| Like bats using echolocation to navigate through the night, geophysicists rely on seismic waves for information on the Earth's deep interior. |
| Many countries around the world have seismographic networks that monitor and record seismic waves. |
| Just as seismic waves travel through Earth, infrasonic waves travel through the air. |
| For three years, the seismometers recorded how seismic waves from hundreds of earthquakes worldwide bounced through the mantle. |
| At the time, seismographs in western Europe recorded seismic waves from the blast. |
| The scientists compared the time it took seismic waves generated by nearly identical earthquakes to travel through the Earth's inner core. |
