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;
33 Cards in this Set
- Front
- Back
|
Definition of earthquake and main cause |
Vibration of the earth produced by the rapid release of energy.Most caused by sudden movement along a fault. |
|
|
definition of focus |
Place where the earthquake originates |
|
|
Definition of epicenter |
Place on earth’s surface above focus |
|
|
Definition of fault |
A large fracture in the earth’s crust which movement occurs |
|
|
Defintion of elastic rebound |
Sudden release of stored strain in the rocks results in movement along a fault. |
|
|
four stages of elastic rebound |
Original position Buildup of strain Slippage Strain release |
|
|
Four main causes of earthquakes |
Movement along a fault (most common) Movement plate boundary movement of magma within a volcano Volcanic explosions |
|
|
Two main earthquake belts |
Circum- pacific Mediterranean- Himalayan |
|
|
definition of seismology |
Study of earthquake waves |
|
|
definition of seismograph |
Instrument that records earthquake waves |
|
|
two types of seismic waves produced by earthquake |
surface- travel along the outer layer of the earth Body- travel through the earths interior |
|
|
two types of body waves |
p waves- expand and compress material as they pass through
s waves- shake at right angles to direction of movement |
|
|
what is stress |
The measure of the amount of force placed on an object |
|
|
what is strain |
The amount of distance an object deforms under stress |
|
|
five types of stress and draw the direction |
Compressional- shortens the body of the rock unit Tensional- lengthens the body of the rock unit Shear- material of the rock unit is divided by opposing forces Torsional- material is twisted Bending- bent into an arch or a trough |
|
|
two main methods used to measure earthquake |
Mercalli scale- measures intensity: effects on humans and structures Ritcher Scale- measures magnitude: amount of energy released |
|
|
eight measures of the Richter scale |
2.0- recorded but not felt 2.0-2.9- perceptible 3.0-3.0- felt by some 4.0-4.9- felt by most 5.0-5.9- damaging shocks 6.0-6.9- destructive in populous regions 7.0-7.9- major damage 8.0 + great to total destruction |
|
|
five factors that determine the severity of an earthquake |
Magnitude Duration Quality of structure After shock nature of material the structures are built on |
|
|
seven main side effects of earthquakes |
Fire After shock Tsunami Landslides Faulting Ground motion Liquefaction Seiches |
|
|
what provides our majority of our knowledge |
comes from earthquake waves |
|
|
two main sources of seismic waves |
Earthquakes Nuclear explosions |
|
|
two main problems in obtaining accurate travel times |
Knowing the exact location of earthquake Knowing the exact time of earthquake |
|
|
Two main areas of knowledge provided by studying of earthquakes and nuclear explosions |
Earth’s composition Earth’s structure |
|
|
Seven main characteristics of seismic waves (ridgid=rapid) (non-rigid=slow) ONLY LIST 4!!! |
Velocity depends on density and elasticity of materials being passed through Velocity increases with depth P-waves pass through all materials states (solid, liquid, gas) S-waves do not pass through liquids P-waves travel faster that s-waves Seismic waves can be refracted as they pass from one material to another |
|
|
Three main compositional layers of the earth |
Crust Mantle Core |
|
|
Five main layers of the earth based on physical properties |
Lithosphere-Crust and uppermost part of the mantle Asthenosphere-A soft, comparatively weak layer beneath the lithosphere Mesosphere-Lower mantle Outer core-Liquid iron and nickel Inner core-Solid iron and nickel |
|
|
what is geothermal gradient |
Temperature gradually increases with an increase in depth |
|
|
what is convection |
A transfer of heat by the mass movement or circulation in a substance |
|
|
what is mohorovic discontinuity |
Boundary between the crust and the mantle Crust |
|
|
five material that make up the earth |
Igneous rock Sedimentary rock Metamorphic rock Basic minerals Mineral ores |
|
|
what is mantle |
Largest zone of the earth by volume |
|
|
what is core |
Layer of the earth with the highest density Produces earth’s magnetic field |
|
|
3 physical states of matter |
solid liquid gas plasma |
