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 * 1. Use Google Maps (or Google Earth—your pick) to calculate the distance from the quake’s epicenter to LIGO.**

The distance from the quake's epicenter to LIGO is approximately 10,742.68 kilometers.


 * 2. Calculate the seismic wave speed twice, once for each of the LIGO plots shown.**

According to the Y PLOT, the earthquake occured approximately 10742 kilometers away, and took about 24 minutes and 20 seconds (1460 seconds) to be detected by the LIGO censors, it can be calculated that the waves traveling were moving at approximately 7.36 kilometers per second.



According to the Z PLOT, the earthquake occured approximately 10742 kilometers away and took about 23 minutes (1380 seconds) to be detected by the LIGO censors, it can be calculated that the waves traveling were moving at approximately 7.79 kilometers per second.


 * 3. Comment on any difference you see between the LIGO plots, and between the wave speed estimates obtained using each plot.**

The two graphs are different from each other in that they both have a different time recorded as the start of the earthquake. In the Y PLOT, the starting time of the earthquake is approximately 4:15 while the Z PLOT reads approximately 4:08. This probably because the Y and Z plots come from two different censors. The LIGO center has three censors that point in different directions and are labelled X, Y, and Z. Therefore it is reasonable to believe that the censors detected the waves at different times because they received the waves from different directions. So when the earthquake occured, the waves detected by the Z censor travelled a shorter distance than that of the waves detected by the Y censor. This could have also been caused by the matter (solid earth or water) which the waves traveled through, because waves travel faster when they travel through liquid than they do when they travel through solid.

