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Core Content and Skills
Science Earth Science 8 
2007-2008
BOE Approved

Introduction to the Earth's Changing Environment  Content   Skills  Observations can be obtained by using one of the senses or by direct measurement with an instrument. Inferences are decisions made based on observations. Density = Mass/Volume Objects with higher densities will tend to sink below objects that have a lower density. Graphs can be used to demostrate the relationship between two or more variables   Using graduated cylinders containing different fluids, an electronic balance and a calculator, students will determine the mass, volume and density of fluids and will apply that information to demonstrate an understanding of relative density. The student will construct a line graph of average settling time vs. particle diameter and predict the settling time for another particle of given diameter.

Measuring Earth  Content   Skills  Earth's coordinate system of latitude and longitude, with the equator and prime meridian as reference lines, is based upon Earth's rotation and our observation of the Sun and stars. Earth rotates on an imaginary axis at a rate of 15 degrees per hour. To people on Earth, this turning of the planet makes it seem as though the Sun, the moon, and the stars are moving around Earth once a day. Rotation provides a basis for our system of local time; meridians of longitude are the basis for time zones. Topographic maps represent landforms through the use of contour lines that are isolines connecting points of equal elevation. Gradients and profiles can be determined from changes in elevation over a given distance.   Locate US and International cities on maps using latitude and longitude. Determine the time of day based on angular motions of the sun across the sky Use the altitude of Polaris above the Northern Horizon to determine the latitude of the observer. Determine time difference between 2 locations on Earth based on longitude differences. Determine the elevation of a location based on information on a topographical map Construct a geologic profile Calculate gradient between two points on a topographical map Given a field map of values, construct isolines

Earth In The Universe, Motions of the Earth, Moon  Content   Skills  Nine planets move around the Sun in nearly circular orbits. The orbit of each planet is an ellipse with the Sun located at one of the foci. Earth is orbited by one moon and many artificial satellites. The universe is vast and estimated to be over ten billion years old. The current theory is that the universe was created from an explosion called the Big Bang. Evidence for this theory includes: 1. cosmic background radiation 2. a red-shift (the Doppler effect) in the light from very distant galaxies. Stars form when gravity causes clouds of molecules to contract until nuclear fusion of light elements into heavier ones occurs. Fusion releases great amounts of energy over millions of years. The stars differ from each other in size, temperature, and age. Our Sun is a medium-sized star within a spiral galaxy of stars known as the Milky Way. Our galaxy contains billions of stars, and the universe contains billions of such galaxies. Our solar system formed about five billion years ago from a giant cloud of gas and debris. Gravity caused Earth and the other planets to become layered according to density differences in their materials. The characteristics of the planets of the solar system are affected by each planet's location in relationship to the Sun. The terrestrial planets are small, rocky, and dense. The Jovian planets are large, gaseous, and of low density. Asteroids, comets, and meteors are components of our solar system. Impact events have been correlated with mass extinction and global climatic change. Impact craters can be identified in Earth's crust. Most objects in the solar system are in regular and predictable motion. These motions explain such phenomena as the day, the year, seasons, phases of the moon, eclipses, and tides. Gravity influences the motions of celestial objects. The force of gravity between two objects in the universe depends on their masses and the distance between them. Earth's changing position with regard to the Sun and the moon has noticeable effects. Earth revolves around the Sun with its rotational axis tilted at 23.5 degrees to a line perpendicular to the plane of its orbit, with the North Pole aligned with Polaris. 1.1e The Foucault pendulum and the Coriolis effect provide evidence of Earth's rotation. 1.1f Earth's changing position with regard to the Sun and the moon has noticeable effects. o Earth revolves around the Sun with its rotational axis tilted at 23.5 degrees to a line perpendicular to the plane of its orbit, with the North Pole aligned with Polaris. ¥ During Earth's one-year period of revolution, the tilt of its axis results in changes in the angle of incidence of the Sun's rays at a given latitude; these changes cause variation in the heating of the surface. This produces seasonal variation in weather. 1.1g Seasonal changes in the apparent positions of constellations provide evidence of Earth's revolution. 1.1h The Sun's apparent path through the sky varies with latitude and season. 1.1i Approximately 70 percent of Earth's surface is covered by a relatively thin layer of water, which responds to the gravitational attraction of the moon and the Sun with a daily cycle of high and low tides.   Explain complex phenomena, such as tides, variations in day length, solar insolation, apparent motion of the planets, and annual traverse of the constellations. Describe current theories about the origin of the universe and solar system. Calculate eccentricity of planetary orbits Determine the altitude of the Sun on the equinoxes, as well as the summer and winter solstice. Draw and label a solar and lunar eclipse diagram

Energy In Earth Processes  Content   Skills  Earth systems have internal and external sources of energy, both of which create heat. The transfer of heat energy within the atmosphere, the hydrosphere, and Earth's interior results in the formation of regions of different densities. These density differences result in motion. Insolation (solar radiation) heats Earth's surface and atmosphere unequally due to variations in: 1. the intensity caused by differences in atmospheric transparency and angle of incidence which vary with time of day, latitude, and season. 2. characteristics of the materials absorbing the energy such as color, texture, transparency, state of matter, and specific heat 3. duration, which varies with seasons and latitude. The transfer of heat energy within the atmosphere, the hydrosphere, and Earth's surface occurs as the result of radiation, convection, and conduction. Heating of Earth's surface and atmosphere by the Sun drives convection within the atmosphere and oceans, producing winds and ocean currents.   Use the concepts of density and heat energy to explain observations of weather patterns, seasonal changes and the movements of Earth's plates. Measure temperature change with respect to time to determine how the angle of insolation affects the heating of the Earth Draw convection currents in the atmosphere to determine direction of wind along the surface

Weather  Content   Skills  Weather patterns become evident when weather variables are observed, measured, and recorded. These variables include air temperature, air pressure, moisture (relative humidity and dewpoint), precipitation (rain, snow, hail, sleet, etc.), wind speed and direction, and cloud cover. Weather variables are measured using instruments such as thermometers, barometers, psychrometers, precipitation gauges, anemometers, and wind vanes. Weather variables are interrelated. For example: 1. temperature and humidity affect air pressure and probability of precipitation 2. air pressure gradient controls wind velocity Air temperature, dewpoint, cloud formation, and precipitation are affected by the expansion and contraction of air due to vertical atmospheric movement. Weather variables can be represented in a variety of formats including radar and satellite images, weather maps (including station models, isobars, and fronts), atmospheric cross-sections, and computer models. Atmospheric moisture, temperature and pressure distributions; jet streams, wind; air masses and frontal boundaries; and the movement of cyclonic systems and associated tornadoes, thunderstorms, and hurricanes occur in observable patterns. Loss of property, personal injury, and loss of life can be reduced by effective emergency preparedness. Seasonal changes can be explained using concepts of density and heat energy. These changes include the shifting of global temperature zones, the shifting of planetary wind and ocean current patterns, the occurrence of monsoons, hurricanes, flooding, and severe weather.   Explain how incoming solar radiation, ocean currents, and land masses affect weather. Determine relative humidity and dewpoint temperature by using the Earth Science Reference Tables Construct air pressure and temperature maps using isobars and isotherms Use temperature maps to determine the location of weather fronts and air masses Use the Earth Science Reference Tables to convert temperature and pressure values Determine the cloud base height based on dewpoint and air temperatures.

Water and Climate, Weathering and Erosion  Content   Skills  Earth has continuously been recycling water since the outgassing of water early in its history. This constant recirculation of water at and near Earth's surface is described by the hydrologic (water) cycle. Water is returned from the atmosphere to Earth's surface by precipitation. Water returns to the atmosphere by evaporation or transpiration from plants. A portion of the precipitation becomes runoff over the land or infiltrates into the ground to become stored in the soil or groundwater below the water table. Soil capillarity influences these processes. A location's climate is influenced by latitude, proximity to large bodies of water, ocean currents, prevailing winds, vegetative cover, elevation, and mountain ranges. Temperature and precipitation patterns are altered by: 1. natural events such as El Nino and volcanic eruptions 2. human influences including deforestation, urbanization, and the production of greenhouse gases such as carbon dioxide and methane. Landforms are the result of the interaction of tectonic forces and the processes of continued weathering, erosion, and deposition. Weathering is the physical and chemical breakdown of rocks at or near Earth's surface. Soils are the result of weathering and biological activity over long periods of time.   Explain how incoming solar radiation, ocean currents, and land masses affect climate. Use knowledge of climate factors to describe the climate of locations on an imaginary continent

Deposition, Minerals, Rocks  Content   Skills  Natural agents of erosion, generally driven by gravity, remove, transport, and deposit weathered rock particles. Each agent of erosion produces distinctive changes in the material that it transports and creates characteristic surface features and landscapes. In certain erosional situations, loss of property, personal injury, and loss of life can be reduced by effective emergency preparedness. The natural agents of erosion include: 1. Streams (running water): Gradient, discharge, and channel shape influence a stream's velocity and the erosion and deposition of sediments. Sediments transported by streams tend to become rounded as a result of abrasion. Stream features include V-shaped valleys, deltas, flood plains, and meanders. A watershed is the area drained by a stream and its tributaries. 2. Glaciers (moving ice): Glacial erosional processes include the formation of U-shaped valleys, parallel scratches, and grooves in bedrock. Glacial features include moraines, drumlins, kettle lakes, finger lakes, and outwash plains. 3. Wave Action: Erosion and deposition cause changes in shoreline features, including beaches, sandbars, and barrier islands. Wave action rounds sediments as a result of abrasion. Waves approaching a shoreline move sand parallel to the shore within the zone of breaking waves. 4. Wind: Erosion of sediments by wind is most common in arid climates and along shorelines. Wind-generated features include dunes and sand-blasted bedrock. 5. Mass Movement: Earth materials move downslope under the influence of gravity. Patterns of deposition result from a loss of energy within the transporting system and are influenced by the size, shape, and density of the transported particles. Sediment deposits may be sorted or unsorted. The amount of precipitation that seeps into the ground or runs off is influenced by climate, slope of the land, soil, rock type, vegetation, land use, and degree of saturation. Porosity, permeability, and water retention affect runoff and infiltration. Sediments of inorganic and organic origin often accumulate in depositional environments. Sedimentary rocks form when sediments are compacted and/or cemented after burial or as the result of chemical precipitation from seawater. Minerals have physical properties determined by their chemical composition and crystal structure. Minerals can be identified by well-defined physical and chemical properties, such as cleavage, fracture, color, density, hardness, streak, luster, crystal shape, and reaction with acid. Chemical composition and physical properties determine how minerals are used by humans. Minerals are formed inorganically by the process of crystallization as a result of specific environmental conditions. These include: 1. Cooling and solidification of magma 2. Continued precipitation from water caused by such processes as evaporation, chemical reactions, and temperature changes 3. Rearrangement of atoms in existing minerals subjected to conditions of high temperature and pressure. Rocks are usually composed of one or more minerals. Rocks are classified by their origin, mineral content, and texture. Conditions that existed when a rock formed can be inferred from the rock's mineral content and texture. The properties of rocks determine how they are used and also influence land usage by humans.   Explain the properties of materials in terms of the arrangement and properties of the atoms that compose them.

Earth's Dynamic Crust and Interior  Content   Skills  Properties of Earth's internal structure (crust, mantle, inner core, and outer core) can be inferred from the analysis of the behavior of seismic waves (including velocity and refraction). Analysis of seismic waves allows the determination of the location of earthquake epicenters, and the measurement of earthquake magnitude. This analysis leads to the inference that Earth's interior is composed of layers that differ in composition and states of matter. The outward transfer of Earth's internal heat drives convective circulation in the mantle that moves the lithospheric plates comprising Earth's surface. The lithosphere consists of separate plates that ride on the more fluid asthenosphere and move slowly in relationship to one another, creating convergent, divergent, and transform plate boundaries. These motions indicate Earth is a dynamic geologic system. These plate boundaries are the sites of most earthquakes, volcanoes, and young mountain ranges. Compared to continental crust, ocean crust is thinner and denser. New ocean crust continues to form at mid-ocean ridges. Earthquakes and volcanoes present geologic hazards to humans. Loss of property, personal injury, and loss of life can be reduced by effective emergency preparedness. Many processes of the rock cycle are consequences of plate dynamics. These include the production of magma (and subsequent igneous rock formation and contact metamorphism) at both subduction and rifting regions, regional metamorphism within subduction zones, and the creation of major depositional basins through down-warping of the crust. Many of Earth's surface features such as mid-ocean ridges/rifts, trenches/subduction zones/island arcs, mountain ranges (folded, faulted, and volcanic), hot spots, and the magnetic and age patterns in surface bedrock are a consequence of forces associated with plate motion and interaction.

Interpreting Geologic History  Content   Skills  The evolution of life caused dramatic changes in the composition of Earth's atmosphere. Free oxygen did not form in the atmosphere until oxygen-producing organisms evolved. The pattern of evolution of life-forms on Earth is at least partially preserved in the rock record. Fossil evidence indicates that a wide variety of life-forms has existed in the past and that most of these forms have become extinct. Human existence has been very brief compared to the expanse of geologic time. Geologic history can be reconstructed by observing sequences of rock types and fossils to correlate bedrock at various locations. The characteristics of rocks indicate the processes by which they formed and the environments in which these processes took place. Fossils preserved in rocks provide information about past environmental conditions. Geologists have divided Earth history into time units based upon the fossil record. Age relationships among bodies of rocks can be determined using principles of original horizontality, superposition, inclusions, cross-cutting relationships, contact metamorphism, and unconformities. The presence of volcanic ash layers, index fossils, and meteoritic debris can provide additional information. The regular rate of nuclear decay (half-life time period) of radioactive isotopes allows geologists to determine the absolute age of materials found in some rocks. 1.2h The evolution of life caused dramatic changes in the composition of Earth's atmosphere. Free oxygen did not form in the atmosphere until oxygen-producing organisms evolved. 1.2i The pattern of evolution of life-forms on Earth is at least partially preserved in the rock record. o Fossil evidence indicates that a wide variety of life-forms has existed in the past and that most of these forms have become extinct. o Human existence has been very brief compared to the expanse of geologic time. 1.2j Geologic history can be reconstructed by observing sequences of rock types and fossils to correlate bedrock at various locations. o The characteristics of rocks indicate the processes by which they formed and the envi¬ ronments in which these processes took place. o Fossils preserved in rocks provide information about past environmental conditions. o Geologists have divided Earth history into time units based upon the fossil record. o Age relationships among bodies of rocks can be determined using principles of origi¬nal horizontality, superposition, inclusions, cross-cutting relationships, contact meta¬morphism, and unconformities. The presence of volcanic ash layers, index fossils, and meteoritic debris can provide additional information. o The regular rate of nuclear decay (half-life time period) of radioactive isotopes allows geologists to determine the absolute age of materials found in some rocks. 1.2e Earth's early atmosphere formed as a result of the outgassing of water vapor, carbon dioxide, nitrogen, and lesser amounts of other gases from its interior. 1.2f Earth's oceans formed as a result of precipitation over millions of years. The pres¬ence of an early ocean is indicated by sedimentary rocks of marine origin, dating back about four billion years. 2.1o Plate motions have resulted in global changes in geography, climate, and the patterns of organic evolution.

Landscape Development and Environmental Change  Content   Skills  Climate variations, structure, and characteristics of bedrock influence the development of landscape features including mountains, plateaus, plains, valleys, ridges, escarpments, and stream drainage patterns.