Help on locating S-P intervals? Epicenter questions too?

Question

I'm doing an online quiz, and I can't seem to figure this part out.

http://www.sciencecourseware.org/VirtualEarthquake/php/ComputeDistance.php

Can anyone tell me/walk me through on how to find the KM of how far the epicenter is and the S-P interval?? Don't give me the answer, I just want to figure out how to do it, it's impossible for m. -_- Thanks!

Answer 1

I am doing this on another page so I can walk you through this.

I chose to do the San Francisco area.
Just read the directions and plug in your answers to find the epicenters. On the graph there are two sets of (swiggles) what you do is measure the first (swiggle) (p-wave) until you hit the secondary wave. on the graph. the graph starts from 0 so you measure from zero till you hit the secondary wave this measures the time of the p-wave.

there are three graphs to read.
1st graph eureka CA
2nd graph Elko NV
3rd graph Las Vagas NV

the first graph I measured (time)
49
the second graph I measured (time)
72
The third graph I measured (time)
64

The next step is to find the epicenter you do this by plugging in these numbers to the epicentral distance graph http://www.sciencecourseware.org/VirtualEarthquake/php/ComputeDistance.php

The first epicentral distance I measured
478
2nd
702
3rd
622

then I hit enter to find epicenter
http://www.sciencecourseware.org/VirtualEarthquake/php/TheirCircles.php

Now we will measure the magnitude
http://www.sciencecourseware.org/VirtualEarthquake/php/DoRichter.php

http://www.sciencecourseware.org/VirtualEarthquake/php/DoRichter3.php

you measure the s-wave's highest point on the seismograph
you measure all three graphes amplitude as well.

1st measure is 275
2nd measure is 55
3rd measure is 98

you hit enter then measure the richtermeter
I measured 7.1 magnitude all together and got it correct.

Good luck!

I did this one for you only to walk you through this one. There are 2 others is you want the challenge.

Answer 2

I think I would determine best answer by the actual answer. If there were more than one really good answers then I would choose a contact. I know most best answers go to contacts but I would look at giving best answers as a way to make even more friends and contacts. Nice question. What is really hilarious is when people have more than one account and award themselves the best answers. They think others don't know but I just laugh at them.