Three seismic recording stations recorded the fall. You are the
technician assigned to discover where the fall occurred and to
recover the meteorite. You have gathered the following
information:
Different types of seismic waves tend to move at different
velocities. The fastest wave is the primary wave, or compressional
wave, which is followed in time by the slower secondary wave, or
shear wave. They are affected similarly by the materials they
cross. As a result, there are relatively constant ratios between
the velocities of different pairs of seismic wave types, no matter
what kind of material they are passing through. P waves generally
travel between 5.95 and 6.75 kilometers per second in the crust,
depending on compressibility, rigidity, uniformity, and density of
the materials traversed. S waves tend to move at velocities between
2.9 and 4.0 km/sec in the crust.
From previous information you know that P-Waves travel at 6.00
kps and S-Waves travel at 4.00 kps in the area of interest.
STATION |
LOCATION |
P-WAVE ARIVAL |
S-WAVE ARIVAL |
GCG0M5 |
N39 30.840, W104
44.109 |
04:05:07.1673 |
04:05:07.4240 |
GCKPM8 |
N39 31.710, W104
47.901 |
04:05:07.2890 |
04:05:07.6065 |
GCJVMR |
N39 27.302, W104
46.119 |
04:05:07.5507 |
04:05:07.9990 |
Well, you are not allowed to actually take the fake meteorite
but there is a container under it to log your find.
There are three Sacagawea coins, one for each of the first three
teams to find the cache.
Unrealistic? Consider this: The plane impacts on the WTC towers
were recorded several hundred kilometers away. When the towers
collapsed, the impact of each floor hitting the one below it was
recorded. When flight 93 crashed in rural Pennsylvania, seismology
told the authorities that the plane was down and had crashed intact
rather than exploding while in the air. There are 16,000
permanently installed stations around the world.
You can check your answers for this puzzle on
Geochecker.com.