Question

if we know the s - p arrival time, we can refer to published charts to determine the distance to the earthquakes epicenter. what is distance to the epicenter if s wave arrives 3.5 minutes after p wave? (careful - the #2 and #3 are only from the example in the book. you are looking for the distance at which the difference between the p - and s - curves equals the time interval you found above. be sure to use the bottom scale for miles or figure 5.14 in your book) 1800 miles 1500 miles 1000 miles 2500 miles

Explanation:

Step1: Locate time - interval on graph

Find the point on the graph where the vertical distance (time - difference) between the S - wave curve and the P - wave curve is 3.5 minutes.

Step2: Read distance value

Read the corresponding distance value on the x - axis (distance from epicenter in miles) at that point. By referring to a standard S - P travel - time graph (similar to the one provided), when the S - P time interval is 3.5 minutes, the distance to the epicenter is approximately 2500 miles.

Answer:

2500 miles