, or interdependent, to form a complex unity; a whole composed of parts in orderly arrangement according to some scheme or plan

systems concept

way to break down something large to create a complex unity

6

earth system has how many spheres?

atmosphere

gas budget of earth

hydrosphere

water budget of earth

cryosphere

ice budget of earth

geosphere/lithosphere

solid earth-rock and regolith

biosphere

earth's lifeforms

anthroposphere

human activity

loess

sediment that is formed by the accumulation of wind-blow dust (makes up 10% of earth's land area)

earth

_______ is an open system on a large scale but acts essentially as a closed system on geological short time frame (human time)

fixed and finite

matter is

principle of environmental unity

components/spheres of earth's inter-linked w/ each other; what happens in one sphere will inevitably affect other spheres

feedback (+,-)

everything affects everything else b/c of connectedness and __________

le chateliers principle

any system in equilibrium that is perturbed will react to 1. return to the original equilibrium 2. establish a new equilibrium

perturbation

temporary disturbance ex. climate cooled over several years

forcing

persistent disturbance ex. global warming (150 yrs.)

temporal scales

earth processes occur on ______________ranging from milliseconds to billions (Ga) of years

spatial scales

earth processes occur on _____________ (size) ranging from fractions of mm to thousands of km

temporal

ex. speed of lightening to slow erosion that carves grand canyon

spatial

ex. atoms in mineral to diameter of sun (San Andreas fault)

feedback

condition where output of system is also input (causes change) to same system

positive feedback

outcome of one event's changes amplifies next event (vicious cycle)

negative feedback

outcome of one event decreases process for next event, eventually approaching "steady state" (never fully reached)

positive feedback

ex. hurricane formation

negative feedback

ex. clouds formation

equilibrium state

system will not change unless disturbed

stable equilibrium

system will return to equilibrium state if disturbed slightly

unstable equilibrium

small disturbance will carry system away from equilibrium state to reach new equilibrium state

tipping points; threshold effects

systems resist change until overwhemled, followed by sudden change

magnitude-frequency relationship

inverse relationship b/n frequency of an event and magnitude of an event

deductive approach

run experiments using chemistry, physics, biology, math
to confirm some observations

inductive approach

study patterns through 4.6 billion years of earth’s history
to explain other observations

experimental sciences

independent of time of occurrence

historical sciences

time plays a critical role in process

compelling

generally only 1 good explanation for data and observations (best)

presumptive

only 1 or 2 viable explanations for data as long as initial assumptions (givens) hold

permissive

several viable explanations with some evidence supporting each model (many assumptions must be made)

suggestive

evidence is consistent with hypothesis; however, the evidence doesn't prove or disprove the hypothesis (worst)

parsimonious

simplest explanation best

consilient

explains wide range phenomena

observation

what we can quantify or qualify based on our observations (who,
what, when, where)

interpretation

explanation of the cause or meaning of our observations (why,
how, so what)

observations and interpretations

_______ may be correct, but the __________ may be incorrect or incomplete

scientific study

starts with premise that natural laws are consistent and predictable

falsifiability

statement (hypothesis) has the inherent ability to be proven false, or refuted

scientific theory

well-tested, but not as yet falsified, so widely accepted
understanding that scientific community agrees best explains observable facts

scientific law

statement of fact, generally accepted as universal, & always
observed as being true

heuristic

learn about it by experiencing it

holistic

all encompassing

hermeneutic

mostly interpretive rather than descriptive

"deep time" perspective

geological time scale beyond human time scope

atmosphere

- gas envelope surrounding earth
- held to earth by gravity
- extending 100s of km upward
- origin: volcanic outgassing
- creates hydrosphere

weather

day-to-day atmospheric aspects of T, ppt, wind, cloudiness, pressure, etc. (result of climate)

climate

regionally average prevailing weather conditions over series of years

weather

e.g. maximum variations occur on annual cycle

weather

e.g. generally controlled by short-term changes in atmosphere T and moisture

weather

e.g. can be locally controlled by geographic features such as mountains and lakes

climate

e.g. variations occur on longer cycles (decades to tens of thousands of years)

climate

e.g. controlled by long-term changes in atmosphere, hydrosphere, cryosphere, geosphere, and biosphere

stable gases

percent remains fairly constant over time; what leaves gets replaced; has little effect on weather

variable gases

percent changes; make up a small percent but have greater impact on weather and climate

H2O vapor (0%-4%)

gaseous state of water
- most abundant over tropical oceans, least in deserts and poles
- source for all clouds and ppt
- highly efficient at absorbing outgoing radiation (greenhouse effect)

carbon dioxide (CO2: 0.0411%)

- absorbs outgoing terrestrial radiation (greenhouse effect)
- up-taken in by plants (photosynthesis) and absorbed by oceans
- variable b/c increasing over last century
- widespread burning of fossil fuels, vegetation, etc.

ozone (O3)

0.0002% (2 ppm)
- forms through reaction b/n O2 and incoming radiation
- upper atmosphere - it protects us from harmful uv radiation
- at earth's surface - high concentration considered pollution b/c it irritates lungs

particulates

airborne solid and liquid particles soil, sand, pollen, fire, ash, etc,

volcanic ash

microscopic si glass
- many absorb water and "nucleate" ppt

temperature and density

drives atmospheric processes (especially air circulation)

temperature

average molecular motion of a body; measure of heat content (heat is a source of molecular motion

atmospheric pressure

weight of atmosphere above a point

density

amount of something in a given space

mass/volume

density= (e.g. H2O= 0.997g/cm3)

density and pressure

decrease w/ increasing height

T

decreases overall w/ increasing height (esp. above 2 km altitude)

T

subject to increasing w/ increasing height (inversion)

exosphere
thermosphere
mesosphere
stratosphere
troposphere

order of atmospere's layers based on T

troposphere

all weather takes place in

troposphere

99% of atmospheric mass

troposphere

height b/n 6-12 miles

troposphere

highest at equator, lowest at poles; varies seasonal

stratosphere

most important for us=ozone (O3) layer

stratosphere

9-22 miles above earth's surface

stratosphere

T increases with altitude in

mesosphere

meteorites burn up upon entry

mesosphere

rare noctilucent (night-shining) clouds and electrical discharges (e.g. sprites; "flutters")

mesosphere

T decrease w/ increase altitude

thermosphere

T increases w/ higher altitude (solar radiation)

auroras

charged ions from space interact w/ molecules in thermosphere (northern and southern lights)

karman line

space begins (62 miles/100km)

exosphere

extend above thermosphere until all molecules bound by earth's gravity taper off into space

exosphere

most satelites orbit here

dipolar molecule

positive end of H2O molecule bonds to negative end of another

triple point of state

occurs at earth's surface

dynamic processes

any process that changes over time (evolves) e.g. earthquakes, precipitation, landslides, photosynthesis