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

29 Cards in this Set

  • Front
  • Back
Counter-balancing forces w/in Earth
1) Mountain building
2) Erosion and transportation of sediment
Typical Mtn. Volume
V(mtn)= length x height x width
Rate of mtn. erosion
150 m^3/yr
belts where molten rock (magma) form the upper mantle or lower crust come to the surface (lava)
belts where there are planes of weakness and breakage in brittle crustal rocks; site for potential energy conversion mechanical energy or tsunami
Plate Movement
physical displacemnet of great segments of the Earth's crust; can be directly measured using GPS and other technology
Plate Tectonics
Concept that the crust of the Earth is broken up into several (~15) large plates (tectonic plates), as well as several smaller ones
Mantle Convection
Driving force of plate tectonics. Drags plates along and keeps them moving
ocean floors
contain volcanic mountain ranges and spreading center tha demonstrate how the ocean floor is formed at mid-ocean ridges and moves away gradually from these ridges
record of magnetic reversals
- magnetized rock on the ocean floor (basalt) forms a record of earth's magnetic field when cooled
- patterns of magnetization on the sea floor are parallel zones on opposite sidees of mid-ocean ridge
Curie temperature
the temp at which a crystal containing Fe acquires magnetization after forming from a liquid
Plate travel time
T(plate)= D(plate)/Speed(plate)
supercontinent comprised of all land mass that existed about 250 to 140 million years ago
Divergent plate boundaries
new plate material (rock) is formed here; site of volcanism, shallow low-magniture earthquakes
Convergent plate boundaries
plates come together at a rate of a few cm/yr
- crust buckles up to form folded mountain chains (orogeny)
- sea floor crust ois taken back into earth
- volcanoes form from melting during subduction
- great earthquakes occur due to break up of subducting crust
- ocean trenches form as a result of subduction
Transform plate boundaries
- where plates glide past one another along a great crustal fault zone
- powerful earthquakes, but no volcanoes
Volcanoes and plate boundaries: divergent
basaltic (silica-poor) volcanoes that erupt large quantities of lava (non-violent)
Volcanoes and plate boundaries: convergent
silica-rich volcanoes; magma due to melting of subduction plate (violent eruptions)
Volcanoes and plate boundaries: hot spots
local (intra-plate) sites on Earth where plumes of hot, liquid mantle rise and melt through the crust forming huge volcanoes; independent of plate boundaries
Earthquakes and plate boundaries: focus
site of initial earthquake motion in the earth's crust
Earthquakes and plate boundaries: epicenter
map location on the surface above the focus
Earthquakes and plate boundaries: divergent
shallow focus (<10 km) and rather weak
Earthquakes and plate boundaries: convergent
shallow to deep focus (down to 200 km, deepest earthquakes occur) dues to subduction plate breaking up (shallow more common than deep)
Earthquakes and plate boundaries: transform
shallow focus earthquakes that are potentially very powerful if the earthquakes rare, but rather weak if they occur all the time
Earthquakes and plate boundaries: hot spots
shallow focus only; weak but frequent
study of earthquake vibrations and what they can tell us about the earth itself
Wave types
- P-waves (compressional or longitudinal waves)(sound)
- S-waves (transverse waves)(shaking)
- waves in which molecules move back and forth in the same direction as the wave moves
- fast waves that travel several km/sec in through solid rock, liquid and gases
waves in which molecules move up and down perpindicular to the direction of wave motion; slow waves that cannot pass through a liquid or gas (only solid rock)