Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
The modern scientific theory which describes the movement of Earth's outer layer |
Plate Tectonics |
|
lithosphere |
the uppermost mantle along with the overlying curst, behave as a strong, rigid layer |
|
Lithospheric plates or plates |
moves as a unit over the material of the asthenosphere |
|
divergent plate boundaries |
two plates move apart |
|
convergent plate boundaries (Subduction zone) |
two plates move towards one another |
|
transform fault boundaries |
two plates grind past each other |
|
straitions |
scratches or groves created by glacial debris as it moves. |
|
magma |
a body of molten rock found at depth include any dissolve gases and crystals |
|
seafloor spreading |
new oceanic crust is produced at the crests of mid-ocean ridges |
|
continental rifting |
the landmass may split into two or more smaller continents |
|
rift valley |
the crust fractures to form a long trough |
|
melt |
the liquid portion of magma excluding the solid crystals |
|
basaltic |
fine-grained igneous rock of mafic composition |
|
earthquake |
the vibration of earth, produced by the rapid release of energy |
|
focus |
energy radiates in all direction from its source |
|
faults |
a break in rock mass along which movement has occured |
|
elastic rebound |
the sudden release of stored strain in rocks that result in movement along the fault |
|
seismology |
the study of earthquake waves |
|
Seismographs |
instruments that record seismic waves |
|
surface waves |
waves traveling along the outer part of earth |
|
body waves |
waves travel through the earths interior |
|
primary Waves |
alternating compression and expansion of material through which it passes. Push and Pull |
|
secondary waves |
oscillation perpendicular to the direction of propagation shake |
|
epicenter |
the point on earth's surface directly above the focus |
|
deep-focus earthquakes |
focus greater than 300 kilometers |
|
inner core |
a solid, iron-rich, sphere having a diameter of 2432 kilometers |
|
outer core |
a fluid metallic layer some 2270 kilometers thick |
|
mantle |
a solid, rocky layer having a thickness of about 2885 kilometers |
|
crust |
a very thin outer skin that ranges from about 7 to more than 70 kolometers thick |