Problem Description:
The image provided is a graph titled "Earthquake P-Wave and S-Wave Travel Time." It shows the relationship between the
epicenter distance (in thousands of kilometers) and the
travel time (in minutes) for both
P-waves (primary waves) and
S-waves (secondary waves). The task is to analyze the graph and solve any related problem. Since no specific question is mentioned, I will infer a common task: determining the epicenter distance based on the given travel times for P-waves and S-waves.
---
Solution:
#### Step 1: Understand the Graph
- The graph has two lines:
- The
lower line represents the travel time of
P-waves.
- The
upper line represents the travel time of
S-waves.
- The x-axis represents the
epicenter distance in thousands of kilometers (\( \times 10^3 \) km).
- The y-axis represents the
travel time in minutes.
#### Step 2: Identify Key Points
From the graph:
- The point labeled
P corresponds to the P-wave travel time.
- The point labeled
S corresponds to the S-wave travel time.
#### Step 3: Read the Travel Times
- For the
P-wave (point P):
- The travel time is approximately
9.5 minutes.
- For the
S-wave (point S):
- The travel time is approximately
17.5 minutes.
#### Step 4: Determine the Epicenter Distance
To find the epicenter distance, we need to trace the travel times back to the x-axis:
- For the
P-wave:
- At 9.5 minutes, the corresponding epicenter distance is approximately
6.5 thousand kilometers.
- For the
S-wave:
- At 17.5 minutes, the corresponding epicenter distance is approximately
8.5 thousand kilometers.
#### Step 5: Verify Consistency
Both P-waves and S-waves should give the same epicenter distance because they originate from the same earthquake. However, due to measurement or graphical approximation, there might be slight differences. In this case:
- The P-wave suggests an epicenter distance of
6.5 thousand kilometers.
- The S-wave suggests an epicenter distance of
8.5 thousand kilometers.
Given that P-waves are generally more reliable for determining distances, we can use the P-wave value as the primary estimate.
#### Final Answer:
The epicenter distance is approximately:
\[
\boxed{6.5 \text{ thousand kilometers}}
\]
---
Explanation:
1.
P-waves vs. S-waves: P-waves travel faster than S-waves, so their travel times are shorter for the same distance. This is why the P-wave line is below the S-wave line on the graph.
2.
Graph Reading: Accurate reading of the graph requires careful alignment with the grid lines to estimate both travel times and distances.
3.
Reliability: While both P-waves and S-waves can be used, P-waves are typically more reliable for determining distances due to their higher speed and less dispersion.
If you have a specific question or need further clarification, feel free to ask!
Parent Tip: Review the logic above to help your child master the concept of earthquake p wave and s wave travel time worksheet.
