The Sea Floor
Earthquakes
- If density increases, the velocity of a P wave should (according to the equation):
- stay the same
- increase
- decrease
- If a P wave were to go from a rock to a liquid - what would happen to its
velocity?
- stay the same
- increase
- decrease
- go to zero
- If an S wave were to go from a rock to a liquid - what would happen to its velocity (use the equation)
- stay the same
- increase
- decrease
- go to zero
- Think of a boundary where a P and S wave would go from solid to liquid (100%) or liquid to solid.
- outer core - mantle
- lithosphere - asthenosphere
- inner core - outer core
- 1 and 4 are both correct
- Body waves consist of the:
- P waves only
- S waves only
- P and S waves
- Surface waves
- With increasing travel time the difference in arrival times between the P and the S waves:
- increases
- decreases
- stays constant
- none of the above
- Earthquake has a RIchter magnitude of 7 as compared with earthquake B's 5. The difference in wave amplitude between B and A is:
- 100X
- 2X
- .01X
- 12X
- In general, the most destructive earthquake waves are the:
- P
- S
- Surface
- horizontal
- Where is the focus with respect to the epicenter:
- directly above
- directly below
- on the other side of the Earth
- none of the above
- Which waves are recorded by a seismograph located in the shadow zone of an earthquake?
- P
- S
- Surface
- all are recorded
Interior of the Earth
- Which one of the following term associations most accurately describes
oceanic crust?
- basaltic; density of 3.0 g/cm3
- granitic; density of 3.0 g/cm3
- quartz arenites of 2.6 g/cm3
- granitic, density of 2.6 g/cc
- The Moho separates:
- the outer core from the inner core
- the asthenosphere from the mesosphere
- the lithosphere from the asthenosphere
- the crust from the mantle
- Which one of the following term associations is FALSE?
- asthenosphere --- plastic
- lithosphere --- rigid solid
- outer core --- rigid solid
- oceanic crust --- rigid solid
- continental crust --- rigid solid
- To induce a positive Bouguer anomaly, a rock unit should have the following
property:
- transmit only P waves
- be denser than average
- transmit only L waves
- demonstrate magnetic inclination
- lie within the seismic shadow zone
- The lithosphere represents:
- crust and uppermost, rigid mantle
- uppermost rigid mantle, only
- asthenosphere and the mesosphere
- outer core and the inner core
- A magnetic material _________ its magnetic character at its Curie temperature:
- gains (on cooling below)
- looses (on heating above)
- both are correct
Plate Tectonics
- Transform faults:
- often offset spreading centers
- can cut across continents
- involve horizontal movement
- all of the above
- Stretching streses, basaltic lavas, and shallow earthquakes are associated with:
- subduction zones
- continent/continent convergence
- spreading centers
- transform fault boundaries
- Compressive streses, granitic magmas, and intermediate depth earthquakes are associated with:
- subduction zones
- continent/continent convergence
- spreading centers
- transform fault boundaries
- Shearing stresses and shallow earthquakes are associated with:
- subduction zones
- continent/continent convergence
- spreading centers
- transform fault boundaries
- If the Atlantic Ocean is widening at a rate of 3 cm per year how far (in
kilometers) will it spread in a million years?
- 300 km
- 30 km
- 30 miles
- 3 km
- In 50 million years?
- 1500 km
- 150 km
- 150 miles
- 1500 miles
- At convergent plate boundaries of oceanic and continental crust:
- oceanic crust is subducted
- continental crust is subducted
- oceanic crust is created
- crustal rifting occurs
- no associated volcanism occurs
- One remarkable realization associated with the discovery of seafloor spreading
was that:
- the crust of continents is denser than that of oceans
- mountains are denser than the mantle
- compared to continents, the crustal floor of the oceans is very young
- the Earth's magnetic field arises from the upper mantle
- the Earth's magnetic field is restricted to oceanic ridges
- Which segment of the Atlantic Ocean opened first?
- northern
- central
- southern
- all of it opened at the same time
- Which one of the following statements best defines Pangaea?
- all of the Earth's continental masses together
- all of the continents of the Southern Hemisphere, only
- all of the continents of the Northern Hemisphere, only
- Africa, Madagascar, and the Indian subcontinent, only
- Europe, Greenland, and North America, only
- If the pacific plate and the North American plate continue to move in the same sense Los Angeles and San Francisco will lie at the same latitude:
- True
- False
- I saw a bumper sticker that said "Reunite Gondwana Land". Which of the following would not be part of this reconstruction?
- Antarctica
- India south of the Himayalays
- Australia
- Africa, Madagascar, and the Indian subcontinent, only
- North America
- Loihi excites geologists because it represents a:
- new instrument for detecting volcanic gases
- new instrument for detecting lava composition
- satellite that can monitor worldwide volcanic activity
- volcano that will become a new Hawaiian island
- satellite that can monitor worldwide earthquake activity
The Universe
- With the exception of Pluto, the outer planets:
- are bigger and higher density
- are bigger and lower density
- are smaller and higher density
- are smaller and lower density
- Stishovite (recall form Chapter 2) and quartz are polymorphs. The fundamental difference is that in stishovite the silicon ion is surrounded by 6 oxygens where as in quartz the silicon ion is surrounded by 4 oxygens. Therefore, in an impact structure which polymorph would form if the pressure was sufficiently high?
- quartz
- stishovite
- All of the planets have at least one moon:
- True
- False
- Venus has a higher albedo than Earth. Therefore, Venus absorbs more of the incident solar radiation than Earth.
- True
- False
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