RM-+LIGO+Aug+2006+Bluestone

Back to RM's August 2006 Earthquake 



code Date      Time             Lat       Lon  Depth   Mag Magt  Nst Gap  Clo  RMS  SRC   Event ID -- 2006/08/01 02:16:30.84 -18.1120 -174.5960 66.40  5.00   Mb   46          1.34  NEI 200608014002 2006/08/01 03:04:43.15 28.3260  104.7360  35.00  4.40   Mb   29          1.13  NEI 200608014004 2006/08/01 03:05:36.47 37.6530   74.5950  39.20  4.50   Mb   16          0.89  NEI 200608014005

code As you can see, the three earthquakes can be viewed on this single recording from LIGO. How do we know this?

Well: The distance from 1st one is approximately 5,931.16 km, located in the Pacific Ocean. Now, the waves reaching LIGO would be p-waves, because the the seismic waves would be travelling through water. P-waves have a speed of about 5-8 km/sec. Thus, it produces a range.

5,931.16 km / 5 km/sec = 1,186.232 sec

5,931.16 km / 8 km/sec = 741.395 sec

1,186.232 sec / 60 sec x 1 min. = 19.77 min

741.395 sec / 60 sec x 1 min. = 12.36 min

So, the quake would appear at LIGO anytime between 2:29 to 2:36, pretty consistent with the graph. Judging the graph, I expect the waves traveled about 5-6 km/sec.

The distance from 2nd earthquake is approximately 10,667.28 km. The waves reaching LIGO would have to be both p- and s-waves, as the seismic waves must travel through sea and land. P-waves, as mentioned, have a speed of about 5-8km, while s-waves have a speed of about 3-5 km/sec.

10,66.28 km / 5 km/sec= 2133.456 sec
 * //P-wave equations//**

10,667.28 km / 8 km/sec = 1333.41 sec

2133.456 sec / 60 sec x 1 min. = 35.5576 min.

1333.41 sec / 60 sec = 22.2235 min.

//**S-wave equations**// 10,667.28 km / 3 km/sec = 3555.76 sec

10,667.28 km / 5 km/sec = 2133.456 sec.

3555.76 sec / 60 sec x 1 min. = 59.26 min.

2133.456 sec / 60 sec x 1 min. = 35.5576 min.

Thus, the time that the p-waves would have been registered at LIGO would be between 3:27 and 3:40. Since the wave is registered at LIGO being closer to 3:40, I expect the p-wave to be travelling between 5-6 km/sec. As for the s-waves, they are predicted to register at LIGO between 3:40 and 4:04. It seems that it came in at right about 4:04. Therefore, I expect that the s-wave travelled around 3 km/sec.

Now, the distance from 3rd earthquake was approximated to be 10,637.38 km from LIGO, as told using the Google Earth ruler tool. Again, with this earthquake, the seismic waves had to travel through land and water. Thus, there are p-waves and s-waves, with corresponding speeds of about 5-8 km/sec and 3-5 km/sec.

10,637.38 km / 5 km/sec = 2127.476 sec.
 * //P-wave equations//**

10,637.38 km / 8 km/sec = 1329.6725 sec.

1 min. / 60 sec x 2127.476 sec. = 35.46 min.

1 min. / 60 sec x 1329.6725 sec. = 22.16 min.

10,637.38 km / 3 km/sec = 3545.79 sec.
 * //S-wave equations//**

10,637.38 / 5 km/sec km = 2127.476 sec.

1 min. / 60 sec x 3545.79 sec. = 59.0965 min.

1 min. / 60 sec. x 2127.476 sec. = 35.46 min.

Therefore, the p-waves should reach LIGO between 3:28 and 3:41. The s-waves should reach LIGO between 3:41 and 4:05. This correlates pretty well with the graph. In fact, it presents some very interesting thoughts. The latter two earthquakes were the farthest away from LIGO, and within a minute of each other. Thus, I suspect that second and the highest peak is the combined effect of these two earthquakes. It makes sense because it is higher than the first earthquake's peak due to the combined effect. However, it is no too high (such as twice the size of the first earthquake's peak) because the latter two earthquakes were about 10,600 miles away from LIGO, about 5,000 miles farther than the first earthquake.