Shared Flashcard Set

Details

Chapter 8 Earthquakes
Earth/Space Science
54
Science
11/21/2011

Term
 Earthquake
Definition
 vibration of Earth produced by the rapid release of energy
Term
 Focus
Definition
 Place wher waves are released from. "point" of earthquake
Term
 Faults
Definition
 break in rock where movement has occured
Term
 Where do Earthquakes usually happen?
Definition
 along fault lines
Term
 What is the name of the fault in CA? Describe it.
Definition
 San Andreas Fault. it is several large faults and many fractures
Term
 How do rocks behave when it is under stress?
Definition
 it bends, storing elastic energy
Term
 What is placing strain on the rocks?
Definition
 slippage
Term
 What builds up in the rock?
Definition
 energy
Term
 Elastic Rebound
Definition
 "spring back" of a rock
Term
 foreshocks
Definition
 small earthquake before a major one
Term
 afterschocks
Definition
 small earthquake after a major one
Term
 How strong are aftershocks? Can they cause damage?
Definition
 1. much weaker than the main earthquake 2. yes, because building are already weak
Term
 Why do scientists monitor foreshocks?
Definition
 To predict/plan for future earthquakes
Term
 What are 2 zones with alot of earthquake activity?
Definition
 1. subduction zones 2. ocean ridges
Term
 Intensity
Definition
 meausure of earthquake shaking
Term
 magnitude
Definition
 amount of energy released at the source of an earthquake
Term
 Modified Mercali Scale
Definition
 estimates strength of earthquake. based on severity of ground shaking, population, building design
Term
 Richter Scale
Definition
 estimates the relative size of the earthquake. based on seismic waves. uses seismograph
Term
 1. How many times increase in Wave Amplitude is the earthwuake per increase in number? 2. How much increase is Energy is each unit.
Definition
 1. 10x in amplitude 2. 32x in energy
Term
 MomentMagnitude
Definition
 more precise way to meausure earthqueaks. calculated using amplitude and other factors. (more precise)
Term
 How does ground shaking move?
Definition
 the energy released by an earthquake travels along the surface
Term
 What factors affect damage?
Definition
 1. intensity 2. where the structure is built 3. duration of vibrations 4. design of structure
Term
 What kind of ground material causes the most damage?
Definition
 loose sediment/sand
Term
 Liquefication
Definition
 to make the ground fluid
Term
 Tsunami. What causes one? what is the first warning?
Definition
 large destructive waves. caused by vertical displacement on an ocea floor fault. first warning is rapid water withdrawl.
Term
 fault creep
Definition
Term
 stick slip motion
Definition
 locked behavior followed by slippage
Term
 seismograph
Definition
 instument that records seismic waves
Term
 seismogram
Definition
 info collected from a seismograph
Term
 How does a seismograph work?
Definition
 there is a stick attached to bedrock. hanging from the stick is a rock & pen. When the ground moves, the rock moves the pen and it records motions.
Term
 epicenter
Definition
 the location on the surface directly above the focus/center of earthquake
Term
 How does the interval between P and S waves reflect the distance to the epicenter?
Definition
 greater the distance between the P and S wave = greater the distance to the epicenter
Term
 Surface Waves
Definition
 travels through outer layer. moves up, down and side to side. arrives 3rd
Term
 Body Wave- Primary (P Wave)
Definition
 travels theough interior. slinky waves. Moves through everything. arrives 1st
Term
 Body Wave- Secondary (S Wave)
Definition
 travels through interior. transverse wave motion. moves through solids only. arrives 2nd.
Term
 How do you locate the epicenter on an earthquake?
Definition
 seismogram- look at P & S waves and determine the time difference between them look at time travel graph to determine distance between station and earthquake need 3 stations find distances from stations A B and C draw circles (with proper radius) around each station find the point where they all meet.
Term
 How many stations do you need to locate the direction of an epicenter?
Definition
 3 stations
Term
 Is there a relationship between earthquakes and plate boundaries?
Definition
 earthquakes happen more by plate boundaries
Term
 Why do fires erupt after earthquakes?
Definition
 pipes and electrical wires are damaged
Term
 To be accepted, what do short range predictions require?
Definition
 to be reliable and accurate
Term
 what is the time frame for a long range forecast? Why are they useful?
Definition
 30-100 years or more. useful: so you can prepare
Term
 How deep can one dig into earths interior?
Definition
 8 miles. 1/500th of the way
Term
 What is used as "x-rays" to see the interior of earth?
Definition
 seismic waves
Term
 What happens to seismic waves as they travel through the interior?
Definition
 they are reflected, refracted and diffracted as they go through Earth's interior.
Term
 How can the speed of waves give info?
Definition
 they can help determine the kind of rock inside earth & how hot it is
Term
 Moho
Definition
 boundary between the crust and the mantle
Term
 what is the difference between longitudinal waves and transverse waves?
Definition
 [image]
Term
 more amplitude equals _______
Definition
 more energy
Term
 waves that require a medium are _____. Three types of those waves are ______, _______ and _______.
Definition
 waves that require a medium are Mechanical Waves. Three types of those waves are sound, seismic and ocean.
Term
 waves that can go through empty space are ______. 2 examples of those are ______ and _______.
Definition
 waves that can go through empty space are electromagnetic waves. 2 examples of those are ultraviolet (UV) rays and infared (IR) waves
Term
 What is the EM spectrum from low frequency ---> high frequency
Definition
 radio -> micro -> IR -> visible -> UV -> x-rays -> gamma
Term
 describe the Modified Mercali Scale.
Definition
 Intensity Scale. qualitive observations. least precise. based on peoples reactions.
Term
 describe the Richter scale
Definition
 quanititave observation. based on wave amplitude and log scale. (amplitude x10 and energy x32)
Term
 Moment Magnitude Scale
Definition
 quanititive observations. most precise. based on more than 1 meausurement.
Supporting users have an ad free experience!