Geologic Structures/ Earthquakes/ Earth's Interior Vocabulary Flashcards
To be able to identify the vocabulary in this unit.
Anticline
An arched fold in which the rock layers usually dip away from the axis of the fold.
Asthenosphere
A region of Earth’s outer shell beneath the lithosphere. The asthenosphere is of indeterminate thickness and behaves plastically.
Benoiff Zone
Distinct earthquake zone that begins at an oceanic trench and slopes landward and downward into Earth at an angle of about 30* to 60*.
Body Wave
Seismic wave that travels through Earth’s interior.
Elastic Limit
The maximum amount of stress that can be applied to a body before it deforms in a permanent way by bending or breaking.
Epicenter
The point on Earth’s surface directly above the focus of an earthquake.
Focus
The point within Earth from which seismic waves originate in an earthquake.
Isostacy
The balance or equilibrium between adjacent blocks of crust resting on a plastic mantle.
Joint
A fracture or crack in bedrock along which essentially no displacement has occurred.
Lithosphere
The rigid outer shell of Earth, 70 to 125 or more kilometers thick.
Magnitude
A measure of the energy released during an earthquake.
Mercalli Scale
Scale expressing intensities of earthquakes (judged on amount of damage done) in Roman numerals ranging from I to XII.
Normal Fault
A fault in which the hanging- wall block moved down relative to the footwall block.
Orogeny
An episode of intense deformation of the rocks in a region, generally accompanied by metamorphism and plutonic activity.
Precambrian Shield
A complex of old Precambrian metamorphic and plutonic rocks exposed over a large area.
