UofM Earth 108 - Earthquake/Water Cards
Natural And Physical Sciences Earth 108 002 with Ruff at University of Michigan - Ann Arbor
About this deck
By: Bill Hass
Created: 2012-04-15
Size: 71 flashcards
Views: 702
Created: 2012-04-15
Size: 71 flashcards
Views: 702
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Definition of an earthquake
Rapid shear slip across a fault surface.
What are the 3 slip directions?
Strike Slip [horizontal/cross motion]; Normal fault [top layer moves down]; Reverse fault [top layer moves up]
San Andreas is what type of fault?
Strike-slip fault.
Magnitude 5-6 slips how far?
Less than 1 meter
Magnitude 7-8 slips how far?
Approx. 1 to 3 meters
Fault Scarp is?
The face of a normal fault
T/F Finding thrust faults is straightforward; look for the rock thrusting out of the crust.
False. Many thrust faults form "blind" faults where the thrusted rock crumbles under its own weight and forms a mound.
What is creep?
When faults slip slowly.
T/F Rapid slip across a fault results in earthquakes.
True. It must be rapid.
A P wave is a compressional, shear or surface wave?
Compressional
An S wave is a compressional, shear or surface wave?
Shear
T/F Earthquakes exhibit a combination of p-waves, s-waves, and surface waves.
True.
Note position of : Epicenter, Focus, Fault, Surface Rupture.
What are the 3 hazards of earthquakes?
Buildings falling; Landslides; Tsunamis
T/F Massive earthquakes [Magnitude 8+] can have accelerations exceeding 1g.
False. Max acceleration of earthquakes is about 1g
Where do most earthquakes occur?
Most occur at plate boundaries, more specifically: subduction zones.
The deeper they occur, the further from fault line and further from surface rupture the epicenter is.
If the earthquake occurs ON the plate boundary, it is: [shallow, midway, deep]
Shallow
If the earthquake occurs in the lithosphere, it is: [shallow, midway, deep]
Deep
Why do earthquakes occur across a broad range near plate boundaries?
Because of the differing depths of the earthquakes
Modern way to measure earthquakes?
Magnitude system
How does magnitude system work?
log10(maxAmplitude) at a standard epicentral distance
The old fashioned way to measure earthquakes?
Intensity
How frequent do magnitude 8 EQs occur?
once a year
How frequent to Magnitude 7 EQs occur?
once a month
As magnitude decreases, how does the frequency of occurrences change?
Frequency of occurrences increases by factor of 10 as magnitude decreases by 1
If the threshold of a given EQ map is 3, what is the average magnitude of the earthquakes shown?
avg. magnitude would be 3.
If the threshold of a given EQ map is 7, what is the average magnitude of the earthquakes shown?
avg. magnitude would be 7.
At what intensity are there economical consequences?
Intensity 5
Isoseismal maps are maps of what?
Maps of intensity
At approximately what magnitude does intensity reach 5?
About magnitude 5 is a good approximation to intensity 5.
Why was the Haiti EQ so deadly?
Because their poorly constructed buildings collapsed easily
T/F The Haiti EQ had typical intensity for the magnitude of the EQ that occurred.
True. Intensity was not unusually high for the size of the EQ.
Why do our structures fail? [2 reasons]
1. The soil beneath them fails. 2. The structure members fail
Two types of soil failure are?
Landslides and liquefaction
T/F The San Francisco Bay Area was protected from damage by the Loma Prieta EQ because its soft sediments dampened the shaking
False. Soft and/or water saturated soil amplifies the violent shaking
Structures fail in which direction? [horizontal or vertical]
Horizontal
T/F Heavy roof and brick walls are good buildings to be in during earthquakes.
False. Heavy roofs have a lot of inertia and fall easily; brick walls are brittle and crumble.
Three things you can do to make a good, EQ proof structure are?
Use shear bracing; Use wood/steel/tough materials that won't crumble; Use strong joints between roof, wall, foundation
What are the 3 best materials for EQ proof buildings?
Wood; Steel; Reinforced concrete
How much water do we need as biological creatures per day?
2 to 3 liters
What is the average US water use per person per day?
Just under 600 liters
T/F The average water usage per person per day is pretty even across the globe.
False. It varies wildly depending on country.
What are the top two areas of water consumption in the modern age?
1. Irrigation for agriculture
2. Thermoelectric power
Along with temperature, what is the most important variable for climate?
Precipitation [hot/wet = jungle versus hot/dry = desert]
About how much of Earth's water is fresh water?
3% the rest (97%) is saline
T/F Earth's fresh water mostly resides in great surface bodies and rivers such as the great lakes and Nile.
False. 68% is in galciers and 30% is in the ground
What percentage of Earth's fresh water is surface water?
0.3 % (yes that's less than a third of a percent)
T/F Of the fresh surface water, a little under 90% is contained in lakes.
True. 87% to be exact.
What is a Hadley Cell and where are they located?
Circulation of air (warm/moist rising, cool/dry falling) between +30 degrees latitude, the equator, and -30 degrees latitiude
Purple regions correlate to deserts; Most rainfall occurs over the ocean and along the equator.
T/F The US follows the global trends for rainfall.
False. The US has a vertical split instead of horizontal bands of rainfall.
From East to West, how does annual precipitation trend in the US?
East = Most rainfall West = Least rainfall
What are the three biomes focused on in class for the US? What are their avg. annual rainfalls?
1. Forest [30-35 in/yr]
2. Grassland [20-25 in/yr]
3. Desert [<5 in/yr]
2. Grassland [20-25 in/yr]
3. Desert [<5 in/yr]
What helps us identify hi-yield agriculture potential?
Terrestrial Biomes
1. US, Europe, and China are hot spots for grain production.
2. Those same continents also have temperate deciduous forests in those hot areas (not a coincidence)
2. Those same continents also have temperate deciduous forests in those hot areas (not a coincidence)
This burst characteristic leads to flood events
What are two means of natural flood control?
1. Ground infiltration
2. River floodplanes
2. River floodplanes
T/F After a rain event, water quickly gushes out of the main river outlet.
False. There is a time delay due to tributaries and ground seepage
T/F Floods are good.
True. Natural is good according to Ruff
T/F River flow is just as "spiky" as precipitation.
False. It is less spiky but still highly variable
What are two good uses for flood planes? What are two bad uses?
Good: Farming [great soil] and parks [if you can afford to not grow food]
Bad: Permanent structures and suburbs/cities/places where people live
Bad: Permanent structures and suburbs/cities/places where people live
What is one way to prevent flood damage?
Don't build in flood planes.
What is the tradeoff in building a dam in terms of flood hazards?
Small flood hazards are stopped, but large flood hazards are greatly magnified.
What is the hazard of a natural river system?
None because it's a natural occurrence we're too stupid to avoid.
The 1993 flood occurred on what river? Why was it so bad?
The Mississippi flooded and caused great damage to agriculture and cities across midwest
Concrete, pavement, and buildings don't allow water to seep into the ground. Levees force water places it shouldn't be naturally
Name 3 things humans build that directly increase flood hazards.
artificial levees, river channelization, dams
T/F Longer the time delay between rainfall and river flow, the smaller the flood.
True. This is why urbanization is so bad, shortens time delay thus increasing impulse volume of water
How should we mitigate flood hazards?
Land use planning, and enforcement/incentives so that we don’t build permanent structures in floodplain.
Does the US do a good job of flood mitigation?
No! The US subsidizes & compensates people to live in flood planes! STUPID IGNORANT AMERICANS!!!
About this deck
By: Bill Hass
Created: 2012-04-15
Size: 71 flashcards
Views: 702
Created: 2012-04-15
Size: 71 flashcards
Views: 702
About StudyBlue
STUDYBLUE makes things that make you better at school.
Things like online flashcards with photos and audio.
Things like personalized quizzes and friendly reminders about when (and what) to study next.
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“I have been getting MUCH better grades on all my tests for school. Flash cards, notes, and quizzes are great on here. Thanks!”
Kathy
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