Test your knowledge with these top questions!
How much bigger are shaking waves for each whole-number Richter step?
The scale is logarithmic, so a magnitude 6 wiggle measures ten times taller than magnitude 5.
Which Han inventor built the first known earthquake detector around 132 AD?
Zhang Heng's bronze vessel used a pendulum and dragon figures that dropped balls to show the quake direction.
Which scale now rates very large earthquakes instead of the Richter scale?
Moment magnitude matches Richter for small quakes but stays accurate for the largest ones.
What does the Richter scale measure?
Richter readings come from the height of wiggles recorded by a seismograph.
What ground-shaking events do seismographs mainly detect and record?
Earthquake waves shake the ground beneath a seismograph, and the instrument draws that motion as wavy lines for study.
Which scientist created the Richter scale in 1935?
Richter developed the scale with Beno Gutenberg at Caltech to compare California quakes.
Why does the heavy mass inside a classic seismograph stay nearly still?
The frame moves with the shaking ground while inertia holds the suspended mass steady, and a pen traces the difference.
What name do scientists give the wavy record drawn by a seismograph?
A seismogram plots ground motion over time, so taller wiggles generally mean stronger shaking at that station.
Earthquakes occur most frequently along the Pacific ocean boundary known as the:
The Ring of Fire hosts about 90 percent of all earthquakes due to active subduction zones around the Pacific plate.
Seismic S-waves stop moving when they encounter Earth's:
Because shear waves cannot travel through liquids, S-waves stop at Earth's liquid outer core, creating a shadow zone.