Earthquakes Flashcards
Earthquakes
Shaking/vibration of the earth’s crust
Focus
place in the earth’s crust where earthquake happens
Epicenter
◍ area on surface that directly above the focus
◍ shockwaves hit here first
Shockwave
◍ Seismic waves/tremors that radiate out
◍ Spread out from the focus
seismologists
study of earthquakes
Seismographs
machines that measure the magnitude of an earthquakes
Aftershock
Waves that occur after the main shock of the earthquake
SHallow focus earthquakes
◍ close to surface
◍ most common and most dangerous
◍caused by subduction
Deep focus earthquake
◍ rarely cause surface damage
◍ located at subduction zones as one plate moves beneath the other
types of waves on seismograph
◍ P waves
◍ S waves
◍ Surface waves
Primary/P Waves
◍ fastest
◍ travel through molten material
Secondary/S Waves
◍ slower
◍ travel through rock
Surface waves
◍ slowest
◍ Travel on surface and causes movement
Richter scale
◍ measures magnitude
◍ open-ended scale
◍ each point increases by 10 power
Mercalli scale
◍ measures damage
◍ !2 points I-XII
◍ I meaning no damage
◍ XII meaning total devestation
Earthquake prediction
◍ Seismic activity
◍ Radon gas
◍ Unusual animal behavior
◍ level of water in wells
factors that determine damage caused
◍ time of day
◍ magnitude
◍ depth of focus
◍ population in area
◍ terrain
◍ wealth of area
◍ geology in area [unconsolidated area]
short term effects
◍ death and destruction
◍ landslides
◍ liquefaction
long term effects
◍ outward migration
◍ disease
◍ economic slowdown
Liquefaction
◍ unconsolidated material
◍ Sand and gravel mixes with water
◍ turn to liquid mud
◍ can’t support structure causing them to fall
Limiting damage
◍ Flexible columns
◍ cross beams
Emergency aid
◍ aid given asap after a natural disaster to ensure survival
◍ food,water,blankets
Development Aid
◍ Given over a long period of time
◍ machinery,teachers and engineers
Tsunami
◍ Series of large waves
◍ formed by earthquakes,volcanic eruptions,landslides on ocean floor
