Discovering Plate Tectonics through Plate Boundaries Flashcards
Where are earthquakes concentrated?
along plate boundaries
How are earthquakes around mid-ocean ridges?
shallow with a narrow linear concentration
How are earthquakes around California?
shallow and along plate boundaries
How are earthquakes around the Alps and Himalayas?
locally dense and shallow
How are earthquakes around Japan, Fiji, South America, and Alaska?
broad regions of depth varying earthquakes
Where do earthquakes occur?
along ALL active plate boundaries
How are volcanoes near California and Washington?
dispersed and widely spaced along continental margins
How are volcanoes around Iceland?
irregular in ocean basins along mid-ocean ridges
How are volcanoes around Hawaii?
linear chain within plates (not at boundaries)
Where are volcanoes found?
MANY active plate boundaries but also WITHIN plates
Why do volcanoes occur within plates?
…
What is the distribution of volcanoes?
linear and closely spaced on continental margins or island chains
What happens to the age of the seafloor when you move away from mid-ocean ridges?
the age increases
How is the crustal growth at the East Pacific Rise?
fast because the band on the geochronology map is wide
How is the crustal growth at the Mid-Atlantic Ridge and Iceland?
slow because the band on the geochronology map is narrow
What is found at the jagged speeding ridges?
factor and transform zones
What part of the Earth do we mean by lithosphere?
outer shell, crust, and upper mantle
What is the asthenosphere?
part of the mantle beneath lithosphere
What are the three different types of plate boundaries?
divergent, convergent, transform
Divergent:
moving apart
Convergent:
moving together
Transform:
moving past each other
Where do divergent plate boundaries start?
within a continent
What do divergent plate boundaries grow?
it becomes an ocean basin
How do mid-ocean ridges form magma chambers?
decompression melting
Why are magma chambers important?
magma can be extruded to the surface to form new oceanic crust
