Name: Date: Lab Period: Locating the Epicenter of an | Chegg.com - Free Printable

To solve this task, we need to fill in the Data Table by analyzing the seismograph tracings for each city. Here’s how we can do it step by step:

Step 1: Identify P-wave and S-wave Arrival Times

For each city, we need to find the times when the P-waves and S-waves arrive. The P-wave is the first wave to arrive, and the S-wave is the second.

#### Balboa Heights, Panama
- P-wave Arrival Time: Look at the first significant spike after the 15-minute mark. It appears to be around 17 minutes.
- S-wave Arrival Time: Look at the second significant spike. It appears to be around 23 minutes.

#### Boulder, Colorado
- P-wave Arrival Time: The first significant spike is around 16 minutes.
- S-wave Arrival Time: The second significant spike is around 21 minutes.

#### Mexico City, Mexico
- P-wave Arrival Time: The first significant spike is around 18 minutes.
- S-wave Arrival Time: The second significant spike is around 24 minutes.

Step 2: Calculate the Difference Between P-wave and S-wave Arrival Times

Subtract the P-wave arrival time from the S-wave arrival time for each city.

#### Balboa Heights, Panama
- Difference: 23 minutes - 17 minutes = 6 minutes

#### Boulder, Colorado
- Difference: 21 minutes - 16 minutes = 5 minutes

#### Mexico City, Mexico
- Difference: 24 minutes - 18 minutes = 6 minutes

Step 3: Determine the Distance to Epicenter

Using a P and S Travel Time Curve (which is not provided but typically available in such labs), we can find the distance to the epicenter based on the time difference. For simplicity, let's assume the following approximate distances based on typical travel time curves:

- A 5-minute difference corresponds to approximately 3000 km.
- A 6-minute difference corresponds to approximately 4000 km.

Final Data Table

| City | P-wave Arrival Time | S-wave Arrival Time | Difference Between P-wave and S-wave | Distance to Epicenter |
|-----------------|---------------------|---------------------|--------------------------------------|-----------------------|
| Balboa Heights | 17 min | 23 min | 6 min | 4000 km |
| Boulder | 16 min | 21 min | 5 min | 3000 km |
| Mexico City | 18 min | 24 min | 6 min | 4000 km |

Final Answer:
The completed Data Table is as follows:

| City | P-wave Arrival Time | S-wave Arrival Time | Difference Between P-wave and S-wave | Distance to Epicenter |
|-----------------|---------------------|---------------------|--------------------------------------|-----------------------|
| Balboa Heights | 17 min | 23 min | 6 min | 4000 km |
| Boulder | 16 min | 21 min | 5 min | 3000 km |
| Mexico City | 18 min | 24 min | 6 min | 4000 km |