Upgrade to remove ads
Only $2.99/month

Earth's Interior Vocabulary

Terms in this set (41)

Asthenosphere
the ductile part of the earth just below the lithosphere is about 180 km thick and is found 100-250 km (60-150 mi) below the Earth's surface. The asthenosphere yields to persistent stresses more than the rigid crust or the core.
Body Waves
waves that move within the Earth's interior or within a body of rock. P and S waves are body waves.
Compression
fractional decrease of volume due to pressure.
Focus
the point on the fault at which the first movement or break occurred. Directly beneath the epicenter at 1-50 km depth
Earthquake
shaking or trembling of the earth that accompanies rock movements extending anywhere from the crust to 680 km below the Earth's surface. It is the release of stored elastic energy caused by sudden fracture and movement of rocks inside the Earth. Part of the energy released produces seismic waves, like P, S, and surface waves, that travel outward in all directions from the point of initial rupture. These waves shake the ground as they pass by.
Tectonic Earthquake
earthquake that occurs when the earth's crust breaks due to geological forces on rocks and adjoining plates that cause physical and chemical changes.
Volcanic Earthquakes
earthquakes that result from tectonic forces which occur in conjunction with volcanic activity.
Collapse Earthquakes
small earthquakes in underground caverns and mines that are caused by seismic waves produced from
the explosion of rock on the surface
Explosion Earthquake
earthquakes which are the result of the detonation of nuclear and chemical devices
Elastic Limit
the point at which any additional force to an object will permanently deform its shape
Elastic Properties
the measure of an objects ability to change shape when a force is applied to it, and return to its original shape when the force on it is released
Elastic Rebound
an objects ability to return to its original shape after being broken apart
Elastic Strain
Earthquakes are caused by the sudden release of energy within some limited region of the rocks of the Earth. The energy can be released by elastic strain, gravity, chemical reactions, or even the motion of massive bodies. Of all these the release of elastic strain is the most important cause, because this form of energy is the only kind.
Epicenter
the point on the Earth's surface directly above the focus of an earthquake
Frequency
the number of wave cycles per unit of time that pass a given point.
Hazard
a source of unpredictable, unplanned danger
Intensity
The intensity is a number (written as a Roman numeral) describing the severity of an earthquake in terms of its effects on the earth's surface and on humans and their structures.
Lithosphere
solid, rocky, outer part of the Earth, ~100 km thick (50 miles) comprised of the crust and the solid portion of the mantle. The thickness is age dependent with older lithosphere is thicker than younger oceanic lithosphere. The lithosphere below the crust is brittle enough at some locations to produce earthquakes by faulting, such as within a subducted oceanic plate
Magnitude
is a number that characterizes the relative size of an earthquake
Mantle
the layer in Earth's interior between the crust and the metallic core.
the bulk character of the rock, such as composition, density, elastic moduli, mineralogy, and phase (ex. the presence of melt). Elastic waves may propagate through the earth in a manner which depends on the material properties of the earth. The elasticity of the material provides the restoring force of the wave. When they occur in the Earth as the result of an earthquake or other disturbance, elastic waves are usually called seismic waves.
What are the material properties of the earth?
P Wave (primary body wave)
the first seismic wave detected by seismographs; able to move through both liquid and solid rock.. Also called compressional or longitudinal waves, they compress and expand (oscillate) the ground back and forth in the direction of travel, like sound waves that move back and forth as the waves travel from source to receiver; is the fastest wave.
Seismic Wave
an elastic wave generated by an impulse such as an earthquake or an explosion. these may travel either through the earth's interior (P and S waves; the fastest waves) or along or near the earth's surface (Rayleigh and Love waves); travel at speeds of several kilometers per second.
Seismicity
the geographic and historical distribution (the "where?" and "how often?") of earthquakes
Seismic Tomography
an imaging technique that uses seismic waves generated by earthquakes and
explosions to create computer-generated, three-dimensional images of Earth's interior
Seismogram
A real-time record of earthquake ground motion recorded by a seismograph; These are the records (paper copy or computer image) used to calculate the location and magnitude of an earthquake
Seismograph
an instrument that records vibrations of the Earth, especially earthquakes; generally refers to the
seismometer and a recording device as a single unit
Seismology
science that deals with earthquakes and attendant phenomenon including the study of artificially produced elastic waves
in the Earth's material
Seismometer
a sensitive instrument that can detect waves emitted by even the smallest earthquakes
Shadow Zone
the area of the earth from angular distances of 104 to 140 degrees from a given earthquake that does not receive any direct P waves. This zone results from S waves being stopped entirely by the liquid core and P waves being bent (refracted) by the liquid core.
Surface Wave
waves that move close to or on the outside surface of the Earth rather than through the deep interior like the faster P or S waves. There are two principal types, Love and Rayleigh waves, are generated during an earthquakes; waves that move close to or on the outside surface of the Earth rather than through the deep interior like the faster P or S waves. Two principal types of surface waves, Love and Rayleigh waves, are generated during an earthquake;
these waves produce ground shaking at the Earth's surface but very little motion deep in the Earth.
Rayleigh waves
these types of surface waves cause both vertical and horizontal ground motion, and
Love waves
these types of surface wave cause horizontal motion only
S Waves (secondary body waves)
waves that oscillate the ground perpendicular to the direction of wave travel; will not travel through liquids like water, molten rock, or the Earth's outer core; they produce vertical and horizontal motion in the ground surface.
Wave
disturbance that moves through a system
The crust, mantle, and the inner and outer core.
The three main layers that make up the Earth's interior
Crust
The ______ is a layer of rock that forms Earth's outer skin.
Oceanic Crust
The crust beneath the ocean is called the ______ _____
Continental crust
______ ______ is the crust that forms the continents
Outer Core
The ______ ______ is a layer of molten metal that surrounds the inner core
Inner Core
The ______ ______ is a dense ball of solid metal.
YOU MIGHT ALSO LIKE...