Unit 1 – EARTH MATERIALS SCIENTIFIC METHOD – 6 Step process that scientists use to investigate problems or questions – Includes: 1 – Problem Statement/Ask a Question 2. Gather information/research 3. Form a Hypothesis 4. Test the Hypothesis 5. Record data and analyze results 6. Draw conclusions/Communicate Findings Variables – things/factors that can change in an experiment o Constant/control – the factor that stays the same o Dependent – the factor that is being measured o Independent – the factor that is being tested/changed * Problem statement – should determine a cause/effect relationship – include an investigation that is testable _ independent and dependent variable (respectively) Hypothesis – an educated guess usually formulated in an “If______, then_______ statement. MEASUREMENT & SAFETY – SI Units – System of International Units – used by ALL scientists around the world – the metric system MATTER – anything that has mass and takes up space atoms: smallest particle of matter elements: made up of one or more atoms – substance that cannot be broken down into simpler substances compounds : made up of two or more elements – substance is joined by chemical bonds MINERALS - 4 main characteristics – naturally occurring, crystalline structure, inorganic (nonliving), & solid made of one or more elements Silicate – contain a combination of silicon and oxygen Nonsilicate – does not contain a combination of silicon and oxygen MINERAL TESTS Color – not very reliable Luster – the way light reflects on the mineral’s surface Streak – true color of mineral – rub the mineral across a porcelain plate Cleavage – how a mineral breaks – along smooth , flat surfaces Fracture – how a mineral breaks – uneven, curved, irregular surfaces Hardness – a mineral’s resistance to scratching – Moh’s Hardness scale – Diamond hardest known substance Density – how much matter is in an object/substance given amount of space ROCKS - naturally occurring, mixture of one or more minerals, organic (living), and solid Igneous – formed by cooling and hardening of magma o Intrusive – formed inside/below the surface- large/coarse grains – lots of time to form - granite o Extrusive – formed outside/above the surface – small/fine grains – very little time to form - basalt Sedimentary – rock that is formed by weathering, erosion, compaction, and cementation – has strata (layers) o Clastic – formed by depositing of sediment in layers - sandstone o Chemical – formed from solutions of dissolved minerals and water - halite o Organic – formed from the remains of animals or plants – limestone/coal Metamorphic – rock that is formed over time, under heat and pressure o Foliated – mineral grains arranged in planes or bands – gneiss o Nonfoliated – mineral grains are not arranged in a pattern – marble ROCK CYCLE – the continuous process by which new rock forms from old rock material – a cycle NATURAL RESOURCES- any natural material that is used by humans, such as water, petroleum, minerals, forests, and animals Renewable resources - a natural resource that can be replaced at the same rate at which the resource is consumed Nonrenewable resources - a resource that forms at a rate that is much slower than the rate at which it is consumed FOSSIL FUELS - a nonrenewable energy resource formed from the remains of organisms that lived long ago petroleum (oil) - extracted by drilling - formed from microscopic sea organisms - liquid form natural gas - formed from microscopic sea organisms - causes less pollution - gaseous form coal - sedimentary rock that forms from partially decomposed plant material ALTERNATIVE ENERGY RESOURCES Nuclear Energy - energy released by a fission or fusion reaction Chemical Energy - energy released when a chemical compound reacts to produce new compounds -hydrogen cell Solar Energy - energy received by the Earth from the sun in the form of radiation Wind Power - the use of a windmill to drive an electric generator Hydroelectric - electrical energy produced by falling water, damming up a river Biomass - organic matter that can be a source of energy - wood, gasohol Geothermal - energy produced by heat within the Earth - around volcanoes, geysers FOSSILS/GEOLOGICAL TIME Uniformitarianism – principle that states that geologic processes that occurred in the past can be explained by current geologic processes Catastrophism – principle that states that geologic change occurs suddenly Superposition – principle that states that younger rocks lie above older rocks if the layers have not been disturbed Geologic column – an arrangement of rock layers in which the oldest rocks are at the bottom - developed by piecing together different rock sequences from all over the world Unconformity – a break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long time Fossil – remains or physical evidence of an organism preserved by geological processes Trace fossils – a fossilized mark that is formed in soft sediment by the movement of an animal (tracks) Index fossils – fossil that is found in the rock layers of only one geologic age and that is used to establish the age of the rock layers FOSSILS ARE OFTEN USED TO INTERPRET THE PAST – CLIMATE CHANGES AND ENVIRONMENTAL CHANGES ***GEOLOGIC TIME – standard method used to divide the Earth’s long natural history into manageable parts ***GEOLOGIC EVENT – a catastrophic event that changed Earth’s climate and/or environment ex. (65 million years ago, the dinosaurs died out – cause possible asteroid impact WEATHERING AND EROSION WEATHERING - process by which rock materials were broken down by the action of physical or chemical processes Physical weathering – breaking down of rock by physical means o Ice wedging o Wind o Water o Gravity o Plants o Animals Chemical weathering – process by which rocks break down as a result of chemical reactions o Water o Weak acids o Air - oxidation o Lichen (fungi) CLIMATE AFFECTS WEATHERING – MORE MOISTURE, WIND, ELEVATION, AND MORE OR LESSTEMPERATURE = MORE WEATHERING ***SOIL – loose mixture of small mineral fragments, organic material, water, and air that supports growth of vegetation o Bed rock – layer of rock beneath soil o Parent rock – rock formation that is the source of mineral fragments in soil EROSION- process by which wind, water, ice, or gravity transports soil and sediment from one location to another o Water o Wind o Gravity o Waves o Glacier Unit 2 – Inside the Earth LAYERS OF THE EARTH Crust – thin, solid, outermost layer of the Earth o Continental crust o Oceanic crust Mantle – layer of rock between the Earth’s crust and core Core – center of the Earth below the mantle o Outer core – liquid o Inner core – solid and dense **The further you travel downward toward the core the more pressure, higher temperature. PHYSICAL STRUCTURE OF THE EARTH Lithosphere – solid, outer layer of Earth that consists of the crust and the rigid upper part of the mantle, broken into giant sections called tectonic plates Asthenosphere – the soft layer of the mantle on which the tectonic plates move Mesosphere – the strong, lower part of the mantle between the asthenosphere and the outer core CONTINENTAL DRIFT THEORY – hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present position Developed by Wegner Supercontinent called Pangaea Supported by the following evidence o Fossils o Climate o Rocks o Puzzle – like fi SEA-FLOOR SPREADING – process by which new oceanic lithosphere forms as magma rises toward the surface and solidifies Developed by Harry Hess Supported by the evidence of magnetic reversals THEORY OF PLATE TECTONICS – theory that explains how large pieces of the Earth’s outermost layer, called tectonic plates move and change shape Supported by Continental Drift Theory and Sea-Floor Spreading Theory THREE TYPES o Convergent Boundary – formed by the collision of two lithospheric plates Oceanic – oceanic – Indian Ocean – Earthquake Oceanic – Continental – forms a subduction zone – Ring of Fire – Volcanoes Continental – Continental – forms mountains – Himalaya Mount o Divergent Boundary – formed by two lithospheric plates that are moving away from each other ex. Atlantic Mid-Ocean Ridge – Mountain chain – forms new seafloor o Transform Boundary – boundary between tectonic plates that are sliding past each other horizontally ex. San Andreas Fault, CA causes many earthquakes POSSIBLE CAUSES OF TECTONIC PLATE MOTION Ridge Push – at mid-ocean ridges, oceanic lithosphere sinks and move downhill Convection – hot rock rises, but cooler rock sinks Slab Pull – oceanic lithosphere is denser than the asthenosphere, the edge of the plate pulls the rest of the tectonic plate with it GPS has tracked the movement of the plates – move about 3 – 10 centimeters per year – very, very slow DEFORMATION - process by which the shape of a rock changes because of stress Compression – when plates collide – convergent boundary Tension – when plates move apart – divergent boundary Folding – bending of rock layers due to stress EARTHQUAKES – the shaking of the ground when rock breaks Elastic deformation – rock stretched to its limit – leads to earthquakes Plastic deformation – deforms rock like clay or a rubber band – does not lead to earthquakes Elastic rebound - sudden return of elastically deformed rock to its undeformed shape SEISMIC WAVES – wave of energy that travels through the Earth away from the earthquake Body waves – travel through the interior of the Earth o P-waves – Primary – 1st – pressure waves – fastest – slow down when they reach liquid – move in a backand-forth direction – (slinky) o S-waves – Secondary – 2nd – shear waves – slower – stop when they reach liquid – move in a side-to-side direction Surface waves – travel along Earth’s surface – most destructive – moves up-and-down and back-and-forthmoves more slowly that S-waves- moves the ground much like ocean waves EARTHQUAKE MEASUREMENT o Seismograph – instrument to measure vibrations from an earthquake o Seismogram – the record or tracing of the vibrations from an earthquake Epicenter – the point on the EARTH’S SURFACE directly above an earthquake’s starting point Focus – the point INSIDE THE EARTH where an earthquake begins MEASUREMENT SCALES o Richter Magnitude Scale – developed by Charles Richter – 1 – 10 10 being the strongest Measures the strength of an earthquake o Modified Mercalli Intensity Scale – uses Roman Numerals I – XII (1 -12) XII being the most intense – measures how much damage and to what degree people felt the earthquake VOLCANOES – areas of the Earth’s surface through which magma and volcanic gases pass TYPES OF VOLCANOES o Shield – built by layers of lava during relatively quiet eruptions – broad bases, nonexplosive, not very steep, but can be enormous – Mauna Kea in Hawaii o Cinder Cone – built by layers of pyroclastic/cinder material – very steep sides, small, usually erupt for a short time, erode easily, loosely packed, moderately explosive – Paricutin, Mexico o Composite - most common type – form from alternating layers of pyroclastic, explosive and lava, quiet eruptions – can be very explosive – broad bases, sides that get steeper at top – Mount St. Helens, Mount Rainier, Washington State LAVA – Explosive eruptions are caused by a high water and silica-rich content in the magma – this causes a low viscosity (very thick, slow flowing) magma that often plugs the vents. Non-explosive – little water or silica content – high viscosity – (thin, flows easily) RING OF FIRE – outside edge of the Pacific Ocean – Most of the Earth’s 600 active volcanoes exist here, along the plate boundaries (convergent). HOT SPOTS – IN the middle of the plate, openings, not sure why they are there, Hawaiian Islands formed from Hot spot. Volcanoes can cause climate change – ash in atmosphere can block the sun and drop the global temperature. Unit 3 - HYDROLOGY OCEANS- 4 major oceans - Atlantic, Arctic, Pacific, & Indian **Oceans are thought to have formed when volcanoes erupted and spewed ash and gases into the atmosphere. This caused the Earth to cool and water vapor began to condense and caused torrential rains that filled up the deep basins. WATER CYCLE - evaporation, condensation, precipitation, & runoff 71% of Earth's surface is water 97% salt water 1.9% glaciers, ice packs .8% ground water .3% available fresh water Ocean water consists of salts and other dissolved solids - chlorine, sodium most of the salts. Oceans are salty because of runoff carried to the oceans by rivers and evaporation. OCEAN FLOOR continental shelf - gently sloping section located between shoreline and continental slope continental slope - steeply inclined section between the continental rise and the continental shelf continental rise - gently sloping section located between the continental slope and the abyssal plain abyssal plain - a large, flat, almost level area of the deep-ocean basin mid-ocean ridge - a long, undersea mountain chain that forms along the floor of the major oceans rift valley - a long, narrow valley that forms as tectonic plates separate seamount - a submerged mountain on the ocean floor that is at least 1000 m high and that has a volcanic origin ocean trench - a steep, long depression in the deep-sea floor that runs parallel to a chain of volcanic islands or a continental margin RESOURCES FROM THE OCEAN Living Resources Fish Seaweed Nonliving Resources Oil Natural Gas Tidal/Wave energy Minerals Desalination - process of removing salt from ocean water OCEAN MOVEMENTS CURRENTS - streamlike movements of water * Surface currents - caused by wind, Coriolis Effect, Continental Deflections Ex. Gulf Stream - warm current - makes England's climate milder Ex. California current - cold current - makes California's climate cooler in areas * Deep Currents - caused by temperature and salinity/density *Upwelling - process in which cold nutrient-rich water from the deep ocean rises to the surface and replaces warm surface water WAVES – move in circular motion – caused by wind TIDES - caused by gravitational pull of the moon Tsunami – Giant wave that forms after a volcanic eruption, submarine earthquake, or landslide Storm Surge – a local rise in sea level near the shore that is caused by strong winds from a storm, such as a hurricane EL NINO - change in the water temperature in the Pacific Ocean that produces a warm current * causes - flooding on the west coast and drought in the southeast US LA NINA - change in the eastern Pacific Ocean in which the surface water temperature becomes unusually cool * causes - drought on West coast and flooding in southeast US Unit 4 WEATHER AND CLIMATE ATMOSPHERE – mixture of gases that surrounds a planet or moon 78 % nitrogen 21% oxygen 1% other gases Four Layers Troposphere – lowest layer of atmosphere, in which temperature decreases at a constant rate as altitude Stratosphere – layer of the atmosphere that is above the troposphere and in which temperature increases as altitude increases Mesosphere – layer of the atmosphere between the stratosphere and the thermosphere and in which temperature decreases as altitude increases Thermosphere – uppermost layer of the atmosphere, in which temperature increases as altitude increases HOW THE SUN’S ENERGY IS TRANSFERRED IN THE EARTH’S ATMOSPHERE Radiation – energy transferred from the sun as electromagnetic waves – ex. Walk outside on a hot day – feel the sun’s warmth on your face Thermal conduction – thermal energy transferred through a material – ex. You hold a cup of hot chocolate and it warms your hands – pan on stove heats up because it touches the burner Convection – thermal energy transferred by the circulation/movement of a liquid or gas – ex. Boiling water w/food coloring in it – the food coloring moves in a circular motion GREEN HOUSE EFFECT – the warming of the surface and lower atmosphere of carbon dioxide, and other gases absorb and reradiate thermal energy – the sun’s energy is trapped in the Earth’s atmosphere and cannot escape, so, therefore the surface of the continues to heat up. GLOBAL WARMING – a gradual increase in average global temperature WIND – the movement of air caused by differences in air pressure/differences in temperature Global winds – combination of convection cells found at every 30° latitude and the Coriolis effect produces patterns of air circulation o Polar Easterlies – prevailing winds that blow from east to west between 60° and 90° latitude in both hemispheres o Westerlies – prevailing winds that blow from west to east between 30° and 60° latitude in both hemispheres –prevailing winds for the United States o Trade winds – prevailing winds that blow northeast from 30° north latitude to the equator and that blow southeast from 30° south latitude to the equator o Doldrums – the area where the trade winds meet at or near the equator and there is very little wind, because of very warm air rising creates a very low pressure area o Horse latitudes - 30° north and 30° south, sinking air creates a high pressure area, winds in these areas are very weak – most of the world’s deserts are located in the horse latitudes because the sinking air is very dry Local winds – o Jet streams – narrow belts of high speed, strong winds that blow in the upper troposphere- do not follow regular paths – North America has a jet stream that affects our weather and flight paths o Mountain Breezes/Valley Breezes – day – warm air flows up the mountain side night – cool air moves down the mountain slopes o Sea Breezes/Land Breezes – day – land heats up air and air from the sea blows to land night – land cools and air from land blow to the sea AIR POLLUTION – the contamination of the atmosphere by the introduction of pollutants from human and natural sources Primary pollutants – pollutants put directly into the air –ex. Dust, volcanic gases, ash , smoke from fires, and pollen Secondary pollutants – pollutants that react when mixed with other primary pollutants – ex. Smog, acid precipitation Ozone – the protective layer in the atmosphere that protects the Earth from most of the Sun’s most harmful UV Rays Has holes at present and is still thinning Causes – CFC’s – in aerosol cans – legislation is protecting the ozone now.