The winter solstice occurs on _______________________ sun North Pole

Winter Solstice December 21 Sun rises south of east Sun sets south of west Sun’s altitude is lowest of year (longest shadows) Vertical rays (90*) at Tropic of Capricorn (23.5*S) NYS 9 hrs of daylight/North Pole=0

The summer solstice occurs on ______________________ sun North Pole

Summer Solstice June 21 Sunrises north of east Sunsets north of west Sun’s altitude highest of year (shortest shadows) Vertical rays(90*) at Tropic of Cancer (23.5*N) NYS gets 16 hrs of daylight/North Pole=24

The equinoxes occur on _________ & ___________ sun North Pole

Equinoxes March 21 & Sept 21 Sun rises due east Sun sets due west Vertical rays (90*) at the equator 12 hours of daylight & 12 hours of nighttime everywhere on Earth

The true shape of the Earth is an

Oblate sphere Slightly flat at poles Bulges slightly at equator

The best evidence for the roundness of the Earth is

Photos from space

Other evidence of roundness Ships that appear to sink as they move over the horizon Polaris gets higher in the sky as you go north and lower as you move south Earth’s shadow on the moon during a lunar eclipse

The Earth appears to be

Perfectly round

The driving force behind plate tectonics is

Convection currents in the mantle

Convection currents are also found in the atmosphere and in bodies of water water atmosphere

The youngest rocks are found at _____ and the older rocks are found near the ______

The youngest rocks are at or near the mid-ocean ridge since new crust is being formed here. The older rocks are found closer to the edge of the continents. Picture of mid-ocean ridge in Iceland.

The weather associated with a high pressure system is

Clear, cool and dry (fair)

The circulation in a high pressure system (in northern hemisphere) is

Clockwise and outward

The weather associated with a low pressure system is

Cloudy, rainy and warm

The circulation in a low pressure system (in northern hemisphere) is

Counterclockwise and inward

How many seismograph stations are needed to find the epicenter?

3

The 500 rule says

If over 500 add a 9 If below 500 add a 10 Don’t forget the decimal and units (mb)

Minerals are composed of atoms

Rocks are composed of minerals

Minerals are

Naturally occurring Inorganic Solids Have definite chemical composition Definite crystalline shape (internal arrangement of the atoms)

Minerals are grouped by Chemical composition The silicon oxygen tetrahedron is the most common and it is pyramid shaped.

Physical properties of minerals (luster, cleavage/fracture and hardness) are determined by the

Internal arrangement of atoms

Rocks are classified by

Their origins

Sedimentary rocks Compaction (burial) & cementation

Igneous rocks Melting & solidification of magma or lava

Metamorphic rocks Heat & pressure

Intrusive igneous rocks Form ______ and cool __________

Intrusive igneous rocks Form underground and cool slowly Large crystal sizes

Extrusive igneous rocks Form at the ________ and cool _______

Extrusive igneous rocks Form at the surface and cool quickly Small crystals, no crystals or vesicular (gas pockets)

Continental crust is made of ___ and ocean crust of _______

Granite (thick) Basalt (thin)

Fossils are found in

Sedimentary rocks

Contact metamorphism Occurs when rocks come in contact w/magma or lava

Regional metamorphism Occurs over a large area is most often associated with mountain building.

Most earthquakes and volcanoes occur at or near plate boundaries

P waves Primary waves (compressional or back & forth) Fastest Arrive first Travel thru solids and liquids

S waves Secondary waves (side-to-side or shear) Arrive second Travel slower Travel thru solids only

Interior properties of the mantle and core are inferred from eq waves The inner core is solid due to intense pressure The outer core is liquid

Measuring Eq’s The Richter scale measures the amount of energy released by the eq The Mercalli scale measures intensity based on damage reports

3 plate boundaries Divergent – move away & features mid- ocean ridges and rift valleys, new crust is formed

3 plate boundaries Convergent – collide, old crust is destroyed –3 types Ocean v. ocean = deep ocean trenches & volcanic island arcs ex. Japan, Aleutian Islands Continent v. ocean = ocean trenches, volcanic mountain chains ex. Cascades & Andes Continent v. continent = earthquakes & very tall mountain ranges ex. Himalayas

Weathering is the breaking down of the rocks Erosion is the transportation of sediments

Physical (mechanical) weathering breaks the rocks into smaller pieces Chemical weathering changes the composition

Warm & humid (moist) climates favor chemical weathering Cold & humid climates favor physical weathering Weathering is slow in dry climates

Factors affecting weathering rates The more surface area the faster the weathering takes place Composition

Soils Form because of weathering & biologic activity The topsoil (a horizon) contains the darker soil and nutrients The subsoil (b horizon) is reddish in color due to the presence of clay particles that have been leached from the topsoil The c horizon is partially weathered bedrock

Agents of erosion running water – most effective & dominant Glaciers Wind Ocean waves Mass movement (creep, slump, landslide, etc. The major force behind all erosion is gravity!

The closer the isolines the steeper the slope. On a weather map, the closer the isolines the faster the wind blows.

Stream velocity depends on Slope (gradient) Volume (discharge) Shape of the channel

The outside of the meander is faster and erodes The inside of the meander is slower and deposition occurs

As the velocity of a stream increases, so does the particle size being carried As the discharge increases so does the velocity If the velocity decreases deposition occurs

A stream carries it load by Solution Suspension Bouncing & rolling & dragging Abrasion is the process that rounds & smoothes the pebbles because they are bouncing and banging into one another

Running water Sorts its material by size In a horizontal cross-section the larger particles are closer to shore and smaller particles are farthest from shore in deeper water In a vertical cross-section the larger material will be on the bottom and the smaller material on the top

River Valleys Are v shaped

Glacial valleys Are U shaped Other evidence of glaciers –Erratic (boulders) –Till – unsorted sediments –Eskers, kames, drumlins, moraines –Striations – parallel scratches in bedrock –Hanging valleys, kettle lakes & finger lakes –Lakes & drumlins tell direction of ice mov’t

Gravity deposits Are unsorted (talis)

Rock layers that are resistant to weathering stick out or form cliffs while less resistant rock layers form valleys and are worn back

In undisturbed rock layers All layers are deposited horizontally first (law of original horizontallity) The oldest rocks are on the bottom (superposition) Faults, folds and intrusions are younger than the rocks they are found in (cross- cutting relationships) Fossils are at least as old as the rocks they are found in (flora & fauna)

Index Fossils Used to determine relative dates of rocks Must be geographically widespread Have a geologically short life span

Geologic Time Is divided into units based on the fossil record An unconformity is a buried erosional surface and represents a gap in the rock record

Half-life The half life of a substance can not be changed. Carbon 14 is used for recent dating (less than 50,000 years) 1 half life = 50%, 2 half lives = 25%, etc.

Air Warm air holds more moisture than cold air Warm air is less dense than cold air therefore it rises! As altitude increases, pressure decreases

Wind Winds are named for the direction from which it blows Winds always blows from high to low pressure

Weather The closer the air temp and dew point the greater the chance for precipitation A rising barometer = good weather, a falling barometer = poor weather Fronts occur where air masses meet The greater the difference in characteristics of air masses the greater the chance for severe storms

Weather con’t Precipitation occurs where air is forced to rise ex. Low pressure system, along a front, windward side of mountain, itcz Hi pressure = clockwise and out Low pressure = counterclockwise and in Marine climates have warmer winters and cooler summers than continental climates Weather in US usually moves west to east (with slant to ne)

Weather con’t mP – moist and cold – northern oceans cP – dry and cold –northern Canada mT – moist and warm – warm oceans and gulf of mexico cT – warm and dry – deserts of sw USA cA – very cold and very dry – extreme northern Canada in winter only

Hurricanes Form over warm ocean waters, need moisture for energy June1-nov 1 Extreme low pressure system As pressure decreases, wind increases Danger from storm surges, flooding and wind evacuate

tornadoes Usually early spring but anytime Mostly in mid-west but anywhere Most likely when mT air from gulf collides with cP air from Canada Narrow path of destruction compared to hurricanes

rotation Spin on axis Earth rotates once every 24 hours Rotation rate = 15 degrees per hour

revolution Movement around the Sun 1 revolution = 356 ¼ days Revolution rate = ~ 1 degree per day Ellipitical orbit w/ sun at one foci The closer we are to the sun the faster we go. Closest to sun in winter (jan 1) farther in summer (july 1)

Polaris The altitude of polaris = your latitude Look north to see polaris All stars and constellations appear to rotate counterclockwise around polaris

seasons Caused by –Tilt of earth on axis –Revolution around the sun –Parallelism

insolation Sun’s rays most intense at 90 degrees Shadows are longer when sun is lower on horizon The higher the angle of insolation the warmer the temps In the US you look south to seen the sun in the afternoon Sunrises in east sets in west

atmosphere Earth receives shortwave energy from sun which becomes longwave when reflected by surface Greenhouse gases are carbon dioxide, methane and water vapor

moon The moon revolves around the earth in about 29 ½ days Seen by reflected sunlight Solar eclipse at new moon, lunar eclipse at full moon Tides are highest and lowest at new and full