Final answer:
Seismographs record seismic waves (P-waves and S-waves), not radio waves, from earthquakes. They help determine the distance to an earthquake's epicenter by comparing the arrival times of these two types of waves, which travel at different speeds.
Step-by-step explanation:
The statement that a seismograph produces a graph-like representation of the radio waves released in an earthquake is false. Seismographs are instruments used to detect and record the vibrations from earthquakes. They do not measure radio waves; instead, they record seismic waves, which include P-waves (primary waves) and S-waves (secondary waves), both of which are types of mechanical waves traveling through the Earth's interior. The seismograph produces a seismogram, which graphs the motion of seismic waves, not radio waves.
When an earthquake occurs, seismographs measure the arrival times of these P-waves and S-waves. Due to different propagation speeds, the P-waves arrive before the S-waves. By analyzing the time difference between the arrival of these two types of waves, scientists can calculate the distance to the earthquake's epicenter. If P-waves travel at 7.20 km/s and S-waves at 4.00 km/s, and the precision of the measurement is 0.100 seconds, the exact distance can have a certain degree of uncertainty, which could be crucial when detecting seismic events like underground nuclear tests. Identifying such tests relies on the precision of seismographs and the known speeds of seismic waves through various Earth materials.