Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

27 Cards in this Set

  • Front
  • Back
  • 3rd side (hint)

The depth of a hypocentres of earthquakes at oceanic spreading centres is how deep?

Generally less then 80 km deep

The depth of hypocentres of earthquakes at subduction zones are how deep?

Very variable, from near surface to to more then 500 km

As compared to the Asthenosphere, the lithosphere is...

Cooler and less able to flow

Unlike the lithosphere, the Asthenosphere is...

Is able to flow over long periods of time

Which lithosphere is thickest?

Continental lithosphere

The lithosphere is generally thinnest near which plate boundary?

Divergent plate boundaries

The lithosphere of the earth is generally thickest at or near which plate boundary?

Convergent plate boundaries

The lithosphere is composed of the...

Crust and upper most part of the mantel

The potential temperature of "normal" upper-mantel, away from hotspots, is accepted to be...

1300 degrees Centigrade

The thermal gradient in the Asthenosphere is approximately...

0.5 degrees C per km

The velocity of seismic waves traveling through from earthquake foci...

Generally increase with depth, but with abrupt changes called "seismic discontinuities"

Do seismic waves travel at greater velocities in solids then in liquids?


Can P waves travel through liquids?


Are these two objects in isostatic equilibrium with one another?


Why are hypothermal "black smokers" on the pacific sea floor black?

Because of fine grained sulphide minerals suspended in super heated sea water.

This typical basalt erupted a the submarine environment. This lava flow morphology is commonly known as...

Pillow basalt.

The boundary between the crust and the mantle is marked by a seismic velocity discontinuity called...

The Moho

At oceanic spreading centers, earth's upper mantle is...

The same temperature as elsewhere on earth.

Heat transfer in the crust is largely by...


Heat transfer in the Asthenosphere is largely by...


The light green represents...

The pressure and temperature conditions under which both melt and solid are present

The dark green represents...

The pressure and temperature conditions under which the mantel is entirely molten

How does the mantle melt at oceanic spreading centers

By decompression, with no significant thermal anomaly

At hotspots the mantle is of oder of _____ hotter then "normal" mentel

200 degrees Centigrade


The mantle melts at subduction zones as a result of...

The addition of volatiles from dehydration of the down-going lithospheric slab

Hot spots are caused by...

Hot plumes of mantle material that rises up from the core mantle boundary.

The diagram shows two subduction zones, with the down-going subducting plate moving from right to left. The depth of the earthquake hypocentres is shown by the coloured dots. What does this information tell us about the subduction slab?

The slab dip is greater in B than in A