GEOLOGY 201 QUIZ 4 QUESTIONS
AND ANSWERS ALL CORRECT
What is a main shock? - Answer- biggest shock out of a series
How long can after shock last for? - Answer- weeks or months
Does every event have aftershocks? - Answer- No
What zones have the largest earthquakes? - Answer- Subduction zones
What happens to rain water? - Answer- half rain water evaporates and transpires back
into earth
What is watershed? - Answer- region anywhere where raindrop falls will runoff and go
into channel
Relationship between watershed and river network? - Answer- all watershed have river
networks
What is a river network? - Answer- where channels do not exist in isolation
Place of first rupture in an earthquake? - Answer- hypocenter or focus
The projection of focus to surface is? - Answer- epicenter
What is a surface wave? - Answer- seismic waves that travel along the earths surface
What are the types of body waves? - Answer- Non-directional; P & S waves; they are
not confined to the earths surface, travel through earths interior, both elastic
What is a P wave? - Answer- Primary wave. A body wave. generated by a sudden
compression or extension of the ground at the site of an earthquake, push or pull at a
stretched spring
What is an S wave? - Answer- Secondary wave. generated by shearing or sliding
motion at an earthquake site i.e. when rope is shaken
What are the types of surface waves? - Answer- L & R waves
, What is an L wave? - Answer- moves like a snake
What is an R wave? - Answer- up and down waves, comes from P waves, ripple effect
How is the size of an earthquake described? - Answer- its size and magnitude, Mw; it
increases in value as amount of energy released during an earthquake increases;
physical bond for max magnitude of 9.5
Is an earthquake dimensionless? - Answer- Yes; it is on a log scale i.e. not linear
What is the magnitude (Mw) a function of? - Answer- rigid of rock (G-shear modulus),
area of rupture (Af), Displacement of rupture plane/horizontal (Df)
Mo stands for? - Answer- Seismic movement= mxAxD(nm)
Mw stands for? - Answer- Movement magnitude= 2/3 (log10Mo)-6 & is UNITLESS
How do you measure ground shaking? - Answer- seismometer and Mercalli Intensity
Scale
What is a seismometer? - Answer- network of seismographs, typically mounted directly
on bedrock and is often buried
What is the Mercalli Intensity Scale? - Answer- Scale of damage
Where do earthquakes occur? - Answer- along plate boundaries, subduction zones,
rifting boundaries (diverge), collision convergent
How do earthquakes cause damage? - Answer- ground shaking, landslides,
liquefaction, tsunami
What is liquefaction? - Answer- soil, like liquid and flows into pour space and separates
grain
What is a tsunami? - Answer- only if the displacement of ground of ocean basin, only if
land displaces down vertically, water comes out to fill the space and flows back to shore
as a giant wave
What is mass wasting? - Answer- downslope of movement of rock and sediment due to
gravity
What are the two types of hill slopes? - Answer- bedrock and soil-mented
What kind do we have and what kind does Pacific North West have? - Answer- We
have both, PNW has soil-mented
AND ANSWERS ALL CORRECT
What is a main shock? - Answer- biggest shock out of a series
How long can after shock last for? - Answer- weeks or months
Does every event have aftershocks? - Answer- No
What zones have the largest earthquakes? - Answer- Subduction zones
What happens to rain water? - Answer- half rain water evaporates and transpires back
into earth
What is watershed? - Answer- region anywhere where raindrop falls will runoff and go
into channel
Relationship between watershed and river network? - Answer- all watershed have river
networks
What is a river network? - Answer- where channels do not exist in isolation
Place of first rupture in an earthquake? - Answer- hypocenter or focus
The projection of focus to surface is? - Answer- epicenter
What is a surface wave? - Answer- seismic waves that travel along the earths surface
What are the types of body waves? - Answer- Non-directional; P & S waves; they are
not confined to the earths surface, travel through earths interior, both elastic
What is a P wave? - Answer- Primary wave. A body wave. generated by a sudden
compression or extension of the ground at the site of an earthquake, push or pull at a
stretched spring
What is an S wave? - Answer- Secondary wave. generated by shearing or sliding
motion at an earthquake site i.e. when rope is shaken
What are the types of surface waves? - Answer- L & R waves
, What is an L wave? - Answer- moves like a snake
What is an R wave? - Answer- up and down waves, comes from P waves, ripple effect
How is the size of an earthquake described? - Answer- its size and magnitude, Mw; it
increases in value as amount of energy released during an earthquake increases;
physical bond for max magnitude of 9.5
Is an earthquake dimensionless? - Answer- Yes; it is on a log scale i.e. not linear
What is the magnitude (Mw) a function of? - Answer- rigid of rock (G-shear modulus),
area of rupture (Af), Displacement of rupture plane/horizontal (Df)
Mo stands for? - Answer- Seismic movement= mxAxD(nm)
Mw stands for? - Answer- Movement magnitude= 2/3 (log10Mo)-6 & is UNITLESS
How do you measure ground shaking? - Answer- seismometer and Mercalli Intensity
Scale
What is a seismometer? - Answer- network of seismographs, typically mounted directly
on bedrock and is often buried
What is the Mercalli Intensity Scale? - Answer- Scale of damage
Where do earthquakes occur? - Answer- along plate boundaries, subduction zones,
rifting boundaries (diverge), collision convergent
How do earthquakes cause damage? - Answer- ground shaking, landslides,
liquefaction, tsunami
What is liquefaction? - Answer- soil, like liquid and flows into pour space and separates
grain
What is a tsunami? - Answer- only if the displacement of ground of ocean basin, only if
land displaces down vertically, water comes out to fill the space and flows back to shore
as a giant wave
What is mass wasting? - Answer- downslope of movement of rock and sediment due to
gravity
What are the two types of hill slopes? - Answer- bedrock and soil-mented
What kind do we have and what kind does Pacific North West have? - Answer- We
have both, PNW has soil-mented
