Oceanography ch 2
Where would you NOT expect to find significant volcanic activity?
continental collision zone
An ocean trench is associated with what type of plate boundary?
convergent
Plate boundaries where new oceanic crust is being added are called _____________.
divergent boundaries
The solid layer of the Earth that moves and makes up the plates is the .
lithosphere
Where do most earthquakes occur?
plate boundaries
What happens when an oceanic plate meets another oceanic plate?
the older, colder plate is subducted
Which of the following features are found at an oceanic-continental convergent plate boundary?
trench, continental arc, mountains
What is associated with a subduction zone?
volcanic arc
Which of the following features is associated with an oceanic-oceaninc convergent boundary?
volcanic island arc
result(s) from ocean-ocean convergence?
-Japan -Aleutian Islands -Marianas Trench
How do deep ocean trenches form?
An oceanic plate collides with a continental or oceanic plate.
Why are earthquakes mainly found at the edges of plates?
Breakage and deformation of the lithosphere are focused at plate edges
What part of the continents was determined to be the best "fit" when considering evidence for continental drift?
Continental shelf
How does an ocean basin form?
Convection cells in the asthenosphere pull the sea floor apart, and the spreading creates ocean lithosphere in the gap left between the pieces.
Where do most of the largest earthquakes occur?
Convergent plate boundaries
Which of the following statements is true regarding hotspots?
Hotspots are created by mantle plumes.
Which volcano was directly over the Hawaiian hotspot 3 million years ago?
Oahu
How are oceanic ridges different from oceanic rises?
Oceanic rises spread quickly and produce vast amounts of rock while oceanic ridges spread slowly and accumulate steeply.
What tectonic plates are oceanic?
Pacific Plate; Nazca Plate
Which of the following statements is true regarding tectonic plates?
Tectonic plates may include both oceanic and continental crust.
How does the Continental Arc System of mountain building, for a volcano when its near a subduction zone
An oceanic plate collides with a continental plate.
Paleomagnetism can be demonstrated in which of the following examples?
At equal distances from the mid-ocean ridge, the polarity of the Earth's magnetism in the rock is the same.
What is a volcanic arc?
a row of volcanoes that forms on the overriding plate near a subduction zone
As a tool, the modern evidence from paleomagnetism has helped support plate tectonics by showing that ________________.
magnetic sea floor "stripes" are symmetric with respect to the mid-ocean ridge
Which geologic features are associated with divergent boundaries?
mid-ocean ridges and continental rift valleys
Most divergent boundaries are moving slowly. At which of the following locations at divergent boundaries does the quickest movement happen?
oceanic rises
The study of Earth's magnetic field in the geologic past is called .
paleomagnetism
What best describes the tectonic setting of the Cascade Mountains of the Pacific Northwest?
subduction zone
