Semester A Review

Earth Science Basics (cycles/branches)

Waves Astronomy

Weather and Oceans

What should you study?

• Old quizzes & Notes • Unit review worksheets/Ticket to Rides • Review WS’s (crossword, fill-in-the-blank) • The 5 concept worksheets from this week.

90 multiple choice and matching

questions Bring pencils and something to do quietly

after the test! Study for other exams!

Branches of Earth Science • Astronomy • Oceanography/hydrology • geology • meteorology

Cycles

Carbon cycle

Waves:Some vocabulary Crest – The uppermost part of a wave Trough – The lowest part of a wave Amplitude – The height of the crest or the depth of the trough -The higher the amplitude the louder the sound (Decibels) Wavelength – The distance between 2 successive crests of waves. Frequency – The number of waves occurring over a period of time. Measured in hertz (Hz). 1 Hz = 1 cycle/ second -High frequency results in higher pitch of sound

2 Basic types of waves

1.) Transverse wave – wave in which the displacement of the medium’s particles is at right-angles to the direction of the wave motion.

2.) Longitudinal wave – wave in which the

displacement of the medium’s particles is in line with or parallel to the direction of the wave motion.

Transverse Wave Longitudinal Wave

Frequency of a sound wave is the number of vibrations that occur in a second. -measured in hertz -The greater the frequency, the higher the note. Pitch is how high or low the sound seems to a person. Intensity is a measure of the amount of energy carried by a sound wave.

imagers.gsfc.nasa.gov/ ems/waves3.html

http://lot.astro.utoronto.ca/images/spectrum.png

The amount of the shift in wavelength is proportional to how fast the thing is moving

: www.bramboroson.com/ astro/feb11.html

Doppler EffectDoppler Shifting - Background Info

• http://www.astrocappella.com/background/doppler_background.shtml

• Blue Shift: As the star moves towards earth, the star appears to have shorter wavelengths (blue = 500nm)

• Red Shift: As a star moving away from earth appears to have longer (red) wavelengths. (approx 650nm)

"Blueshifts come, and redshifts go, and that's pretty much everything you need to know."

This image cannot currently be displayed.

Frequency

• Tuning Forks – Pitch – Frequency – wavelength

In scientific terms, the speed of a tuning fork's vibrations is known as its frequency, a quantity measured in hertz (Hz), or vibrations per second.

The faster it vibrates the higher the perceived pitch.

Which tuning fork would have the

-longest Wavelength?

-lowest pitch?

-lowest frequency?

Why is the sky blue? Scattering!

Astronomy

• Universe • Stellar Evolution • H-R diagram • Sun • Moon • Motions

Rotating Earth

• Rotation describes the earth spinning on an axis

• How long for 1 rotation? 24 hrs • Earth rotates from west to east - causing sun to appear to rise in east

Revolving Earth

• Revolution describes the earth’s orbit around the sun.

• How long for 1 revolution? 365 days • Travels in an ellipse with aphelion and

perihelion (150 million km avg.)

The Tilted Earth • The earth is tilted at a

23.5° angle to the plane of its orbit

• What if the earth was

not tilted? day and night would

be equal everywhere

http://www.chavie.com/axistilt.jpg

• Summer Solstice – June 21, 22 - longest day light • Winter Solstice - Dec. 21, 22

- shortest daylight

Kepler’s Laws

A visual of Kepler’s 2nd law

http://homepage.smc.edu/balm_simon/images/astro%201/GRAVITY/keplers_2nd.jpg

Brightness

• Absolute Magnitude: true brightness if all stars were seen from 32.6 light years away.

• Apparent Magnitude: the brightness of a star as it appears from earth.

Fusion • Pressure causes

temperature to increase • At 10,000,000 C, nuclear

fusion begins in the core.

– Protostars become real stars (MS)

– Hydrogen helium – Helium Carbon (Giants) – Carbon Magnesium

Iron (Supernova) -Neutron Stars are super heavy: weigh 100

million tons on earth and rotate rapidly

FUSION! A star’s energy source!

Galaxies Bound together by gravitational attraction.

Contain stars, gas, dust clouds, or nebulae.

Estimated 50 billion and 1 trillion galaxies.

Milky Way is our galaxy (spiral)

100,000 light-years in diameter

2,000 light-years thick

Final Pic

The Sun’s Atmosphere

1.)Photosphere • 6000 C

• “Surface” layer – Radiates visible

light

• Granulation from convective zone

The Big Bang

1. Redshift of Galaxies

2. Microwave Background

3. Mixture of Elements

4. Looking back in time

Inflation

Dark Energy

28.3 Formation of the Solar System • Nebular Theory:

– The entire solar system formed at the same time & from the same spinning nebula.

Big Bang (13.7bya) Solar nebula formed 4-5bya sun began to form planets formed in the nebula’s outer regions, planetesimals protoplanets (more gravity) moon formed

Planets • INNER

– Mercury – Venus – Earth – Mars

• OUTER – Jupiter – Saturn – Uranus – Neptune – Pluto

• . Asteroids

Comets

Satellites Moons

The SUN

Nebular Theory

Impact Theory: How we got our moon….

http://www.atsweb.neu.edu/physics/e.sassaroli/Lunar_phases.jpg

http://home.cwru.edu/~sjr16/media/eclipse_solar.jpg

Weather and Atmosphere

Conduction and Convection

• Conduction: transfer of energy by vibrating molecules directly touching. – Molecules move faster when they’re heated

• Convection: Movement of gases or liquids when heated unevenly. – Cold air sinking, warm air rising helps heat

Earth’s surface evenly. • WINDS are created by:

– Pressure lowers under warm air masses – Cool air moves to low pressure regions.

Layers of the Atm.

• Differ by temperature and altitude

• As altitude increases, air pressure decreases.

• See page 460

http://www.ipsl.jussieu.fr/services/Observations/images/imagesNDSC/atmospheric_layers.jpg

Greenhouse Effect • Long wavelengths (infrared

rays) trapped • Atmosphere TRAPS heat

energy and cannot escape back into space. – Result Warms Earth’s

surface – Human activity can change the

balance & cause the avg. temp. to increase .

– Global warming can lead to climate changes.

What is an air mass?

Symbols

Low Pressure Systems

*Wave Cyclones* • Travel West to East

across the US – Westerly Winds

• Low Pressure (warm

air rises up off of the ground) – Clouds and stormy weather probable.

• Cyclones (tornadoes, hurricanes) – Spin

counterclockwise – Air moves upward – Air moves in.

Reading a weather map: Forecasting

ISOBARS

Figure 1. Large scale winds are deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This deflection is due to the Coriolis effect.

• Salinity of the Oceans

http://www.at-sea.org/missions/append/docs/thermocline.jpg

Thermocline

: Zone of rapid temperature drop!

Marks the distinct separation between the warm surface water and the colder deep water.

Gulf Stream

Land Breeze: Sea Breeze

Land temperatures change easier that water temperatures.

Heat absorption and Release • The way solar energy strikes earth and is

absorbed or released influences temp. – Land vs. Water:

• Land warms faster (unmoving) • Water warms slower (waves, currents keep mixing) • Water takes more energy to warm 1 degree

(specific heat) • Water releases heat more slowly

– Evaporation • More water evaporates over water than over land • Evaporation is a cooling process

Land and sea breezes:

*Land surface heat more in daytime, cools more at night ►

Results in diurnal reversal in wind directions

► Pattern reverses at night after land becomes cooler than ocean

No wind when land and ocean temperatures comparable

Surface heating initiates upward expansion over land

Cellular circulation develops and strengthens during afternoon

Ocean Currents • Currents influence air that contacts it. • Winds towards shore… away from shore...

– N.Europe: big influence, U.S. not much.

www.ldeo.columbia.edu/.../ ocean_index.html