Transcript APES Review: Earth Systems and Global Changes

Miss Hayungs
 Remember
some key scientific concepts:
 The
relationship between Temperature,
Pressure, and Density (relates to convection)
 Convection,
Conduction, and Radiation
(transfer of heat or heat energy)

These are all factors in remembering movement
in the atmosphere, oceans, mantle, etc.
 As
temperature increases, pressure increases
 As temperature decreases, pressure decreases
 As pressure increases, density decreases
 As pressure decreases, density increases


T
T
 The
P
P
D
D
key is to remember how the molecules
move in relation to the temperature and what
that means for density
 Energy
is moved by energy-containing
particles from one place to another (primary
in the atmosphere, oceans, and within Earth)
 This is the circulation of material that occurs
when the density of material is decreased
due to warming or increased due to cooling.
The movement of matter here forms a
convection current due to the rising of less
dense matter and sinking of the cooler
matter.
 Convection
in the mantle is the mechanism for
plate movements.
 Convection in the atmosphere is responsible for
global winds (think back to Hadley, Ferrel and Polar
cells), formation of some clouds, high and low
pressure systems, and ultimately for various
climates and biomes.
 Convection in the oceans helps to move cold
and warm water currents around the globe and
adds to pressure differences. (thermohaline
circulation involves differences in temp and salinity)

Convection moves heat that comes from the sun
and distributes it around the globe.
 Energy
transferred from one particle to
another through a collision between the two
particles.
 When this happens some heat is produced.

Example: The molecules in the pot of water
heat up because the pot is touching the burner.
 Energy
carried by a photon from one place to
another
 Radiation is energy that comes from a source
and travels through some material or through
space. Light, heat and sound are types of
radiation.


Ionizing radiation can produce ions in matter.
(Ex…the more damaging end of the EM spectrum)
 Weather
is affected by convection,
conduction and radiation, but also properties
of water such as:
 Specific heat (moderation of temperature
fluctuations along coastal areas or near large
bodies of water)
 Energy of vaporization (evaporative cooling)
(latent heat) (Ex. Evaporation of water –
holds or stores a lot of energy for use in
hurricane)
 Theory


of Continental Drift
Alfred Wegener proposed that all of the
continents were once joined together (matching
coastlines, fossil correlations)
This was rejected by the scientific community
because he had no explanation for how/why the
continents moved.
 Seafloor

Spreading
Harry Hess compiled data from several scientists
to explain his theory of seafloor spreading.
(sonar used to map the topography, magnetic
readings of rock, sediment data, isochron maps
of seafloor)
 Using
all of the data compiled over the
decades from several scientists, the Theory
of Plate Tectonics was developed.
 Types of crust

Continental and Oceanic
 Plate



Boundaries -
Divergent boundaries
Convergent boundaries
Transform boundaries
 Divergent



Plates move away from each other
Oceanic-Oceanic divergence= new crust formed
at oceanic ridge
Continental-Continental= new crust formed at
rift valleys

Ex- Mid-Atlantic Ridge and African Rift
 Convergent


Plates move toward each other; oceanic plate
will subduct
Continental-Continental convergence= no
subduction; plates will buckle – forms tall, folded
mountains

Ex. Himalayas
Divergent boundary of
oceanic crust
Convergent boundary
of oceanic and
continental crust

Oceanic-Oceanic=one plate subducts, forming a
trench; the subducted plate will be
melted/recycled; volcanic islands are formed


Ex. Mariana trench and Japan
Oceanic-Continental=oceanic plate subducts,
forming a trench at the subduction zone;
volcanic mountain range forms on continent

Peru-Chile trench and Andes Mountains
 Transform


Plates slide past each other.
No new crust formed, no recycling of crust

Ex. San Andreas fault
Transform
boundary
 Plate
boundaries are seismically active and
prone to earthquakes.
 When the plates move, there is friction
between the plates, eventually the plates
will “give”, and there is a release of kinetic
energy.
 Where the rocks “give” is the focus.
 Directly above the focus at the surface is the
epicenter.
 Seismic waves radiate outward from the
focus – three types…
 Primary


waves (P-waves)
Compression
Move through any material and arrive at seism,ic
station first
 Secondary


Lateral motion
Slower than p-waves and only move through
solids
 Surface

waves (S-waves)
waves (L-waves)
Only sensed at surface
 Three
seismic stations are needed to
triangulate where the focus occurred
 The


Richter Scale
Logarithmic scale that measures the intensity of
the earthquake.
For every increase in whole number on the
Richter scale, there is a ten-fold increase in
ground displacement and 30-fold increase in
energy released.

(Ex. 1960 Chile earthquake measured a 9.5!)
 The
cycling of rock between three types of
material:

Igneous rock – formed from cooling of magma



Sedimentary rock – formed from weathering, erosion,
deposition, burial, lithification



Intrusive/extrusive classification based on where it forms
Felsic/intermediate/mafic/ultramafic classification based on
mineral composition of rock
Clastic/organic/chemical classification based on how it forms
Clastic sedimentary rock is further classified by grain size
Metamorphic rock – formed by exposure to heat and
pressure

Foliated/non-foliated classification based on presence of lines
or lack of lines seen in rock (texture)
 Soil
forms from the weathering of rock. It
can take hundreds to thousands of years to
create a deep soil.
 Soil composition depends on the minerals in
the parent rock. Nutrients come from these
minerals and the organic material that will
decompose and become part of the nutrient
load.
 Soil profiles (cross-section of horizons)

Will vary by biome due to amount and type of
weathering as well as amount of precipitation
Topsoil
Zone of
eluviation and
leaching
Subsoil
R horizon
 Agricultural



No-till farming or low-till farming
Terracing or contour farming
Trees as wind breaks
 Case

methods
Studies
1930s Dust Bowl in the plains states

1935 Soil Conservation Act
 Ocean
currents

Help to disperse heat from the sun around the
globe

Ocean currents caused by:


Wind (surface currents)
Differences in salinity and temperature (density
currents or deep water currents)
 Tides

Caused by the gravitational pull of the sun and
moon

Remember the tidal range and the adaptations of
the organisms in the intertidal zone
 Origin
– remember the Miller and Urey
experiment
 Evolution
- Primitive Earth’s atmosphere was
very different in the first few hundred
million years (probably hydrogen and helium)
and only changed as comets, volcanoes, and
other sources of elements entered the
picture.
 78%
Nitrogen
 21% Oxygen
 0-4% H2O(g)
 The other 1% is all other elements (Ex.: Ar,
CO2, Ne, He, CH4, H2, O3, etc.)
 0-7

mi above surface – troposphere
Most of Earth’s weather happens here; 75% of the
atmosphere’s mass is in this layer; temperature
decreases with height. The tropopause is the
transitional layer between troposphere and stratosphere
 13-30

Most jet travel happens here; the protective ozone layer
causes the temp to increase with height in this layer
(ozone layer aborbs some ionizing radiation) The
stratopause is the transitional layer before the
mesosphere
 31-50

mi – stratosphere
mi – mesosphere
Contains some ice-crystal clouds; temperature decreases
with height in this layer; this is the coldest layer of
atmosphere. Mesopause comes next
 52-300


mi – thermosphere
Includes the Ionosphere
Aurorae; meteors burn up in this layer; temperature
increases with height due to X-rays, gamma rays, and
ultraviolet radiation from the sun
 300-6000

mi – exosphere
This is the transitional layer that leads you to outer
space. The atmosphere slowly decreases in density until
you are into interstellar space. H and He exist in this
layer.
 Temperature,
pressure, moisture, global
wind patterns (and correlating Coriolis
Effect), latitude, natural cycles of the solar
system all come in to play in weather.
 Global winds caused by convection currents.


Tradewinds, prevailing westerlies, and polar
easterlies
These winds also help to distribute solar heat
around the globe.

Hadley, Ferrell, and Polar cells
 Clouds
form when you have warm, moist air
rise and condense

The mechanism that causes the rise may vary


Density difference (cold sinks, warm rises)
 fronts
Mountains (air forced upward over a mountain top is
called orographic lifting)
 Clouds
are named by their appearance and
altitude







Cumulus means “heap”
Stratus means “layer”
Cirrus means “curl of hair” or “whispy”
Nimbus means “rain”
“Cirro-” refers to a high level cloud (made of ice
crystals)
“Alto” refers to a mid-level cloud
Low-level do not necessarily have a prefix

Ex. Altocumulus clouds are mid-level clouds that look
puffy and billowy
 Cold
front – a cold air mass that comes in at
ground-level (cold, dense air)
 Warm front – a warm air mass that moves
into an area (warm air is less dense, so it
“wedges” over the cooler air in front of it)
 Occluded front – Cold air mass overtakes the
warm air mass in front of it, wedging the
warm air upward and between the two
colder air masses
 Stationary front – two fronts moving in
opposing directions meet and neither
advances
 Cold
front – warm moist air lifted quickly
upward, so there can be large, powerful
thunderstorms (some with hail)
 Warm
front – cirrus clouds come in first, then
a steady drizzle can happen. More gradual
weather change than we see with a cold
front
Cold front forcing warm, moist air upward, resulting
in a vertical development cloud (severe t’storm)
Warm front moving into area, gradually lifting
and causing cirrus clouds to form.
Station
Models
Shows the
current weather
for a specific
site (a snapshot
of weather that
can be reported
to news
stations, ex.)
 Hurricane
– cyclonic, low pressure system that is
fueled by the warm ocean waters. It forms off
the coast of Africa and builds in strength as it
moves west in band of trade winds. As it hits
land (N. America) it moves east due to our
prevailing global winds, loses strength and “dies
out” over cooler ocean waters or land. (Saffir
Simpson scale)
 Tornado – cyclonic, low pressure system that is
formed because of the turbulence and wind
shear associated with severe thunderstorms.
(Enhanced Fujita scale)
 Weather
is the short-term variation in
atmospheric conditions.
 Climate
is a long-term variation in the
atmospheric condition (an accumulation of at
least 30 years’ worth of data)
 There
are natural and anthropogenic causes
to the changes in Earth’s changing climate.

The collective effect of changes in Earth’s
movements upon its climate

Earth's perihelion and aphelion
-Earth is closest to the Sun (perihelion) in
early January and farthest (aphelion) in early
July.
-The relation between perihelion, aphelion
and the Earth's seasons changes over a
21,000 year cycle.

Axial tilt, precession and eccentricity of
Earth's orbit vary in several patterns,
resulting in 100,000-year ice age cycles over
the last few million years.

The Earth's axis completes one full cycle of
precession approximately every 26,000
years.
-Precession refers
to the movement
of the rotational
axis of a body (like
a spinning top as it
wobbles)

The eccentricity of Earth’s orbit is currently
about 0.0167. (how far from circular the orbit is)
 Over
thousands of years, the eccentricity of the
Earth's orbit varies from nearly 0.0034 to almost
0.058 as a result of gravitational attractions between
the planets.
The elliptical orbit rotates, more slowly, leading
to a 21,000-year cycle between the seasons and
the orbit.
 The angle between Earth's rotational axis and
the normal to the plane of its orbit moves from
22.1 degrees to 24.5 degrees and back again on
a 41,000-year cycle.

 Currently,
this angle is 23.44 degrees and is
decreasing.
Milankovitch Variations
 Sunspot

A 22-year cycle of min & max # of sunspots
 Volcanic

eruptions
Cause general cooling of Earth due to
particulates blocking sun’s rays
 El

cycles
Nino Southern Oscillation (ENSO)
Also in a cycle that affects coastal AND inland
regions; can greatly change that year’s
precip/temp/storm amounts
 Greenhouse


Effect (Enhanced)
Greenhouse effect makes conditions conducive to
life on Earth (amt of greenhouse gases)
Too much of a “good thing” causes increased
heating





Reduction in sea ice and
change in albedo
Decrease in seasonal ice melt
to local watersheds
Higher ocean levels that may
flood coastal population
centers
Spread the range of diseasecarrying vectors that are
indigenous to warmer
climates
Extinction rates will increase
when the natural evolution
and co-evolution (re:
adaptations) cannot keep up
with a shift in biotic/abiotic
factors



Biodiversity of coral reefs will
decrease as ocean temps
increase, causing bleaching
Methane hydrate released
into atmosphere from melting
permafrost (greenhouse gas)
as well as damage to
structures already in place in
those regions
Warmer oceans will allow for
increased rates of
evaporation, giving more
energy to storms (increased
storm intensity or more
incidences)
Seasons
Result from Earth’s axis being tilted to its
orbital plane at an angle of approx. 23.5
degrees and Earth’s position in its orbit.
 At any given time during summer or winter,
one part of the planet is more directly
exposed to the rays of the Sun (more direct
sun rays = summer)

 Aphelion
in summer/perihelion in winter for N
hemisphere

This exposure alternates as the Earth
revolves in its orbit.
N
and S hemispheres experience opposite
seasons.
 Yellowstone
Hotspot
 Coastal Vulnerability to Rising Sea Levels
 Coastal Vulnerability to Hurricanes
 El Nino and Landslides
Miller, G T. Living In the Environment. 13th ed.
Pacific Grove, CA: Brooks/Cole, a division of
Thomson Learning, 2004. Print.
Oak Ridge National Laboratory. Web. 20 Apr. 2014.
<http://orise.orau.gov/reacts/guide/define.htm>.
Reel, Kevin R. AP Environmental Science. 2nd ed. USA:
Research and Education Association, 2008. Print.

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