Which of the following was used as evidence for plate tectonics?
a. topographic profiles of the ocean floors
b. maps on rock magnetism
c. data classifying rocks by age
d. sea floor spreading
e. all of the above
The continents of Eurasia and North America are currently moving apart at an average rate of
5 cm per year
The North American plate
extends from the middle of the Atlantic Ocean to the edge of the Pacific Plate
Example of a continental convergent plate boundary
a. the East African Rift Valley
b. the San Andreas Fault
c. the Atlantic east coast fall line
d. Mount St. Helens in the northwest United States
e. the Himalayan Mountains
Divergent plate boundaries are associated with
a. seafloor spreading.
b. formation of new crust.
c. volcanic action.
d. shallow, low-energy earthquakes.
How often does the oceanic plate material of the Earth renew itself; i.e., go through one replacement cycle?
evert 200 million years
What evidence convinced most scientists to accept the theory of plate tectonics?
a. ocean topography
b. magnetism of the ocean basin rocks
c. discovery of the Mid-Atlantic Rift zone
d. radiometric dating of the basaltic rocks
Wave that is classified as a type of seismic wave following earthquakes?
d. shear waves
T/F: An earthquake with a magnitude 7 on the Richter Scale releases 100 times the energy of an earthquake with a magnitude 5.
T/F: Rocks collected at the Mid-Atlantic Ridge and dated with radioactive isotopes are among the oldest rocks on earth
T/F: Man may have evolved his upright stance from a need to adapt to divergent plate boundaries.
T/F: The specific surface features created by convergent plate boundaries depend on whether the plates are continental or oceanic.
What are the surface features associated with convergent plate boundaries?
Converging plates can result in deep ocean trenches, nonvolcanic mountains, or coastal mountain ranges with an ocean trench offshore.
Subduction zone regions are often the locations of
a. active volcanoes.
b. the disappearance of old plate material.
c. the world's highest mountains.
d. severe earthquakes.
What is the force that moves continents and tectonic plates?
a. convection cells
b. mantle convection
c. radioactive decay
d. heat energy left from the great bombardment
Most mountains have not eroded to a flat plain in the last 500,000 years because
mountains are reformed by tectonic uplift that is greater than or equal to the erosional forces.
The only currently active plate boundary within the continental United States is the
San Andreas Fault
Which of the following would not be seen in the United States?
a. chunks of land called terranes
b. an old spreading "rift" plate boundary
c. a "hot spot" with active volcanoes
d. a mountain range created from the collision of two continents
e. a mountain range formed when molten rock pushed up sediments
The difference between continental and ocean basin rock is
ocean rock are basaltic and continental rocks are granite
T/F: Compared to the oceanic plates, the continental plates are thicker and comprised of lower-density rock.