A student researching earthquakes has taken notes:

• Earthquakes release energy from stress along faults • The moment magnitude scale measures earthquake size • P-waves travel faster and arrive before S-waves • Seismographs detect ground motion worldwide • Early warning systems can provide seconds of advance notice

5
reading

The student wants to explain how earthquake early warning works.

A

Earthquakes release energy accumulated from stress along fault lines.

B

Early warning systems work because P-waves travel faster than destructive S-waves—detecting P-waves provides crucial seconds of warning before stronger shaking arrives.

C

The moment magnitude scale has replaced the Richter scale for measuring earthquakes.

D

Seismographs detect and record ground motion from earthquakes worldwide.

Correct Answer: B

Choice B. Faster P-waves providing warning before S-waves explains early warning.