Earth science Notes.pdf

Earth Science notes Geosphere: the layer of Earth made up of solid rock and other rocky materials. Hydrosphere: the total amount of water on a planet. Atmosphere: a mixture of gases that surrounds the Earth. Biosphere: the region of the earth that encompasses all living organisms: plants, animals...

Earth Science notes Geosphere: the layer of Earth made up of solid rock and other rocky materials. Hydrosphere: the total amount of water on a planet. Atmosphere: a mixture of gases that surrounds the Earth. Biosphere: the region of the earth that encompasses all living organisms: plants, animals and bacteria. Lithosphere: the solid, outer part of Earth. Earth resources P waves Primary waves Higher speeds First to arrive at seismogram Travels through all elements S waves Secondary waves Difference in arrival times between p and s waves can be used to determine the distance to the location of the fault Travel through only solids Silca: a hard, unreactive, colourless compound which occurs as the mineral quartz and as a principal constituent of sandstone and other rocks. Silicate: a salt or ester derived from a silicic acid. Non Silicate: minerals that do not include the silicon-oxygen units characteristic of silicates - felsic minerals (igneous rocks that are relatively rich in elements that form feldspar and quartz) - Mafic minerals (minerals that are rich in iron and magnesium and rocks that are rich in those minerals) Felsic: felsic means the lava or rock contains the most silica. Mafic: mafic means the lava or rock contains less silica. Properties used to identify materials Composition Cleavage planes Fracture Mohs Scale Colour Lustre: Appearance of light reflected off a mineral surface, Some do not reflect light and are described as dull or earthy Feature Streak:Dragging across a tile leaves a streak Igneous: form when hot, molten rock crystallizes and solidifies. Eg obsidian, pumice Sedimentary:sediment is buried deeply, it becomes compacted and cemented, forming sedimentary rock. eg sandstone, limestone, Metamorphic:formed by high heat and high pressure. eg quartzite, marble Relative Dating; use to determine the approximate age of a structure based on its physical relationship to surrounding geologic structures.eg law of superstition Absolute dating;measure the physical properties of an object itself and use these measurements to calculate its age. Eg radiocarbon dating Layers of Soil: Organic, top soil, subsoil, parent material, bedrock, Preventing Soil Erosion; - Stock rotation - Control of pest animals - French high risk areas like hills - Pave water channels - Tree planting ( roots hold soil together) - Geological Time Scale Rock Cycle Law of Superpostion Plate tectonics Alfred Wegener Theroy: Continental drift theroy, fit like a jigsaw 7 large plates, 10 minor plates, 15 small plates Divergent: Move away from each other Convergent: Collide into each other Transform: Sliding past against each other Normal: a dip-slip fault in which the block above the fault has moved downward relative to the block below. Ocean- Ocean Continent- Contienet Ocean-Contient Contractionists: Cooling and shrinking was constant throughout time Permanentists: Rapid cooling early in earths history. Sea-floor spreading: the usual process at work at divergent plate boundaries, leading to the creation of new ocean floor. rift valley: a lowland region that forms where Earth's tectonic plates move apart, or rift. mid-ocean ridge; formed where two tectonic plates meet under the ocean. Trench: long, narrow depressions on the seafloor that form at the boundary of tectonic plates where one plate is pushed under another. Fault: One plate goes down under another Reverse fault: one in which one side of the fault, the hanging wall, moves up and over the other side, the foot wall. Subduction: the process that occurs when two tectonic plates meet at convergent boundaries, and one of the plates moves under the other one due to gravity and differences in density fossil fuels: non-renewable energy sources such as coal. originate from plants and animals that existed millions of years ago Mineral = non organic naturally occurring material with a distinctive colour Energy Tranformations Convection Currents: movements of fluid caused by a temperature or density difference within a material. occur in the air, ocean, and mantle. Thermohaline Circulation: the movement of ocean currents due to differences in temperature and salinity in different regions of water. Ekman flow: When surface water molecules move by the force of the wind, they, in turn, drag deeper layers of water molecules below them. Downwelling: the water on the surface of the sea becomes denser than the water beneath it and so it sinks. Less dense goes up transformed : changed one to another Transfered: move from one place to another Sun is primary source of energy Surface tension: Is the resistance of a fluid to change in its surface area Radiation: transfer of energy by electromagnetic waves Conduction: is the way energy is transferred through contact. Convection: when material flows from one area to another due to density differences Gravity and heat create convection and the motion of lithospheric plates Evaporation: liquid to gas through the sun Preciptation: any liquid or frozen water that forms in the atmosphere and falls back to the earth. Transpiration: the evaporation of water from plants, especially leaves. Advection: horizontal movement of a mass of fluid Solvent properties: A substance that can dissolve other substances. A living cell contains a large variety of molecules dissolved in water. Troposphere: the layer closet to earths surface and this where weather and climate occur. Radioactive decay: is the emission of energy in the form of ionizing radiation. El Nino La nina Human impacts Storm water: rainwater that falls on sealed surfaces and carries anything. Eg pollutants Ground water: water that exists underground in saturated zones beneath the land surface Formation of Soil: Urban salinity: The redistribution of salts, and the impact these salts have on our urban environment. Dryland salinity: taking out of long rooted plants and plating of new short rooted plants affecting the water cycle as less nutrients are being soaked up Irrigation Salinty; increase of water making the water cycle to increase making salt rise to the water. Preventing soil eroiosn: replanting with vegetation and deep rooted plants. In urban areas steep slopes and stormwater ditches. Preventing Soil Erosion; - Stock rotation - Control of pest animals - French high risk areas like hills - Pave water channels - Tree planting ( roots hold soil together) Managing dryland Salinty - Lucerne - Restoring vegetation,( deep rooted) - Cropping systems that incorporate perennial vegetation Managing Irrigation Salinity - Irrigation monitoring technology minimise water use. - Automated irrigation systems can monitor soil levels Managing Urban Salinity - Leaking stormwater channel replacement - Septic tanks Lead is the largest soil contaminet Osmosis: movemnt of water molicules Invasive species: animals or plants from another region of the world that don't belong in their new environment. eg carp, rabbit 1. High reproductice success 2. Successfful disperal over a large range 3. Few or no natural predatores or disease 4. Able to use a variety of habitats 5. High cost to remove - Damage to vegetation - Competion for space,food, land degradition - Economic impact Viruses are used to kill off, but genes modif to virus. EG: - Carp eat mud increasing soil ersoion - Turning up water decreases the sunlight reaching plants, lowering oxygen levels - Eat eggs of other fish - Poor visbiliaty - Prickly pear brought in as a pot plant, gave to his neighbours - Cover 24 million hectares of Australia - Conditions are ideal, seeds spread by birds - Infestation of pasture crops - Introduce new insects to kill of plant Introduced species: those that have been moved by humans to an environment where they didn't occur naturally normal to solve a problem in an ecosystem. Eg beetles Abiotic: not living Biotic: living or once lived Terrestial ecosystems: Ecosystems are those on land Aquatic: Ecosystems are those in water Indian Ocean Dipole: An irregular change in sea surface temperature between the western and eastern sides of the indian ocean. Madden-julian Oscillation: Influences rainfall patterns in equatorial areas. Northern Australia, slowly moves eastward across the indian and pacific oceans.