Regents Earth Science

Essential review

Students will receive copies of these review guides individually, I have put them all online as just one guide. These are the most essential facts from each unit, and every student should know everything that appears on them. This is the base knowledge used in preparing the regents exam. This should be the starting point for each unit review, but it should not replace using old note packets, tests and quizzes to study from as well. The regents tends to repeat the same questions year after year, so by looking at practice questions, and mastering those, students will be in good position to conquer the regents. Students will be receiving practice questions on each of these units, and we will cover each in class.

Unit 1- Intro

- An observation is any sort of information that can be determined by your senses. (reading a thermometer, observing a book is red)

- An inference is a prediction or determination based one or or more observations. (It is going to rain tomorrow, these footprints are from a deer)

- Density is equal to mass divided by volume. You can use this formula to solve for any of the three variables.

- Percent Error is measured by determining how far off you were from the accepted value. Divide that by the accepted value. Then multiply by 100. Make sure you divide by the correct value, not the incorrect value.

- On a graph, a steep slope means a fast rate of change.

- Energy is transferred in the following ways

o Radiation- When light passes straight through an object, usually air or space.

o Conduction- When heat is transferred through a solid. (Like a medal bar)

o Convection- Usually happens in a fluid. The object heats up, rises, then cools, and sinks. This is usually shown as a circular pattern.

- Energy is transferred from energy highs, to energy lows.

- When an object is in motion, that is kinetic energy, when it is at rest, it can have potential energy due to its position or composition.

- A classification system helps us to organize data in a meaningful way.

- Mass is not how much an object weighs, it is how much matter is in an object.

- Entropy is the tendency for objects to fall apart. (From order to disorder)

- Changes can either be cyclic or noncyclic, predictable or unpredictable.

Unit 2- The earth

- The earth is an oblate spheroid. This means it is slightly wider in the middle than it is from pole to pole. However, if you looked at a picture of it, it would look like a perfect circle.

- On a contour map, the amount the elevation changes between two lines is called the contour interval. It is often labeled on the bottom of the map, or you can compare two lines that are labeled. Also, the ocean has an elevation of 0.

- When a river passes a contour line, the “V”’s point upstream, and the river flows downhill.

- The gradient is found by finding how much your elevation changed, then divide by how far you moved horizontally. Look at the contour lines to determine how far up or down you went, use the scale to find out your horizontal change.

- Where the contour lines are the closest together, the hill is the steepest.

- Polaris is a star directly above the north pole. If you were at the north pole, it would be 90 degrees above you. If you were on the equator, it would be at 0 degrees. If you lived 20 degrees north of the equator, the start would be 20 degrees above the horizon. As you move west and east, the star does not move.

- Lines of latitude run sideways around the globe (think ladder) They tell you how far north or south of the equator you are. The number varies from 0-90

- Lines of longitude run up and down the globe (think long) They tell you how far east or west you are from Greenwich England. The number varies from 0-180

- Degrees each have 60 smaller units in them called “minutes”.

- A Foucault pendulum proves that the earth is rotating. So does the coriolis effect.

- 15 degrees of longitude is how far the sun moves in one hour.

Unit 3- Rocks and Minerals

- Minerals are objects with their own uniform atomic composition. They each have unique chemical and physical properties which is based on their atomic structure. A mineral must be naturally occurring.

- Rocks are made of one or more minerals. Most of the rocks on earth are made up of the same 12 minerals.

- Properties of minerals include:

o Luster- It looks metallic or non metallic

o Cleavage- If it breaks along one or more specific planes, or if the breaks are random

o Hardness- You can test this by scratching it against a penny, a fingernail, a nail, or a pane of glass.

o Streak- When you scratch the mineral against a porcelain plate, what color trail does it leave? This is more reliable than just looking at the sample.

o Density- Because each mineral is made up of one atomic structure, each has their own unique density that is not effected by the samples size.

- Rocks are classified based on how they are formed.

- The Rock cycle shows how rocks change from one type to another.

o Igneous rocks are formed when molten rock cools and hardens. They are the first, and most common rock on earth, but most igneous rock is buried.

o Sedimentary rock forms when other rocks get broken up, the packed back together. They might also form when water evaporates leaving behind a solid solution. They are on the surface of the earth.

o Metamorphic rock forms when another rock is exposed to high heat or pressure. The rocks characteristics change. It is not heated up enough to melt completely.

- Identifying igneous rock

o You want to look at the size of the grains, and the color of the rock.

o As the magma cools, the crystals grow. If it takes longer to cool, you get bigger crystals. So rocks that cool quickly at the earths surface have small crystals, rocks that cool slowly deep inside the earth have big crystals.

o Dark colored rocks are high in density and mafic in composition. Light colored rocks are low in density, and felsic in composition. Read the mineral chart to find out what minerals are in what rocks.

- Identifying sedimentary rocks

o There are three main types. Clastic, which is made up of individual grains, this is classified based on the size of those grains.

o Crystalline rocks look like a series of crystals locked together. It is formed when water evaporated and material is left behind.

o Bioclastic rocks are made up of formerly living matter. Limestone is shell fragments cemented together. It bubbles in acid. Coal is a dark rock, that is lighter than it looks. It is made from plant remains.

- Identifying Metamorphic rocks.

o Rocks are either foliated, which means it looks like they have bands or layers of rock. These ones were formed by high pressure. Or they are non foliated, and it looks like different crystals held together like a jigsaw puzzle. These were formed by high heat.

o From there, you need to look at the grain size. Any other information is usually given to you in the question and you need to use your reference tables to figure it out.

Unit 4- The Dynamic Crust

- We know what is going on below the ground by using seismic waves.

- The current theory is plate tectonics and continental drift. It states that there are plates of crust moving around the earths surface. Proof is…

o Rocks and fossils on opposite sides of oceans match up. The continents also seem to fit together.

o On the sea floor, the magnetism of the rocks on either side of an ocean ridge reverse in a symmetric pattern on either side. Rock closest to the ridge is youngest

o Creatures that ordinarily found in oceans are found in rocks which are now well above sea level.

- Continental crust is different from oceanic crust. Continental crust is made up of mostly granite. It is thicker, and less dense. The ocean floors are mostly made up of basalt. It is thinner, and more dense.

- There are three types of waves in an earthquake.

o P-Waves travel fastest, and can go through pretty much anything

o S- Waves are slower, and can only go through solids. Because S waves cannot travel through the outer core, we have inferred that it is a liquid.

o Surface waves are slowest, and only felt near the quake.

- Because we know the speed that these waves travel, we can determine how far away an earthquake occurred based on the difference between the two waves arriving. Use your reference tables on these questions. If you want to pinpoint the location of an earthquake, you need at least 3 stations to report.

- We believe there are giant convection cells within the mantle. The mantle is “plastic” and capable of motion. Rock heats up and rises, cools down and sinks. The plates on the crust ride along the top of these hot convection currents like crust on a soup. Sometimes the hot material reaches the surface, and we have volcanoes.

- When two plates collide, ocean crust will sink below continental crust. This causes earthquakes that get deeper and deeper as you move away from the trench. Farther away from the trench, you tend to get a line of volcanoes and molten rocks reaches the surface again.

- Earthquakes are most common at plate boundaries.

- A divergent plate boundary is where plates are moving in opposite directions. This is most common in the middle of oceans.

- A convergent boundary is where two plates collide. If they are both continents, then mountains will be built. Otherwise, one of the ocean plates will sink.

- Transform boundaries are where two plates are sliding past each other. Like in California.

Unit 5- Erosion and deposition

- There are two types of weathering

o Chemical weathering, where an object is actually physically changed from one substance to another. This usually is caused by exposure to water. It is the most common in warm, moist climates. When the particles are smaller, there is more surface area, and faster weathering.

o Physical weathering is when the object maintains it’s properties, but it is broken down into smaller pieces. This is more common in colder climates, where water can get into cracks and then freeze, expanding the crack.

- Erosion is the actual transportation of particles. Gravity pulls all the particles down.

- Ice erosion is caused by glaciers, rivers of ice. They act like a giant bulldozer, pushing and carrying rock. When the glacier melts, it leaves everything in an unsorted pile. It often leaves parallel scratches in a rock.

- Water can carry particles by dissolving them. Smaller particles will be carried along with the water. Larger particles are moved along the bottom. During a flood, a river can move the largest particles. Objects transported in water become rounder the longer they are moved for.

- Wind can also pick up and move small particles.

- When a stream slows down, the largest particles settle to the bottom first. This creates sorting. If it slows down at a low rate, the sorting will take place horizontally, where the bigger particles will be farther upstream, and the smallest particles at the delta. If it is a flood, then the layers will be one on top of the other.

- Denser particles settle faster also, as to heavier and less round particles.

- Early on, when a river is just coming down out of the mountains, it travels quickly, and the gradient is usually pretty steep. The path of the stream is usually straight, and you get more erosion than deposition.

- As the river reaches flatter areas, it slows down. It starts to curve back and forth. Deposition becomes more common. The fastest part of a river on a straight section is just below the surface in the middle. If it is a turn, then the outside of the turn is the fastest, and you get more erosion there. The inside is the slowest, and you get more deposition.

- The space between particles in the ground is called porosity.

- How easily water gets through a rock is called it’s permeability.

- How much water sinks into the ground is called infiltration. Water that doesn’t sink into the ground is runoff. The harder it rains, the steeper it is, the lower the permeability, all cause more runoff.

- Landscapes are formed based on the surface bedrock. They type of landscape dictates the stream patterns found on it.

Unit 6- Geologic History

- A sequence of geologic events can be interpreted using a simple set of rules.

o Assuming the layers haven’t been overturned, rocks found below other layers are older. The youngest rocks are on top.

o Anything that changes a layer must be younger than it. A layer must be older than a fault across it.

o When igneous rock is intruded, it will cause metamorphism with any rock it touches. So if there is metamorphism, the other rock must have been there first.

- You can follow one rock layer to correlate it to other rocks. Correlate means comparing the ages. This can be done in either a relative sense, or you can determine the exact ages.

- Volcanic ash can be used to date rock. An eruption covers a large area quickly, so when you find it, you can easily date it.

- Index fossils are fossils that live for only a short amount of time, but cover a large area.

- Most of geologic history is the Precambrian period. However, since life was rare, soft and small, we don’t have a lot of fossil evidence from this time period. In the Paleozoic, many life forms started to evolve quickly and started to live on the land. In the Mesozoic, reptiles and birds took over as the dominant creatures. The planet was hot and wet. This era ended when an asteroid destroyed the dinosaurs. The climate cooled off, and mammals were able to take over the planet. We are in this age.

- A gap in the erosional record is an unconformity. The land was probably above water, and new rock was not formed, or has since been destroyed. Sedimentary rock is mostly deposited below water.

- Certain elements are unstable, they are radioactive isotopes. They decay at a predictable rate. But every element is different.

- A radioactive element decays from a parent to a daughter. By looking at the ratio between the two, you can determine how long it has been decaying for.

- A half life is how much time it takes for half an element to decay. A half life is constant. Carbon has a short half life, so it is only useful on recent fossil or rock. It’s best for formerly living things. Uranium is best for old, igneous rock.

Unit 7- Weather

- Insolation is energy that comes from the sun to the earth. The wavelength of the energy effects what type of energy it is. The short wave radiation is filtered out by the atmosphere. Visible light is what comes through to the earths surface. Stuff absorbs the light, then reradiates it as infrared energy.

- The sunlight provides energy for evaporation. Water evaporates easier when it has a large amount of surface exposed, it is warmed, stirred, and wind is blown over the surface.

- The divisions in the atmosphere are based in changes in temperature. In general, as you go higher, air pressure decreases and the amount of water in the air decreases.

- Air pressure is a measure of the weight of the air above a certain point.

- Wind blows from areas of high pressure to low pressure.

- Cold air contracts, making it denser, warm air expands, making it less dense.

- As warm air starts to rise, it cools naturally. Warm air can hold more water than cold air.

- Relative humidity is a measure of how much water is in the air compared to how much it can hold. The dewpoint is the temperature at which is can hold no more. As the temperature gets closer to the dewpoint, humidity goes up.

- When the air cools past the dewpoint, some of the water needs to come out of the gas phase. Small water droplets form, and we see clouds.

- As clouds get bigger, the droplets get heavier, and finally they fall as rain if the temperature is above freezing, and snow if it is below freezing. Tall clouds have giant convection cells, where it is freezing at the top and you get hail. If it is freezing at ground level, but not above, you can get sleet or freezing rain.

- A front is where two different air masses meet. The front is named after the type of weather you will have after the front passes, the symbols point in the direction the front is moving in. There are short violent storms associated with cold fronts, and slow steady rain with warm fronts. Occluded and Stationary fronts usually mean no rain for a while.

- On a weather map, isotherms connect points of equal temperature, isobars connect lines of equal pressure.

- The info for a weather station model is on page 13 of your ESRT. Be aware of where each part goes. The feather that shows you the wind is blowing in towards the station, not away from it. The three numbers they give you for pressure are the last 3. You need to put a decimal point in one from the end, then add a 9 or a 10 in front. The pressure will be closest to 1000.0

Unit 8- Climate

- A air mass comes from a specific source region. Each one has their own properties. There are two factors that go into describing an air mass, temperature and humidity.

- Warm air masses form closer to the equator, cold air masses form closer to the poles. If it is humid, it formed over water, if it’s dry, it formed over land.

- The two letter designations are found in your reference tables.

- As you move farther from the equator, climate gets colder and dryer.

- As you move higher in elevation, it gets colder and dryer.

- If you are on the windward side of a mountain range, it is cold and wet as air is forced to rise over the mountains. If you are on the leeward side, it’s warm and dry.

- Water has a moderating effect on climate. It stays cooler in the summers, and warmer in the winters.

- Ocean currents can bring warm or cold water from one area to another.

- There are set planetary wind belts, as well as specific areas where air rises and sinks. This is on page 14 of the ESRT. Low pressure is where air is wet and rising.

- Monsoons are seasonal patterns on large continents. It is dry 6 months of the year, then wet.

- The coriolis effect provides proof the earth rotates. Objects in the northern hemisphere are deflected to the right. In the southern hemisphere they go left. Because of this, low pressure systems rotate counterclockwise, and high pressure goes clockwise.

- Our weather in the US comes from the southwest. Storms move towards the northeast. That’s because of the wind belt.

- How much light gets absorbed by the earth depends on how long the sun is up for, and the angle it comes in at. If it is at a high angle, we will heat up more. The earth is tilted and revolves around the sun, so we get different seasons and climates on earth.

- It takes time for the earth to heat up and cool down. That is why it is not the warmest right at noon, and not the hottest on June 21^st.

- Dark surfaces heat up and lose heat quickly. Same with rough surfaces. Water heats up slower than land because it has a higher specific heat.

Unit 9- Universal Astronomy

- There are two models for the Solar system

o The Geocentric model stated that the earth was at the center and motionless. Everything revolved around us. This explains why the sun rises and sets, it explains the phases of the moon. But it never explained the motions of other planets, or the coriolis effect.

o The Heliocentric model was adopted next and is currently used. It placed the sun at the center, and everything moves around that.

- By looking at the light waves that come from a distant star, we can determine it’s wavelength and what it is made from. Also, we can see a Doppler effect. An object moving away from us will take on a slightly redder color. Most objects are red shifted. The Universe is expanding. The farther away the star is, the longer it takes the light to get here, so the longer back in time we are looking.

- Keplers three laws tell us objects do not move in perfect circles, they move in ellipses. An ellipse has two center points called foci. Eccentricity is the measure of how non-circular an ellipse is. You calculate it by dividing the distance between the two center points by the distance across the middle of the ellipse. A number closer to 0 means it’s more circular, a number closer to 1 means it’s flatter. Most planets orbits are closer to 0.

- Kepler also told us that orbits cover equal areas in equal time.

- Also, as a planet orbits the sun, it gets closer to and farther away from it. When it is closest, it goes the fastest, and the sun looks the biggest. As it gets farther away, the sun starts to look smaller and the planet revolves slower.

- Gravity is the mass of the two objects divided by the distance squared. Because distance is squared, it plays a bigger role than the mass of the object.

- Stars are objects that give off their own light. The energy comes from fusion, which is going on inside the star.

- The size of the star effects the kind of life it will live. Most stars are main sequence stars, as they die, they get bigger, and then collapse into a tiny star or black hole.

- Galaxies are groups of billions of stars. There are billions of galaxies in the Universe.

- Stars and other objects rise in the east and set in the west. They move across the sky at a rate of 15 degrees an hour, which is the speed the earth rotates.

Unit 10- Solar system Astronomy

- In your reference tables, you can look up detailed information for each of the planets, the moon and the sun. Use it!

- Almost all the objects in the solar system rotate and revolve from west to east.

- Solar noon is when the sun reaches it’s highest point in the sky. The sun is never directly overhead in NY, it is always to our south. It is always within 23.5 degrees of the equator, because that is the tilt of the earth.

- The sun is farthest north on June 21^st, the first day of summer, March and September 21^st it is right over the equator, it is farthest south on December 21^st. The earth takes time to heat up and cool down.

- Half the moon is always lit. If the entire lit half is facing the earth, we see a full moon. For the next 14 days, we see less and less of the moon until the lit half is facing away, that’s the new moon.

- The side of the earth facing the moon is experience high tide. So is the side facing away from it. In between, is low tide. The moon plays a more important role than the sun because the moon is so much closer. When the moon and sun align, we get a higher tidal range. When they form a right angle, we get the smallest tidal range.

- When the moon gets between the earth and sun, we could have a solar eclipse. When the earth is between the moon and sun, we could get a lunar eclipse. They do not happen every month because the moons orbit is tilted.