Earthquakes- Final Study Guide
True or false: Most of the moment tensors at a divergent plate boundary will be black in the middle.
False
What are the common surface expressions of faults? -Narrow cracks with movement across them -Huge cracks and ravines that you can fall into
Narrow cracks with movement across them
True or false: Most of the major earthquakes that have occurred in California in recent history were expected by seismologists.
false
True or false: Our cities are very resilient to disasters.
false
What kind of fault is the San Andreas faults system? -right-lateral strike-slip fault -left-lateral strike-slip fault -left-lateral transform fault
right-lateral strike-slip fault
What kinds of observations can be explained by plate tectonics (multiple answers)? -Bathymetry of ridges and trenches -Magnetic stripes on the ocean floor -global distribution of earthquakes
-Bathymetry of ridges and trenches -Magnetic stripes on the ocean floor -global distribution of earthquakes
Match the ocean to whether it had an earthquake early warning system in place at the time of the 2004 Sumatra Earthquake. -Pacific Ocean --> -Indian Ocean -->
-Pacific Ocean --> had tsunami early warning system -Indian Ocean --> did not have one, and many could have been saved if it did have one
What are the key features of an induced earthquake? -Spatial correlation -In Oklahoma -Temporal correlation -Shallow -Closeness to gas stations -Greater than magnitude 5
-Spatial correlation -Temporal correlation -Shallow
Which of the following are hotspot tracks? (Select all that apply) -Aleutian Islands -Yellowstone volcanoes -Hawaiian Islands -Cascade Volcanoes
-Yellowstone volcanoes -Hawaiian Islands
What are some causes of man made earthquakes? (Select all that apply) -traffic on freeways -collapsed mine -reservoir filling -oceanic plate subducting under continental plate -wastewater injection
-collapsed mine -reservoir filling -wastewater injection
There are three different types of plate boundaries. Please match them with the correct locations -divergent --> -transform --> -convergent -->
-divergent --> Mid-Atlantic ridge; east African rift -transform --> San Andreas Fault -convergent --> South America and the Himalayas
Choose the correct labels for a and b. (epicenter vs. focus)
-epicenter: on the surface -focus: in the earth
In seismic tomography , seismic stations are used to measured seismic waves and determine their velocities. Match the wave velocity with it's corresponding temperature. -fast velocity --> -slow velocity -->
-fast velocity --> cold temperature -slow velocity --> hot temperature
Which of the following are hazards associated with earthquakes? (Select all that apply). -liquifaction -train derailment -tsunami -slip -shaking -landslides -collapsed buildings
-liquifaction -tsunami -slip -shaking -landslides
The estimated location and magnitude of an earthquake can be determined by the early coming P-wave. What pieces of information we can use for determining them? Please make the correct match. -location --> -magnitude -->
-location --> p-wave arrival times -magnitude --> p-wave amplitude
Please match the plate boundaries with the correct descriptions. -mid-ocean ridges --> -subjection zones --> -transform zones -->
-mid-ocean ridges --> new oceanic plates formed -subjection zones --> oceanic plate destroyed -transform zones --> no plate creation or destruction
Match the waves to the order that they are felt. -p-waves -s-waves -rayleigh and love waves
-p-waves: felt first -s-waves: felt second -rayleigh and love waves: felt third
Which of the following are causes of tsunamis? (Select all that apply) -shallow earthquakes -spontaneous landslides -volcanic eruptions -asteroids -strong lunar tides (i.e. the gravitational pull the moon has on the ocean) -deep earthquakes
-shallow earthquakes -spontaneous landslides -volcanic eruptions -asteroids
Which of the following are hazards associated with earthquakes? (Select all that apply). -improper building codes -slip on fault -shaking
-slip on fault -shaking
Why is the Hayward Fault one of the most hazardous faults in California? (Select all that apply) -so many people live and work on or near the Hayward Fault -large earthquakes frequently occur on the Hayward Fault -the Hayward Fault accommodates 100% of the plate boundary motion -There is a high chance of a big earthquake on the Hayward Fault in the next 30 years
-so many people live and work on or near the Hayward Fault -There is a high chance of a big earthquake on the Hayward Fault in the next 30 years
Which of the following is caused by translational forces and creates movement in the strike direction? -normal faults -reverse faults -strike-slip faults
-strike-slip faults
What do we need to know in order to determine earthquake probability on a fault? (Select all that apply) -the history of earthquakes on the fault -how many people live near the fault -rate of creep on fault -the types of sediments in the area around the fault -How much plate tectonic motion needs to be accomodated by the fault
-the history of earthquakes on the fault -rate of creep on fault -How much plate tectonic motion needs to be accomodated by the fault
The probability of a M>6.7 earthquake occurring on the Hayward fault is approximately [blank]/3.
1
In the next 30 years, what's the chance of an M6.7 or larger earthquake occurring on the Hayward Fault or Rodgers Creek Fault? -1 in 4 -1 in 12 -1 in 3
1 in 3
About every 100-220 years, there will be a large earthquake that occurs on the Hayward fault. When was the last big one? -1906 AD -1868 AD -1695 AD
1868 AD
How many beer keg(s) are equal to one barrel of oil?
2
The probability of a M<6.7 earthquake occurring in the San Francisco Bay Area is [blank]/3.
2
What was the difference between the 2004 Sumatra Earthquake and the 2011 Tohoku Earthquake? -the Sumatra Earthquake was magnitude 9.1, while the Tohoku Earthquake was magnitude 7.5 -many more people were exposed to the Sumatra Earthquake than were exposed to the Tohoku Earthquake -The Sumatra Earthquake was accompanied by tsunamis and the Tohoku Earthquake was not -230,000 people died in the Sumatra Earthquake, while only 16,000 people died in the Tohoku Earthquake
230,000 people died in the Sumatra Earthquake, while only 16,000 people died in the Tohoku Earthquake
What do you need to determine the latitude, longitude, and origin time of an earthquake? -how many people felt the quake, where those people are located, and how much damage the quake caused at those locations -3 different S-P magnitude differences -3 different S-P time differences and their locations -the magnitude of the P-waves at 3 different locations
3 different S-P time differences and their locations
What is the Richter magnitude below? -5.0 -3.0 -7.0 -1.0
5.0
If the total rupture length of the M9 Sumatra earthquake was about 1,300 km, what was the approximate rupture duration? -50 seconds -5,000 seconds -500 seconds
500 seconds
What is the probability of one or more magnitude 6.7 or greater earthquake(s) in the Bay Area in the next 30 years (from the UCERF2 report)? -63% -0% -100% -12%
63%
Here is an InSAR image of Three Sisters Uplift in Oregon. If each fringe represents a change of 2.8 cm. What is the total amount of uplift from 1996 to 2001? -2-5 cm -40-70 cm -14-17 cm -8-11 cm
8-11 cm
Why is it more likely for a large earthquake to occur on the Hayward Fault than on the San Andreas Fault? -Scientists know more about the San Andreas Fault than they do about the Hayward Fault -more people live on the Hayward Fault than on the San Andreas Fault -A major earthquake has occurrd on the San Andreas Fault more recently than a major earthquake on the Hayward Fault -The Hayward fault must accomodate a greater percentage of the plate boundary motion than the San Andreas Fault
A major earthquake has occurrd on the San Andreas Fault more recently than a major earthquake on the Hayward Fault
What caused the tear in the subducting Juan de Fuca Plate? -the tear was created when the Juan de Fuca Plate was formed at the mid-ocean ridge -no one has any idea -half of the plate got caught on the North American Plate while subducting -A rising mantle plume/upcoming hot spot
A rising mantle plume/upcoming hot spot
Choose the true statement. -Earthquakes can occur as much as 1000 km deep in the earth. -Earthquakes occur at a singular point in space and time. -Aftershocks just randomly occur and can not give us any clues about the total size of the ruptured fault. -All earthquakes rupture some piece of a fault. They have a duration time and a length scale in space.
All earthquakes rupture some piece of a fault. They have a duration time and a length scale in space.
How can we reduce the risk of harm using earthquake early warning? -doing drop, take cover, and hold on -Isolating hazardous machinery and chemicals -All of them -automatically opening fire station garage doors -Slowing or stopping trains
All of them
What factors control shaking intensity at a site? -the magnitude of the earthquake -The distance of the site to the fault rupture -Ground condition at the site -All of them
All of them
What evidence was used to conclude that there was a gigantic earthquake in the Pacific Northwest 300 years ago? -Tsunami record in Japan -preserved old tree stumps on the beach -Sudden land subsidence -All of these
All of these
This diagram shows earthquakes occurring almost sequentially from east to west along the North Anatolian Fault. What can be said, generally, about this fault? -smaller earthquakes usually lead to bigger earthquakes -earthquakes occur randomly along the fault -the entire fault ruptures every time there is an earthquake on the North Anatolian Fault -every time a M7+ earthquake happened, it was another 5 years before another large earthquake could occur -An earthquake on one segment of the fault makes the adjacent segment more likely to fail/ experience an earthquake
An earthquake on one segment of the fault makes the adjacent segment more likely to fail/ experience an earthquake
Choose the false statement. -Magnitude is based on instrumental measurements with seismometers. -Intensity describes what people experienced and the damage that the earthquake did to infrastructure and buildings. -Both earthquake intensity and magnitude are on a scale of 1 to 10, so they should always have a similar value no matter where you are. -The value of Intensity should vary by locations whereas there an earthquake will only have one magnitude value.
Both earthquake intensity and magnitude are on a scale of 1 to 10, so they should always have a similar value no matter where you are.
For what purpose was the first global seismic network built? -Exploring the interior of the Earth -Understanding the rupture process of earthquakes -Detecting nuclear tests
Detecting nuclear tests
In the "Drop, Cover and Hold on" 2012 and 2015 New Zealand earthquake drills, what was the most common reason for people not participating? -Embarrassment -Too busy -Physical disabilities -Restrictive clothing
Embarrassment
Which statement is true? -For a while, regulators and industry didn't accept scientific evidence that wastewater injection causes earthquakes, but now they work with scientists to mitigate the hazard -In 2015, regulators and industry didn't want to accept scientific evidence that wastewater injection can cause earthquakes, and they continue to refuse to address the problem
For a while, regulators and industry didn't accept scientific evidence that wastewater injection causes earthquakes, but now they work with scientists to mitigate the hazard
Why is the wastewater that gets extracted alongside fracked hydrocarbons so salty? -Hydrocarbons are the byproduct of ancient sea life, which gets trapped alongside seawater, which in turn becomes increasingly salty with time -the fracking fluids used to extract hydrocarbons contain a lot of dissolved compounds that make it very salty -The tears of Oski after losing the "Big Game" almost every year are funneled into areas with hydrocarbons.
Hydrocarbons are the byproduct of ancient sea life, which gets trapped alongside seawater, which in turn becomes increasingly salty with time
When will you receive an alert on My Shake? -If you and in California or Oregon and there is a magnitude 4.5 or greater earthquake, and the predicted shaking in your area is light to severe. -When there is a magnitude 5 or greater anywhere in the world
If you and in California or Oregon and there is a magnitude 4.5 or greater earthquake, and the predicted shaking in your area is light to severe.
Which remote sensing technology allows us to determine the amount of permanent deformation caused by an earthquake or volcano? -seismometers -GPS -motion tensors -InSAR
InSAR
What elements are required for a useful earthquake prediction? -Interval of time + location + magnitude range + probability -Just a location -Just a time range -Time range + location
Interval of time + location + magnitude range + probability
Which of the following is a surface wave that has side-to-side particle motion in the horizontal plane? -P-wave -Love wave -S-wave -Rayleigh wave
Love wave
What is the largest earthquake caused by injection in the US? -M5.8 Pawnee Earthquake -M7.1 Ridegcrest Earthquake -M9 Devonian Earthquake -M5 Shire Earthquake
M5.8 Pawnee Earthquake
What is true about an ocean-bottom seismometer (OBS)? -OBS stay at a cold, corrosive environmen -The inside battery can last more than 3 years -Divers have to go into the deep water to make sure they have deployed properly -A remote-operation vehicle can move around quickly in the deep sea
OBS stay at a cold, corrosive environment
What's a method for determining the age of a tectonic plate? -Observing polarity reversal of magnetic stripes on the ocean floor -Comparing similar fossils in different places -Mapping where earthquakes occur
Observing polarity reversal of magnetic stripes on the ocean floor
What is the definition of earthquake prediction? -Predicting an earthquake event, specifically its date and time, its location, and the magnitude -Estimates of the probability of occurances of earthquakes in an area over a set time period
Predicting an earthquake event, specifically its date and time, its location, and the magnitude
Which of the following is a surface wave that has circular motion in the vertical plane? -P-wave -S-wave -Rayleigh wave -Love wave
Rayleigh wave
Which of the following is a body wave that is second to show up on seismograph, is defined by shear motion, and is felt horizontally? -P-wave -S-wave -Rayleigh wave -Love wave
S-wave
In the UCERF report, what were the 3 Californian faults that had the greatest probabilities of experiencing one or more magnitude 6.7 or greater earthquakes(s) in the next 30 years? -Southern San Andreas fault, Hayward fault/Rodgers-Creek fault, and the San Jacinto fault -Garlock fault, North San Andreas fault, and the Caleveras fault -The Elsinore fault, Hayward fault, and the Cascadia megathrust
Southern San Andreas fault, Hayward fault/Rodgers-Creek fault, and the San Jacinto fault
Which one of these statements is true? -The North Anatolian and San Andreas faults have a similar size and character. -On the North Anatolian fault, an earthquake on one segment cannot cause the next segment to fail. -We can precisely predict when an earthquake will occur in Istanbul. -Based on the historical record, Istanbul (or Constantinople) has never experienced a big earthquake.
The North Anatolian and San Andreas faults have a similar size and character.
Which of these best describes the definition of magnitude? -the height of the seismic waves -how widely felt the earthquake was -The amount of energy released by an earthquake -The strength of shaking felt on the surface in a particular place
The amount of energy released by an earthquake
What is true about earthquake early warning? -Since there is almost no data transmission and process latency, everyone can get the earthquake early warning immediately. -To better estimate the earthquake location, both of P-wave and S-wave are used for Earthquake early warning. -The fast-moving P-wave is first to arrive, but the damage is caused by the slower S-waves and surface waves. -Earthquake early warning is one kind of earthquake predictions.
The fast-moving P-wave is first to arrive, but the damage is caused by the slower S-waves and surface waves.
Choose the false statement. -GPS stations measure the permanent deformation of an earthquake while seismic stations measure the motion of an earthquake, either acceleration or velocity. So they are very different observations. -If an earthquake is big enough, that we could actually observe the rupture processes on both GPS stations and seismic stations. -The slip models that estimate the amount of slip on the fault plane should have the exact same pattern no matter if we use GPS observation or seismic data. -Permanent GPS stations measure how the surface of the Earth is moving, including sudden displacement in the earthquake.
The slip models that estimate the amount of slip on the fault plane should have the exact same pattern no matter if we use GPS observation or seismic data.
Which of these best describes intensity? -The height of the seismic waves -The strength of earthquake shaking in a particular location -The stress difference on the fault before and after an earthquake -The amount of energy released by an earthquake
The strength of earthquake shaking in a particular location
Which statement is true? -Tsunami waves are more like a thick wall of water than a regular wave -Tsunami waves are just like normal ocean waves except taller.
Tsunami waves are more like a thick wall of water than a regular wave
Based on turbidite (underwater landslide) records, we know that earthquakes occur in the Pacific Northwest area. What of the following statements about turbidites is true? -Turbidite currents caused by earthquakes can only travel very short distances on the seafloor. -Turbidite records show that up to 1,000 kilometers of fault length could fail if the entire margin ruptured in an earthquake at once. -Turbidite drill core records show that the recurrence interval of earthquakes in the Pacific Northwest is periodic (meaning earthquakes occur at regular intervals), which means we can easily predict the magnitude, location, and date for a future earthquake. -When scientists extracted a drill core, all the layers got mixed together, making it very difficult to recognize individual turbidite records.
Turbidite records show that up to 1,000 kilometers of fault length could fail if the entire margin ruptured in an earthquake at once.
According to the Modified Mercalli Intensity (MMI) Scale, what is the proper MMI intensity in the comic? -I -IX -VI -III
VI
Which statement is true about earthquake early warning? -Warnings are triggered by the fast-moving P-wave, before the the slower S-waves and surface waves arrive. -Both the P-wave and S-wave data are used for earthquake early warning. -The only contries with earthquake early warning systems are USA and Japan
Warnings are triggered by the fast-moving P-wave, before the the slower S-waves and surface waves arrive.
Do actual tall buildings in countries like Japan and the US really sway during large earthquakes? -Yes, and this is bad because it means the buildings aren't built sturdy enough -Yes, and this is good because it helps absorb the earthquake energy -No, real buildings are built to be more rigid than is shown in the San Andreas movie -No, but they should because it would be safer
Yes, and this is good because it helps absorb the earthquake energy
What are earthquakes? -shaking caused by large landslides -a release of built up stress on a fault -a chemical explosion that occurs underground -waves of energy propagating through the earth caused by large tsunamis
a release of built up stress on a fault
True or false: Induced earthquakes will immediately stop if you stop injecting fluid into a longstanding wastewater well.
false
What potential hazards could accompany a large earthquake? -landslides -fire -all of the these -liquefaction -aftershocks
all of the these
What is a useful earthquake prediction? -area of the location -all of them -the interval of time when it will occur -probability earthquake will occur by chance -magnitude range
all of them
A tsunami is created in a subduction zone because the edge of the overriding tectonic plate, which has been _______ as it gets dragged by the subducting plate, suddenly _______.
dragged under; snaps back up
Is it better to live on a creeping fault or a locked fault?
creeping fault
True or false: 100% creeping faults result in S-shaped motion around the fault.
false
True or false: All earthquakes that happen underwater produce a tsunami.
false
True or false: Earthquakes in the Central US are less damaging than an earthquake of similar size in the West.
false
True or false: If you are alive and not seriously injured after a single tsunami wave hits, it is safe for you to return to lower ground.
false
True or false: If you are on a boat directly over the epicenter of an earthquake that causes a tsunami, you will feel the large waves produced.
false
True or false: In the US, wastewater injection causes fewer and less dangerous earthquakes than fracking
false
True or false: Since historic earthquakes in Parkfield have occurred at regular intervals, scientists were able to make a correct, precise prediction about when the next earthquake would occur.
false
True or false: The first tsunami wave is always the most destructive.
false
True or false: We are able to predict earthquakes.
false
When forecasting induced seismicity hazard, researchers like Dr. Rubenstein use parameters like rock properties and injection rates to calculate what? -fluid pressure/ stressing rate -recurrence interval
fluid pressure/ stressing rate
What are faults? -stationary cracks in the Earth's surface -big cracks that open up during an earthquake -fractures in the Earth's crust where there is movement along the fracture. -another name for plate boundary
fractures in the Earth's crust where there is movement along the fracture.
The M7.9 Denali Earthquake was a _____ hazard and a _____ risk.
high; low
What determines whether an earthquake in the ocean causes a tsunami? -how deep under the ocean the earthquake occurs -the type of fault the earthquake occurs on -the ground conditions of the ocean floor where the earthquake occurs -how deep in the crust the epicenter of the earthquake is
how deep in the crust the epicenter of the earthquake is
Put these images in order to reconstruct the sequence of events that results in an earthquake in a subduction zone: -things are normal -overriding plate is dragged down and the other plate bulges up -there is a sudden uplift; tsunami
in this order
Below is an image of 2 possible earthquake scenarios on the Hayward Fault as generated by the Haywired Scenario. The white region in the center of each panel corresponds to the area of the fault that could rupture (i.e. slip) in an earthquake. Do the colored regions represent magnitude or shaking intensity? -magnitude -intensity
intensity
But that was on bedrock, said USGS seismologist Susan Hough. Shaking energy that feeds into softer sediments can increase the ________ felt at the surface and [cause the shaking to] last dramatically longer." -magnitude -intensity
intensity
Movies about earthquakes often show huge cracks opening in the earth. In reality: -cracks like that only open during super big earthquakes, like the M9 in Japan in 2011 -the earth never cracks open during earthquakes -it is possible for small cracks to open as the energy of an earthquake rolls through, but not people-swallowing sized -huge cracks really do gape open like that
it is possible for small cracks to open as the energy of an earthquake rolls through, but not people-swallowing sized
Below is a quote from the Anchorage Daily News about the 2018 M7 earthquake in Alaska. Is the quantity of energy inferred from the earthquake's magnitude or intensity? [The] earthquake just north of Anchorage on Friday morning shredded the earth with 2 million tons of explosive force, and generated 650 aftershocks within 30 hours, some of them large enough to rattle residents all over again, experts say. -magnitude -intensity
magnitude
Read the following description of energy released by the 2004 Northern Sumatra Earthquake from the USGS website. Is what they are describing related to the magnitude or the intensity? The 2004 Sumatra earthquake released an estimated "20×101720×1017Joules, or 475,000 kilotons (475 megatons) of TNT, or the equivalent of 23,000 Nagasaki bombs [worth of energy]." -magnitude -intendity
magnitude
What is seismic moment? -how long the earthquake lasted -measure of energy released by the earthquake -a measurement based on the amplitude of the body and surface waves -the violence of the earthquake shaking
measure of energy released by the earthquake
Before the Parkfield earthquake in 2004 occurred, which precursory signal did scientists observe? -increase in low-level seismic activity -groundwater level changes -no precursory signals were observed -increase in fault creep rate
no precursory signals were observed
Can we predict an earthquake? -yes -no
no, we cannot
Which of the following is created by tensile and lengthening forces and creates basins. -strike-slip faults -normal faults -reverse faults
normal faults
The Haywired Scenario is: -a representation of what actually happened when the Hayward Fault experienced a major earthquake in 2018 -a possible outcome of a major San Andreas Fault earthquake in the modern day -one possible version of how a M7.0 earthquake could play out on the Hayward Fault -an exact prediction of what will happen when we have a M7.0 on the Hayward Fault
one possible version of how a M7.0 earthquake could play out on the Hayward Fault
Which of the following is a type of body wave that is the first to show up on a seismograph, is defined by push and pull motion, and is felt vertically. -P-wave -S-wave -Rayleigh wave -Love wave
p-wave
What is the underlying model that allows us to determine earthquake probability? -plate tectonics -liquifaction model -animal behavior -lunar phases
plate tectonics
Which of the following is created by compressive and shortening forces and creates mountains? -reverse faults -normal faults -strike-slip faults
reverse faults
How do you calculate the amount of slip left to be accommodated by earthquakes? -subtract the long term buildup (stream channel offset) from the steady slip (short term offset - curb offset) -subtract the steady slip (short term offset - curb offseet) from the long term buildup (stream channel offset) -divide the slip rate by the amount of time since an earthquake
subtract the steady slip (short term offset - curb offseet) from the long term buildup (stream channel offset)
What does it mean for an earthquake to be induced? -the earthquake causes extra vibrations -the earthquake was man made/caused by humans -the earthquake was not on a fault -human activity caused the magnitude of the earthquake to be exagerated
the earthquake was man made/caused by humans
How does wastewater injection cause earthquakes? -the fluid injected into the ground opens up the fault plane, allowing slip to occur (resistance to slip is decreased) -the salt in the wastewater caused a chemical reaction that creates explosions underground -The wastewater injection fractures the rock, creating an earthquake
the fluid injected into the ground opens up the fault plane, allowing slip to occur (resistance to slip is decreased)
What do you need in order to calculate the slip-rate along a fault that offsets a stream channel? -the length of the offset and the age of the fault -the age of the stream channel and the age of the fault -the length of the offset and the length of the stream channel -the length of the offset and the age of the stream channel
the length of the offset and the age of the stream channel
What is the deepest depth range that an earthquake could occur within the Earth? -the mantle -the inner core -the crust -the outer core
the mantle
Why is the curb in Hayward not aligned? -the motion on the Hayward Fault is causing the surface to move -a car accident damaged to curb -it was built that way to accommodate for the fault motion -poor construction
the motion on the Hayward Fault is causing the surface to move
Why is it more difficult to determine whether an earthquake is natural or man made in California than in Oklahoma and Northern Texas? -there is more oil extraction in Oklahoma and Northern Texas than in California -earthquakes occur more frequently in Oklahoma and Northern Texas -there is no regular time interval for earthquakes in California -there is a lot more natural seismicity in California than there is in Oklahoma and Northern Texas
there is a lot more natural seismicity in California than there is in Oklahoma and Northern Texas
True or false: Damaging tsunamis are preceded by a significant recession of water from the shore.
true
True or false: The 2004 Sumatra tsunami still holds the record for the greatest number of fatalities from a tsunami in recorded history.
true
True or false: The San Andreas Fault is mostly locked in Northern and Southern California, but is creeping in Central California (above Parkfield).
true
True or false: Tsunami require vertical displacement of the seafloor to occur.
true
What is the first motion felt anywhere from an explosive source? -left -right -down -up
up
_______ is long term, injects large volumes of fluid, and causes many felt earthquakes. ______ is short term, injects small volumes of fluid, and cause few felt earthquakes.
wastewater injection ; hydraulic fracturing
Have there been big earthquakes on the Hayward Fault? -yes -no
yes
