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Exam 2
Natural Hazards, Volcanos
77
Geology
Undergraduate 1
03/15/2009

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Cards

Term
which of the following is not a natural hazard?
Definition
volcano, earthquake, hurricane, tsunami, mudslide
Term
How does a catastrophe differ from a disaster?
Definition
A catastrophe requires a long recovery time while a natural disaster is not one unless there is population density, land use, magnitude & frequency
Term
Why is history important in understanding natural hazards?
Definition
It helps predict the the next eruption or disaster by following a pattern.
Term
Why are precursor events important?
Definition
help with evacuation/saving lives
Term
To what does the concept of acceptable risk refer?
Definition
risk society willing to endure
Term
why does population increase affect the number of catastrophic events?
Definition
thicker the population density and land use among other things increases the severity of what might be considered a disaster
Term
Which of the following natural hazards is not likely to occur in Michigan?
Definition
tsunami, hurricane, earthquake, volcano, tornado
Term
How does earthquake magnitude differ from intensity?
Definition
magnitude refers to the quantitative and the intensity refers to the qualitative.
Term
The 1811-1812 New Madrid earthquakes were different from most California earthquakes because...
Definition
It was an intraplate earthquake rather than an interplate EQ/much stronger than interplate/ rocks stronger in Eastern US
Term
A strike-slip fault has what type of motion?
Definition
right lateral vs. left lateral
Term
Surface waves are produced by...
Definition
seismic activity, volcano? earthquake?
Term
During the strain accumulation phase of the earthquake cycle...
Definition
pressure builds up
Term
Why might the emission of radon gas be useful in predicting earthquakes?
Definition
radon gas is emitted from rocks electrical currents while the pressure builds before the actual earthquake
Term
Which of the following is not a likely effect of an earthquake?
Definition
shaking, ground rupture, liquefaction (saturated sediment becomes liquid), landslides, fires, diseases, tsunamis, land topography
Term
Why is ravine erosion a problem at Grand Valley State University?
Definition
Because the foundations of the buildings could be affected
Term
Viscosity of magma is controlled by what?
Definition
temperature
Term
Why do composite volcanoes consist of alternating lava and pyroclastic layers?
Definition
The lava flows then the ash falls on top of that layer and then is covered by more lave and so on
Term
The shape of shield volcanoes is a function of
Definition
many lava flows, low viscosity
Term
Mid-ocean ridge volcanism produces what type of volcanic rock?
Definition
basalt
Term
Composite cones typically are associated with what type of plate tectonic feature?
Definition
subduction
Term
What is the principal difference between craters and calderas?
Definition
crater is a depression at top of volcano only a few km's a caldera is 20 or more km's
Term
Why were the citizens of Heimaey, Iceland, successful in stopping the lava flow that threatened their harbor?
Definition
hydraulic chilling
Term
What is one reason that ash fall is such a significant hazard?
Definition
can destroy crops and land use for years
Term
Hundreds of residents near a dormant volcano at Lake Nyos died when
Definition
CO2 released into the air
Term
The number of fatalities from the Mt. Pinatubo eruption was relatively low because
Definition
much effort made to evacuate when volcanic activity warned officials
Term
Seismic activity serves as a tool of volcanic forecasting because
Definition
molten lava rising to the crust creates earthquakes through disruption of the rocks before the actual eruption
Term
Why is the geologic history of a volcano important in hazard prediction?
Definition
because volcano's erupt every X years give or take a couple thousand years
Term
Why is topographic monitoring sometimes useful in forecasting a volcanic eruption?
Definition
The seismic activity created by volcanic activity can sometimes cause the topography to shift
Term
The portion of rainfall that flows off the land and directly into a river is called...
Definition
runoff
Term
What is river base level?
Definition
the lowest point which a river can erode to...usually being sea level
Term
The suspended load of most rivers consists mostly of...
Definition
sediment carried above streambed
Term
If a stream channel is of constant width and depth, how must increased discharge be accommodated?
Definition
bigger floodplain
Term
The total load of sediment that a river carries in a given period of time is called
Definition
Total Load/Discharge Rate?
Term
Which type of seismic wave has the highest amplitude?
Definition
Surface Waves (R-Waves)
Term
Material Amplification refers to...
Definition
seismic shaking amplified through soft sediments such as clay and silt
Term
WAVE FORMULA
Definition
Velocity = Wavelength * Frequency
Term
A caldera eruption would likely be _________ times greater than the eruption of Mount Saint Helens in 1980.
Definition
1,000 times more
Term
Which of the following is not considered a primary effect of a volcanic eruption?
Definition
Term
Which of the following is not considered a primary effect of a volcanic eruption?
Definition
Primary Effects are effects that are a direct result of the volcano
Term
Where is the world’s largest active landslide?
Definition
Hawaii
Term
The eruption of Mount Saint Helens began with a(n)
Definition
a horizontal blast blowing off a chunk of the side of teh volcano
Term
Which of the following is the best solution to the ravine problem?
Definition
riprap/helicoptering in rocks
Term
Which of the following rock types would be considered mafic?
Definition
basalt
Term
What was the magnitude of the earthquake that caused the 2004 Indonesian Tsunami?
Definition
9.0
Term
What caused the majority of deaths in the case history of Nevado del Ruiz?
Definition
hazard maps were circulated but not explained correctly
Term
The difference between an upstream and a downstream flood is . . . ?
Definition
upstream flood is caused by intense rainfall in the upper drainage basic while downstream is caused because of longer storming that saturates the soil
Term
What is the difference between a reactive and anticipatory response?
Definition
anticipatory response is a result of information obtained prior to an event while reactive response is a response to an event already happening
Term
Why might global climate change impact the magnitude and frequency of hazardous events?
Definition
because the temperature and pressure of the global climate greatly affects the magnitude and frequency of hazardous events
Term
Why might global warming increase the magnitude and/or frequency of weather-related hazards?
Definition
An increase in the average temp. of the global climate would lead to higher frequency
Term
Mercalli intensity values assigned to locations how?
Definition
based on observers
Term
Why might global warming increase the magnitude and/or frequency of weather-related hazards?
Definition
An increase in the average temp. of the global climate would lead to higher frequency
Term
How can injection of liquid wastes cause earthquakes?
Definition
creates stress by altering the underlying rocks
Term
Why have 20th Century earthquakes in Turkey suggested that some earthquakes beget subsequent earthquakes?
Definition
Term
An active fault is defined as a fault that..
Definition
Still displays seismic activity
Term
Why did the 1976 Tanshan earthquake in China deal a blow to the Chinese earthquake prediction program?
Definition
Term
The deadly 1985 eruption of Nevado del Ruiz is an example of inaccurate prediction.
Definition
False
Term
Volcanic eruptions are one of the few natural hazards that have no benefit to humans.
Definition
False
Term
The focus is the point at depth where the rocks ruptured to produce the earthquake.
Definition
False
Term
An earthquake with a deep focus is more destructive than an earthquake with a shallow focus.
Definition
False
Term
Mudslides may be caused by plate tectonics or atmospheric disturbance.
Definition
True
Term
Viscosity is a primary control on the nature of volcanic activity.
Definition
True
Term
Hot lava typically flows faster than cold lava of similar composition
Definition
True
Term
A shield volcano is typically andesitic in composition.
Definition
True
Term
Bubbles stay preserved the longest in the lava with the lowest viscosity.
Definition
False
Term
Lava with high solid content flows faster than lava with low solid content.
Definition
False
Term
Lava flows are the most dangerous of the primary volcanic hazards.
Definition
False
Term
The 1980 eruption of Mt. St. Helens produced large lava flows that filled the nearby river valleys.
Definition
True
Term
Base Level of a stream is typically sea level
Definition
True
Term
There was no secondary prevention for flooding in the New Orleans, Hurricane Katrina case history.
Definition
True
Term
The November 2002 earthquake that occurred in Alaska was classified as a disaster due to a rupture of the oil pipeline.
Definition
False
Term
Levees constructed on the Mississippi River provided a false sense of security to landowners along its banks.
Definition
False
Term
A catastrophe is an event that requires a long recovery period.
Definition
True
Term
Most natural hazards are non-repetitive events.
Definition
False
Term
The epicenter of an earthquake is the point of rupture along the fault.
Definition
True
Term
Depth of focus is an important factor in determining the intensity.
Definition
True
Term
Most large earthquakes in the U.S. are interplate earthquakes.
Definition
False
Term
The magnitude of an earthquake is a function of its location.
Definition
True
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