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Quiz November 26
Plate Techtonics
36
Science
9th Grade
11/26/2007

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Cards

Term
Earth’s interior is made up of
Definition
Silicon, Oxygen, Iron, and Magnesium
Term
Crust
Definition

outer part of earth which is rocky; it is thinner at the ocean than at continents.

Term
Moho discontinuity
Definition
boundary about 40 km below surface, 7 km on ocean floor
Term
Lithosphere
Definition
the crust and upper mantle it floats on the Asthenosphere
Term
Asthenosphere
Definition
near top of; mantle, high temp. and pressure causes small melting of rock. – Less dense rock rises and others sink
Term
2 parts of the core and contents
Definition
outer is liquid, probably made of iron, responsible for magnetic field. Inner is sold, iron and nickel
Term
Convection Cell
Definition
liquid, solids, and gases form cells, bring new rock to crust. Evidence suggest entire continent drift on convection
Term
Seismic gap
Definition
Area where plates stick together as they try to move pressure builds and earthquakes occur
Term
Focus
Definition

source of earthquake waves travel in all directions below surface

Term
Epicenter
Definition

on surface above focus

Term
P waves
Definition
primary waves) fast moving longitudinal waves. 1rst to reach equipment. Also, it can travel through any material
Term
S waves
Definition
(Secondary waves) slow moving transverse waves. They move side to side, through solids only
Term
Surface waves
Definition
(L waves) – interaction of p and s waves, cause surface to shake and roll, worst destruction
Term
Shadow Zone
Definition
area in Earth not affected by P and S waves because of density of material
Term
Seismograph
Definition
instrument used to record earthquakes need S location to locate epicenter
Term
Richter scale
Definition
size and magnitude of earthquakes measures amount of energy released
Term
Alfred Wedener
Definition
hypothesized continents were once joined together called Pangaea
Term
Volcanoes
Definition
in crust through which magma reaches Earth’s surface
Term
“Ring of Fire”
Definition
edge of Pacific Ocean lots of volcanoes and earthquakes
Term
Fold
Definition
bend in rock caused by force
Term
Orogeny
Definition
  • process of mountain building (orogenic belts) – Rock mountains
Term
Uplift
Definition

large areas lifted without breaking rocks

Term
Anticline
Definition

Upward fold

Term
Syncline
Definition
Downward Fold
Term
Dip
Definition
angle at which rock layer is tilted from horizontal
Term
Strike
Definition
forms a straight line from dip
Term
Fracture
Definition
occurs when force is great enough to break rock and not fold. – no movement along facture is called a joint
Term
Divergent boundary
Definition
area where crust is spreading. – in middle of Atlantic ocean, molten rock from mantle rises through rifts or cracks in ocean floor. – Forms mid – Atlantic Ridge. Also on land as the Great Rift Valley in Africa
Term
Convergent boundary
Definition
when plates press together. Produces mountains, volcanoes, and ocean trenches.  Marianna trench
Term
Subduction zone
Definition
where one plate is forced under another. Oceanic plate under continental plate forming a trench. Marianna trench is 11,000 m deep, greatest depth reached
Term
Transform Faults
Definition
when 2 plates slide past each other in opposite directions. Ex. San Andreas fault
Term
Fault
Definition
form along a fracture where there is movement
Term
Normal fault
Definition

Earth’s crust is pulled apart known as tension. As the crust moves and tilts form Fault Block Mountains

Term
Reverse faults
Definition
when the crust is pushed together known as compression. (Thrust fault) – angle is very low
Term
Lateral fault
Definition
crust drags against each other in opposite directions known as shear. Hanging wall and footwall move parallel to each other. Ex. San Andreas.
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