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Diagram and explain the rock cycle
- igneous rocks from when lava or magma cools and hardens
- sedimentary rocks from from sediment
- - clastic = formed when broken pieces of other rocks are compacted and cemented
- - organic = form from remains of plants and animals
- - chemical = form when dissolved minerals come out of solution
- metamorphic - any rocks changed by heat and pressure
- - foliated = have grains arranged into bands or layers
- - nonfoliated = do not show banding
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Describe relative and absolute dating techniques, including how half-lives are used in radiometric dating
- relative age:
- age when compared with the ages of other rocks, layers of sedimentary rock, law of superposition - in layers of horizontal sedimentary rock, the oldest layer is at the bottom
- igenous intrusions (hardened magma that was pushed up from the mantle, look younger), faults (break in the Earth's crust) and other gaps in time
- inclusions - pieces of rock that are made part of a newly forming rock
- uncomformities - gaps in time
- match up layers across a big area - aided with index fossils (widespread, from an organism that did not exist for long)
- absolute age:
- a calculation of the number of years that have passed since the rock formed
- radioactive elements - unstable elements
- rate of decay of a radioactive element is constant
- half-life = the length of time it takes for half of the radioactive atoms in an element to decay into a different atom
- the age of a rock is determined using radioactive dating
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Compare uniformitarianism and catastrophism
- catastrophism: the idea that a series of sudden and widespread catastrophes created the features on Earth
- the six catastrophes would have caused rapid and significant changes on Earth, corresponding to the Bible
- not a valid hypothesis - no evidence
- uniformitarianism: history of Earth is cyclical in nature
- plutonism - igenous rocks came from cooling magmas
- unconformity - a gap in time, indicating time of erosion in the rock record
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Describe the dynamic processes of erosion, deposition, and transport
- erosion:
- particles that have been made small enough are removed by erosion, altering the shape of landforms
- water running downhill is the dominant agent
- transport:
- after material is picked up by erosion it is transported
- deposition:
- material that is transported is eventually deposited
- when transporting agent slows and no longer as the energy to carry the material
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Describe coastal processes including beach erosion and natural hazards
- coastal processes - battle between land-dominated processes and ocean-dominated processes
- delta - deposition of sediment by rivers
- dunes - wind may deposit sand along a shoreline
- beaches - sand and larger sediments often remain at the shore
- barrier islands - longshore current may pick up sand and carry it along the shoreline and forms barrier islands when the sand is deposited
- beach erosion - waves may undercut a bank, causing a landslide
- hurricanes - these storms form in the tropics where the ocean surface is warm
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Describe the effects of natural hazards, including earthquakes, volcanic eruptions, landslides, and floods, on natural and human-made habitats and environmental and human responses to those events
- earthquakes:
- the natural environment recovers quickly
- in human environments buildings collapse, gas pipes rupture, can trigger a landslide
- locations for schools and hospitals should be found by looking at geologic maps
- structures should be built to be able to withstand some ground shaking
- tsunamis:
- enormous waves triggered by undersea earthquakes or volcanic eruptions
- damage to the environment can be high - saltwater infiltrates aquifers and farmland
- volcanic eruptions:
- can destroy natural and human habitats near the volcano or at a great distance
- explosive eruptions can cause the most damage by spewing ash and rock over large areas - reducing air quality, causing acid rain
- predicting - give signs such as increased earthquake activity, gas emission, ground deformation, higher heat flow
- landslides:
- when soil and rock move rapidly down a hillside
- cause damage to whatever they drag downhill
- flood:
- when there is too much rainfall or snowmelt for existing drainages
- can bury or wash away habitats
- controlling methods - planting vegetation, digging channels, levees, dams
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