FAQs - Measuring Earthquakes
- Where can I buy a Richter scale?
- Why are there often different magnitudes reported for the same earthquake?
- What is moment magnitude?
- What are the earthquake magnitude classes?
- When was the first instrument that actually recorded an earthquake?
- What is a P wave? An S wave?
- What does an earthquake look like?
- What is intensity? What is the Modified Mercalli Intensity Scale?
- What is the difference between intensity scales and magnitude scales?
- What is acceleration, velocity, and displacement?
- What is spectral acceleration?
- What are those beachball figures?
- How much energy is released in an earthquake?
- What are UTC and GMT (in reference to the time of an EQ)?
- What does it mean that the earthquake occurred at a depth of 0 km?
- How are earthquakes recorded? How are earthquakes measured? How is the magnitude of an earthquake determined?
- What are the different magnitude scales, and why are there so many?
- How do you give a Richter magnitude to earthquakes that occurred prior to the scale?
- What was the duration of the earthquake? Why don't you report the duration of each earthquake? How does the duration affect the magnitude?
- How do seismologists locate an earthquake?