CM's+Post+Assessment

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Using Google Maps, I found the distance from the earthquake to the LIGO station in Hanford, Washington to be 6694.87 miles, which converts into 10774.3489 kilometers.
 * 1. Use Google Maps (or Google Earth—your pick) to calculate the distance from the quake’s epicenter to LIGO.**

For the Seismic Y graph, the calcuations for the seismic wave speed would be: 6694.87mi=10774.3489km distance/time I figured the time to be around 4:13, which would make it 23 minutes time in between or 1380 seconds. 10774.3489km/1380sec=7.807km/sec
 * 2. Calculate the seismic wave speed twice, once for each of the LIGO plots shown.**

For the Seismic Z graph, the calculations for the seismic wave speed would be: On this graph, the time looked more like 4:24, which would make it 34 minutes time in between or 2040 seconds. 10774.3489km/2040sec=5.282km/sec

The seismic waves seem to have travelled fast, but I think that it would make sense, because the distance of the quake is over water. This means that the waves were p-waves, and would travel faster because they are going through water. This fits right in with the calculations that p-waves travel 5-8 kilometers per second. These two speeds fit in right along those lines.
 * 3. Comment on any difference you see between the LIGO plots, and between the wave speed estimates obtained using each plot.**

The reason that the times for these two graphs are different is because the seismometer, tiltmeter, and magnetometer have these three different sensors. They are all in independent directions, which would explain the lapse in time. Follow this [|link] to learn more about these and other tools at LIGO.

There are differences in the time, though, because there are four different types of seismic waves. The p-waves travel through water, whereas the s-waves travel through land. This can account for some difference, as well. Follow this [|link] to learn more about seismology and this [|link] to learn more about s- and p-waves specifically. I found both of these sites very informative.