Question

hand draw in this space or click here to select edit to use the drawing tool. label ( ) the first p - wave and the first s - wave. estimate the time difference ($\delta t$), and then use your graph to find the distance to the epicenter. (as in the gizmo, each vertical line represents 50 seconds.)

Explanation:

Step1: Identify first P - wave and S - wave

Locate the first arrival of the P - wave (faster wave) and S - wave (slower wave) on each seismogram.

Step2: Measure time difference ($\Delta t$)

Count the number of 50 - second intervals between the first P - wave and first S - wave arrival. Multiply the number of intervals by 50 s to get $\Delta t$.

Step3: Use time - distance relationship

There is a known relationship between the time difference $\Delta t$ and the distance to the epicenter. Usually, this relationship is based on empirical or theoretical models for seismic wave propagation. For example, if we have a pre - established graph or formula that relates $\Delta t$ to distance, we substitute the measured $\Delta t$ value to find the distance.

Answer:

Since no actual seismogram data is provided to measure $\Delta t$ and no specific time - distance relationship formula is given, we cannot provide numerical values for $\Delta t$ and distance. But the general process is as described above.