abstract
activity
amplituda
background
black
catastrophe
charter
circle
concrete
curva
damage
danger
detector
diagram
disaster
display
earth
earthquake
frequency
grapher
grid
illustration
increased
instrument
isolated
machina
meter
natura
needle
paper
peak
polygraph
pulse
quake
record
rejection
richter
ruin
scala
seismic
seismograph
seismology
seismometer
stylus
technology
the vibration
truth
wave