APES REVIEW:EARTH SYSTEMS

AND GLOBAL CHANGES

Miss Hayungs

PROPERTIES THAT DRIVE GLOBAL PROCESSES 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.

T P D As temperature increases, pressure

increases As temperature decreases, pressure

decreases As pressure increases, density decreases As pressure decreases, density increases

T P DT P D

The key is to remember how the molecules move in relation to the temperature and what that means for density

CONVECTION 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 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.

CONDUCTION 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.

RADIATION 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)

PROPERTIES OF WATER 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)

LITHOSPHERE – PLATE TECTONICS 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 SpreadingHarry 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)

PLATE TECTONICS 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 boundariesConvergent boundariesTransform boundaries

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

TransformPlates slide past each other.No new crust formed, no recycling of crust

Ex. San Andreas fault

Transform boundary

EARTHQUAKES 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…

SEISMIC WAVES Primary waves (P-waves)

CompressionMove through any material and arrive at

seism,ic station first Secondary waves (S-waves)

Lateral motionSlower than p-waves and only move

through solids Surface waves (L-waves)

Only sensed at surface

EARTHQUAKES Three seismic stations are needed to

triangulate where the focus occurred

The Richter ScaleLogarithmic 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!)

ROCK CYCLE The cycling of rock between three types of

material: Igneous rock – formed from cooling of magma

Intrusive/extrusive classification based on where it forms

Felsic/intermediate/mafic/ultramafic classification based on mineral composition of rock

Sedimentary rock – formed from weathering, erosion, deposition, burial, lithification 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)

IGNEOUS ROCK

SOIL 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

SOIL HORIZONS WITHIN A PROFILE

R horizon

Topsoil

Subsoil

Zone of eluviation and leaching

SOIL CONSERVATION Agricultural methods

No-till farming or low-till farmingTerracing or contour farmingTrees as wind breaks

Case Studies1930s Dust Bowl in the plains states

1935 Soil Conservation Act

HYDROSPHERE – THE OCEAN 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)

OCEAN 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

ATMOSPHERE 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.

COMPOSITION OF THE ATMOSPHERE 78% Nitrogen 21% Oxygen 0-4% H2O(g)

The other 1% is all other elements (Ex.: Ar, CO2, Ne, He, CH4, H2, O3, etc.)

LAYERS OF THE ATMOSPHERE 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 mi – stratosphere 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 – mesosphere Contains some ice-crystal clouds; temperature

decreases with height in this layer; this is the coldest layer of atmosphere. Mesopause comes next

LAYERS OF THE ATMOSPHERE 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.

WEATHER 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

easterliesThese winds also help to distribute solar

heat around the globe. Hadley, Ferrell, and Polar cells

CLOUDS 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)

CLOUD NAMES Clouds are named by their appearance

and altitudeCumulus 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 cloudLow-level do not necessarily have a prefix

Ex. Altocumulus clouds are mid-level clouds that look puffy and billowy

WEATHER FRONTS 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

ASSOCIATED WEATHER 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.)

SEVERE WEATHER 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)

CLIMATE 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.

MILANKOVITCH CYCLES

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

OTHER NATURAL EVENTS Sunspot cycles

A 22-year cycle of min & max # of sunspots Volcanic eruptions

Cause general cooling of Earth due to particulates blocking sun’s rays

El 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

EFFECTS OF CLIMATE CHANGE 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 disease-carrying 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

SEASONSResult 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

hemisphereThis exposure alternates as the Earth

revolves in its orbit. N and S hemispheres experience opposite

seasons.

CASE STUDIES Yellowstone Hotspot Coastal Vulnerability to Rising Sea

Levels Coastal Vulnerability to Hurricanes El Nino and Landslides

CITATIONSMiller, 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.

Created using MLA Citation Maker on www.oslis.org.