Measuring Earthquakes

The video tutorial explains how seismic waves from earthquakes are detected using seismographs, which produce seismograms to help scientists determine earthquake details. It introduces the Richter scale as a method to measure earthquake strength, noting that each increase of 1.0 on the scale represents a tenfold increase in wave amplitude. The tutorial also compares the magnitudes of the 1964 Alaska earthquake and the 1989 Loma Prieta earthquake to illustrate the scale's application.

What is the primary function of a seismograph?

• To calculate the speed of tectonic plate movement

• To measure the temperature of the Earth's core

• To detect and record seismic waves

• To predict future earthquakes

What does a higher line on a seismogram indicate?

• A deeper earthquake focus

• A weaker earthquake

• A longer earthquake duration

• A stronger earthquake

How does the Richter scale measure earthquake strength?

• By the duration of the earthquake

• By the depth of the earthquake's focus

• By the amplitude of the surface waves

• By the distance from the epicenter

If an earthquake measures 8.0 on the Richter scale, how much stronger is it compared to one that measures 7.0?

• 2 times stronger

• 5 times stronger

• 10 times stronger

• 100 times stronger

Which earthquake had a magnitude of 9.0 on the Richter scale?

• The 2011 Tohoku earthquake

• The 2004 Indian Ocean earthquake

• The 1964 Alaska earthquake

• The 1989 Loma Prieta earthquake