Jessie+T.+and+Emily+A.-Earthquakes

//emily and jessie-red class//
handouts include: ~chapter 15 notes: Earthquakes and Plate Tectonics

__What is an Earthquake?__

 * 1) Shaking and vibration at the surface of the earth resulting from underground movement along a fault plane of from volcanic activity.

__What are the Causes of Earthquakes?__

 * 1) Ground can shake from; volcanoes, collapses, meteors.
 * 2) Major cause is stress builds up between two lithospheric plates.

3. Earthquakes occur when the stress along the fault planes overcome the forces of friction. When the Friction is finally overcome, the plates move and release earthquake energy.



Epicenter: point on Earth's surface directly above the focus (which is where the first movement occurs).k

__What types of earthquake waves are there?__
-travel through any material -moves rock particles back and forth -travel through solids not through liquids and gases -moves rock particles side to side -move like ripples -travel slowly -resembles waves in water
 * P waves are compressional and primary
 * S waves are shear and secondary
 * L waves are surface waves

__How do scientists locate eathquakes? What materials are used?__
different seismograms for different eathquakes
 * 1) seismograph: instrument that detects and records earthquake waves



2. seismogram: recording sheet

__Determining the distance to the earthquake's epicenter:__

 * 1) tracking used to tell how far away the earthquake epicenter is from where it was recorded
 * 2) by using graphs and other earthquakes to help you, you can find the exact spot of the earthquake

__Measuring an earthquake:__
-ground shakesc -foundation failure
 * 1) seismograms can be used to determine the strenght, magnitudem and energy produced
 * 2) __richter scale:__ measures amount of engery released by the earthquake
 * 3) __seismic moment:__ new method to determine magnitude
 * mild quakes can take down a building

4. __ground shaking:__ result of waves set in motion 5. __foundation failure:__ result in ground shaking, but the soils may become unstable or liquidy

__What kind of earthquake waves can be found inside the earth?__

 * 1) P and S waves
 * 2) in mantle, inner core, and outer core

__moho:__ mohororicic; boundary between crust and mantle (50 km) __shadow zone:__ wide belt on opposite side of focus of earthquakes
 * P and S waves reach seismograph
 * shadow zone has no waves
 * P waves only pass through the mantle