Chapter 5 Flashcards
What is an Earthquake?
Ground shaking of Earth produced by the rapid release of energy from the slipping of crustal blocks along faults.
What are seismic waves?
A form of energy that travels through the Earth, released during an earthquake.
What is the hypocenter (focus)?
Location within Earth where rock displacement or movement along a fault occurs - source from which energy radiates.
What is the epicenter?
Point on Earth’s surface directly above the hypocenter.
Where do most large earthquakes occur?
Along faults associated with tectonic plate boundaries.
What does earthquake preceded?
Earthquake are produced by foreshock and followed by aftershocks.
What is the foreshock and Aftershock?
The foreshock is an Earthquake with lesser magnitude occur before a major earthquake and it also served as a warning.
Aftershock is an earthquakes of lesser of magnitude, occurs after a major earthquake.
What does convergent & Divergent boundaries produce?
Convergent produces some of the largest earthquake.
Divergent generate small earthquake.
What is a thrust Fault?
IT is when the up-thrown block overrides the down-thrown block at a low angle.
What is a Megathrust Fault?
Is a convergent plate boundary between a sub-ducting slab of oceanic lithosphere or oceanic plate.
What is the Reverse Faults?
Develop front the compressional stress, movement along the fault is usually vertical.
What is the seismology and seismograph?
Seismology is the study of earthquake waves.
Seismograph is the instrument used to record earthquake waves.
Where does Body & surface waves travel around the Earth?
Body waves travel in the Earth’s interior.
Surface waves travels along the outer part of the earth.
Body waves is separated into 2 waves:
P waves and S waves which mean Primary and Secondary,explain P waves in detail ?
P waves are Push, Pull, or expand and compress rocks in the direction.
P waves can travel through solids, liquids and gases.
P waves have greatest velocity of all earthquakes waves.
Body waves is separated into 2 waves:
P waves and S waves which mean Primary and Secondary,explain S waves in detail ?
S waves shake
S waves travel only through solids
S waves have slower velocity
What is Surface waves?
Surface waves have complex motion.
Surface have a the slowest velocity of all waves.
Surface waves have the greatest amplitude.
Surface waves have the greatest destruction earthquake.
What the modified Mercalli intensity scale?
The midfield Mercalli intensity scale measures the intensity of earthquake.
What is a magnitude?
Magnitude is an estimate measure of the amount of energy released at an earthquake’s source obtained form seismograph.
What is the moment magnitude?
It is the correctly estimated the size of medium to large earthquakes.
What are the factors that determine structure damage?
Intensity of the earthquake-intensity of the vibration.
Duration of the vibration.
The nature of the group underneath human-made structures.
The nature of building materials and construction practices in the region.
Where do most earthquakes occur?
Circum pacific belt
Alphonse-Himalayan Belt
What is the circum -Pacific and Alpine-Himalayan Belt?
Circum-pacific Belt is the zone of greatest seismic activity.
Alpine-Himalayan Belt is another major area of strong seismic activity.
What is complex wave behavior and impact of stiffness and compressibility?
Complex wave behavior helps identify boundaries within earth’s interior.
Impact of stiffness and compressibility aid in interpreting rock composition and temperature.
What is the difference between the Inner outer core?
The inner core composed of iron elements.
The outer core composed of metallic iron with smaller amounts of nickel and lighter elements.
