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What kinds of faults generate earthquakes?
Normal faults, Reverse, Thrust, and Strike-Slip
In what shape does a fault rupture grow
When are rocks under greatest stress and stored elastic strain
Rocks are under greatest stress during a slip and Earthquake, they return to their unstrained shape during post-slip faulting
Where on Earth do Earthquakes occur
Most earthquakes occur alonge plate boundaries
What happens to arrival times on seismograms at different distances from an earthquake
the delay between the P and S wave depends on the distance. The longer the distance from the earthquake the greater the delay
Difference between the P and S wave movement
- P movement-- the primary wave -- compresses the rock in the same direction it propogates, like a sound wave which compresses the air through the air which it travels. they can travel through solids and liquids because these materials can be compressed and then released. It is the fastest seismic wave.
- S movement-- secondary waves -- shear the rock side to side or up and down perpndicular to the direction of travel. Cannot travel through liquids because they cant be sheared. If Earth doesnt let it pass it may be molten. they are slower.
Maps of Modified Mercalli intensity to interpret earthquake effects and zones
- "I"-"III" reflects barely felt Earthquake
- "XII"-"XI" indicates complete destructionof buildings, with visible surface waves throwing objects into the air. the clower to where the center is the more it was felt, the further, the less its felt.
How are earthquake epicenters and hypocenters determined
- the distance from each station to the earthquake can be plotted as a circle on the map to find the epicenter. Radius is equal to distance from P-S interval.
- Epicenter-- Intersection of three or more circles
- Hypocenter-- is found by using interval between P-wave and another compressional wave that forms when the P-wave reflects off Earths surface near te epicenter
What causes the P and S wave shadow zones
Body waves travel through the fluid layers of the Earth interior, but P-waves are refracted slightly when they pass throught the transition between the semisolid mantle and the liquid outer core. As a result there is a P-wave "shadow zone" in contrast S-waves do not travel through liquids they are attenuated
How do Coriolis winds rotate in different pressure and global positions
- A low pressure system L has a relatively low atmospheric pressure. In the northern hemisphere, winds,andclouds flow counterclockwise around a low-pressure system
- A high pressure system H has a relatively high pressure. In the northern hemisphere, air circulates clockwise around the center, and winds diverge from its center.Southern hemisphere circulation directions are reversed
What is the relationship between atmospheric pressue and altitude
Pressure decreases with altitude
What causes global belts of atmoshperic winds
Sun warms equatoial regions of earth more than poles, setting up a flow of warm air toward the poles, which is balanced by a cold flow of air from the poles toward the equator.
What happens to cause a low pressure system
Low atmospheric pressure- counterclockwise around low pressure system because of Coriolis effect. Areas of pressure lift and cool moist air causes rain and unsettled weather
As temperature increases under constand pressure what happens to water
Raising temperatures caused by sunlight cause the water to evaporate and mix with the air
Rain shadow and the climate change that accompanies it
Rain shadow is when vapor condenses and precipitates on the windward side of a mountain range a dry region. Is formed on the downside of the range forming a desert to the far right.
What causes hurricanes to grow and be sustained
If hurricanes encounters additional warm, evaporating water as it moves, more heat is added, wind increases, and the hurricane grows in strength and size
What states compose "tornado alley"
in the central and eastern parts of the U.S
What is the Gulf Stream
A western boundary current, they are warm, and flow from the equator towards high latitudes and polar regions. Brings waters heated from the tropics to the North atlantic, helping warm the region
What is the Thermohaline conveyor
A deep-water current that takes deep water on a long journey. Is driven by variations in density caused by differences in temp and salinity.
What causes droughts
A persistent weather pattern or change in ocean currents can cause an unusual shift in wind direction. can be caused by weather pattern that are a typical for an area
Explain trough, crest, wave height, wave length, wavebase
- trough- the lowest part of the wave
- crest- highest part of the wave
- wave height- the vertical distance between the two
- wavelength- the horizontal distance between two adjacent crests in a set of waves
- wavebase- wher the wave ceases to have any effect, about half the wavelength
What shoreline features can be used to interpret the movement direction of longshore currents
Current flowing along the coast, a lonshore current, transports sediment parallel to the coast
What is a wave cut platform
continued erosion at sea level can bevel off bedrock forming a flat wave-cut platform. may be covered by water at high tide but fully exposed at low-tide
What causes oceans to be salty
most of the oceans salts are derived from weathering and th dissolution of rocks on the land
What common rock is easily dissolved by water and weak acids
What is the angle of repose
the steepest angle at which a pile of unconsolidated grains remai stable. This angle is controlled by frictional contact between grains
Where in the U.S are you most likely to experience a landslide
highest near steep mountains such as in colorado, the apps, and other mountain areas that have weak, heavily weathered materials
Where is most of Earths fresh water stored
most is in ice and snow or in groundwater below the surface with a smaller amount in lakes, wetlands, and rivers. Glaciers have nearly 69%, groundwater has 30%
is the circulation of water fro one part of this water system to another, is driven by energy from the Sun. beg.- end. Evaporation, condensation, precipitation, sublimation, infiltration, groundwater flow, transpiration, surface runoff.
What kind of sediment likely has the highest porosity
- Porosity is the proportion of the volume of rock that is open space.
- Well rounded and well sorted sediment has higher porosity than angular or poorly sorted sediment because round grains do not fit together as tightly
What kind of sediment has lowest permeability
permeabililty is a measure of the ability of a material to transmit a fluid. Materials with low permeability usually have low porosity. Clay particles such as Shale and similar rocks have very low or perhaps no permeability