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Download Seismology and Earthquakes: Terms and Concepts and more Quizzes Geology in PDF only on Docsity!
Seismicity
The release of energy within the earth's lithosphere due to
movement on a fault or production of a new fault.
TERM 2
2 Types of Stress
DEFINITION 2
Compressional - Push together Tensional - Pull apart
TERM 3
Strain
DEFINITION 3
A material's response to an applied force (stress).
TERM 4
Elastic Behavior
DEFINITION 4
Deforms when stress is applied, then snaps back to its
original shape.
TERM 5
Brittle
Failure
DEFINITION 5
Lithosphere Will break if too much stress is applied.
Plastic Behavior
Deforms when stress is applied and stays that way when the
stress is removed. Flows.
TERM 7
Elastic Rebound
DEFINITION 7
An earthquake, and the release of built up strain in rocks
(energy release).
TERM 8
Creep
DEFINITION 8
Strains are regularly released resulting in no major
earthquakes.
TERM 9
Focus
DEFINITION 9
Place along the fault where movement is initiated or first
occurs.
TERM 10
Epicenter
DEFINITION 10
The point on the Earth's surface that is directly above the
focus, and where an earthquake originates.
Shear Waves
Move slowly in a side to side direction through solids ONLY.
TERM 17
2 Types of Surface Waves
DEFINITION 17
Travel along earth's surface. Love waves. Raleigh waves.
TERM 18
Which type of waves are worse?
DEFINITION 18
Surface waves. Raleigh and Love
TERM 19
S-Wave Shadow Zone
DEFINITION 19
Area the s-waves can't reach due to the liquid outer core.
TERM 20
Where were the 2 worst earthquakes?
DEFINITION 20
Missouri and South Carolina Inner plate earthquakes.
What are the 3 main seismic hazard regions
in the U.S.
West-Coast Mid-Continent Charleston
TERM 22
Richter Scale
DEFINITION 22
Measures the amount of absolute ground motion. (1-9).
Logarithmic scale.
TERM 23
How does the Richter Scale work?
DEFINITION 23
When we move up 1 unit, the amount of absolute ground
motion inc 10x. From 1 to 4 = 10 x 10 x 10
TERM 24
Mercalli Index
DEFINITION 24
Human response to earthquakes. I-XII
TERM 25
5 Ways to Reduce Ground Motion
DEFINITION 25
Don't build on known faults Don't rebuild on faults (Istanbul)
Don't built anything you want thrown in the air; nuclear
power plants Follow building codes (Haiti) Utilities building
codes (gas valve shut offs)
Precusor Phenomena
Uplift/Tilting Water-Well Levels Electrical Properties Cyclicity
Animal Behavior
TERM 32
3 Ways to Generate Magma
DEFINITION 32
Subduction Rifting Hot Spots
TERM 33
Subduction
DEFINITION 33
At a certain depth water is released and melting occurs,
creating a volcanic arc.
TERM 34
Rifting
DEFINITION 34
Mantle upwelling zones will produce these on oceanic and
continental crusts.
TERM 35
Hot Spots
DEFINITION 35
Fixed in the mantle. Lithospheric plates above are in motion.
Silica Polmerization
Si chains together.
TERM 37
Felsic Magma
DEFINITION 37
Lots of Silicon. - Viscous Undegassed, resulting in an
explosion. Magma is very think, which is the reason the gas
bubbles can't escape.
TERM 38
Viscosity
DEFINITION 38
How easily something flows. The more Si the more viscous.
TERM 39
Mafic Magma
DEFINITION 39
Fe rich Watery Degassed near surface Thin magma Less
viscous
TERM 40
2 Types of Eruptions
DEFINITION 40
Fissure Point-Source
Pyroclastic Material
What is ejected into the air in a Rhyolite pt-source eruption
after solidified.
TERM 47
2 Dome Volcanoes
DEFINITION 47
Cinder Cones and Composite or Strata Volcanoes
TERM 48
What does a composite volcano eject?
DEFINITION 48
Basaltic lava and more felsic pyroclasts.
TERM 49
Composite Volcano Examples
DEFINITION 49
Cascade Range, Mt. Fuji, AK Range, Andes Occur anywhere
there is a subduction zone.
TERM 50
Volcano Sizes
DEFINITION 50
Shields are long in length Composite is tallest, Mt. Shasti Cali
Cinder is smallest, Arizona
Caldera
Most dangerous of all. Yellowstone
TERM 52
5 Volcano Hazards
DEFINITION 52
Lava Pyroclasts Pyroclastic Flows Lahars Gas, Aerosoles,
Steam
TERM 53
4 Ways to Predict
DEFINITION 53
Seismicity - weak/shallow Tilting/Bulging Gasses Animals
TERM 54
4 U.S. Hazard
Areas
DEFINITION 54
Cascades, Alaska, Hawaii, Hot Spots
TERM 55
Cascades and Alaskan Eruptions
DEFINITION 55
Explosive
4 Components of Stream Size
Drainage basin size Vegetation Climate Bedrock composition
TERM 62
Discharge
DEFINITION 62
Volume of water that flows past a given point in some
amount of time.
TERM 63
Discharge Formula
DEFINITION 63
Q(Discharge)=Sectional Area + Velocity
TERM 64
4 Parts to Total Sediment
Load
DEFINITION 64
Bedload Saltation load Suspended load Dissolved load
TERM 65
Bedload
DEFINITION 65
Sediment rolling along the bottom.
Saltation Load
Sediment "bouncing" along the bottom.
TERM 67
Suspended Load
DEFINITION 67
Sediment not touching the bottom.
TERM 68
Dissolved Load
DEFINITION 68
Stuff in solution.
TERM 69
Capacity
DEFINITION 69
Measure of the total load a stream can carry.
TERM 70
Competance
DEFINITION 70
A measure of the largest particle a stream can move.
Infiltration
Soak into the ground.
TERM 77
Evapotranspire
DEFINITION 77
Water is taken by a plant and then back to the atmosphere.
TERM 78
Flood Magnitude
DEFINITION 78
Whether an area floods.
TERM 79
Flood Magnitude Factors
DEFINITION 79
Amount of precipitation Rate of runoff and infiltration
TERM 80
Infiltration & Runoff
Factors
DEFINITION 80
Soil Type Topography (flat, steep) Vegetation
Flood Stage
Elevation of water in stream at point it goes over levee into
the floodplain.
TERM 82
Flood Crest
DEFINITION 82
Highest elevation of the water during a flood event.
TERM 83
2 Flood Types
DEFINITION 83
Upstream Downstream
TERM 84
Upstream Flood
DEFINITION 84
Flood a single tributary and mainstream system is open
causing the flood to go up and down quickly. Caused by
sudden impacts.
TERM 85
Downstream Floods
DEFINITION 85
Entire system is full and takes months to subside.
Local/Regional Flood Control Example
Levee's Mississipi river
TERM 92
Channelization
DEFINITION 92
Straighten rivers to allow for more drainage.
TERM 93
Channelization
Cons
DEFINITION 93
VERY expensive b/c if it meanders at all you have to
restraighten it. Negative biological impact.
TERM 94
Dam Examples
DEFINITION 94
Glen Canyon. Hoover. 3 Gorges.
TERM 95
Dam Impacts
DEFINITION 95
Generate lots of power/electricity without burning anything.
Fundamentally change the environment they are put in.
(Beauty). Floodplains downstream starve and the fish can't
get through.
Volcanic Hazard
Areas
Cascades, Alaska, Hawaii
TERM 97
Cascades
DEFINITION 97
Subduction
TERM 98
Alaska
DEFINITION 98
Subduction
TERM 99
Hawaii
DEFINITION 99
Hot spots
TERM 100
Yampa
River
DEFINITION 100
In Colorado, THe only river without a dam.
