Oceanography Midterm 2
Ocean circulation patterns
All of the following provide evidence for the early continental drift model except:
Deep-sea trenches
Passive continental margins are characterized by all of the following except:
4-5 billions years
Radioactive isotopes can sometimes be used to determine the:
Solids
S (secondary) waves would travel through the following layers:
Chemical weathering, dissolved materials in river water, erosion of the continents & volcanic activity
Salts in the ocean are derived from the following sources:
the magnetic pattern on the seafloor
Scientists (Vine and Matthews) determined that new ocean floor was being produced at ocean ridges by examining:
The patterns of S and P waves
Scientists discovered that the outer core of Earth is liquid by using:
70%
Seawater covers approximately what percent of Earth's surface?
The Universe is expanding
The "red shift" of starts in our Universe is the best evidence for what?
Moving over a mantle hot spot
The Hawaiian Island are located where the Pacific plate it:
A new linear sea
The Red Sea is an example of:
Antarctic
Which main ocean is the largest and the deepest?
Upwarping & Rift Valley formation
Which of the following is associated with early stages of continental rifting?
Outer core
Which part of Earth's layers is liquid?
fringing coral reef
Which stage in the development of coral reefs is most mature?
trench
Which type of geologic feature(s) would be most-associated with an active oceanic-continental margin?
passive margin
Which type of margin would be most associated with submarine canyons and turbidity currents?
Distance from the Sun
Which unique condition appear to cause Earth to have oceans?
Plants lived near the poles, but have drifted to current locations
Fossils of ancient polar plants are currently found near the equator because the:
Radioactivity in the mantle
Heat for convection within Earth comes primarily from:
Indirect observation
Most of what we know about our solar systems (outside of planet Earth) is through:
Crust, Lithosphere, Asthenosphere & Outer core
P (primary) waves would travel through the following layers:
Transform
Volcanism is not associated with which plate tectonic boundary?
turbidity current
A sediment-laden current that flows off the continental slop is called a:
25%
After two half-lives of a radioactive material, how much of the original radioactive material is left?
4 billions years
Approximately how old are Earth's oceans?
Atlantic
As a result of modern plate tectonics, which major ocean is getting larger?
Mountain building, volcanism, & earthquakes
As an oceanic plate converges with a continental plate, the following is likely to occur:
Island arc formation & volcanism
As an oceanic plate converges with an oceanic plate, the following is likely to occur:
age of the seafloor
Confirmation of seafloor spreading was supported by the:
less dense than ocean crust and it is generally thicker
Continents "float" higher above the mantle than the ocean basins because continental crust is:
Isostasy
Differences in height between continental crust and oceanic crust (as they "float" on the athenosphere) are best explained by:
Very toxic compared to our modern atmosphere
Earth's early atmosphere with respect to it chemical nature was:
Convergent, divergent & transform
Earthquakes are associated with which boundaries?
New oceanic crust must be created at the mid-ocean ridge & old oceanic crust is being recycled at the continental margins
If the age of the seafloor increases from the mid-ocean ridge toward the continents, what must be true?
How much salt (kg/cubic meter) is in the oceans, input of salts (rivers), outputs of salts (shells and minerals) & volume of water in the oceans
In order to develop a simple mass balance of salt content in the oceans over geologic time, which items below would you need to know?
Asthenosphere
In the outermost 700 km of Earth's structure, which part is capable of flow?
Galaxy, solar system & planet
The correct arrangement of astronomical bodies from oldest to youngest is:
contain rift valleys
The crests of mid-ocean ridges:
Outgassing & volcanism
The development of water on Earth primarily was the result of:
Convergent boundary (Continent-continent)
The formation of the Himalaya Mountains, in Asia, is the result of:
Sound waves
The indirect method that is most frequently used to investigate sediment and rock layers of the seafloor is:
They are buried from sediment derived from the passive margin
The main reason abyssal hills or seamounts are not as common on passive margins is:
A reasonable driving mechanism
The major weakness of the early continental drift model was:
divergent boundary
The mid-ocean ridge is an example of a:
All bodies in the solar system formed from an enormous gas cloud
The nebular hypothesis suggests that:
Showing the seafloor spreading was occurring & supposing that convection currents in Earth's interior drive plate movements
The plate tectonics theory greatly improved on the continental drift model by:
Are offset and perpendicular to the main axis of the mid-ocean ridge
Transform boundaries associated with mid-ocean ridges:
Differing densities of the rock and mineral materials
The separation of the Earth into layers was the result of the:
Mid-ocean ridge
The youngest oceanic crust is located near the:
Convergent boundary (oceanic-oceanic)
Volcanic (or Island) Arcs are associated with which type of boundaries?