“ringwoodite” more complicated waves, too
Post on 15-Jan-2016
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“ringwoodite”
More complicated waves, too
Real life example
• At 23:24:50.6 GMT, on Nov. 22 2001, an earthquake occurred in Fiji (southwest Pacific)
• The P wave from this earthquake was recorded in Pasadena, CA at 23:36:50.7 GMT
• Therefore the observed travel time is 720.10 s• The distance between the Fiji earthquake and
the seismometer in Pasadena is 78.8o (8762 km).
• The theoretical (expected) travel time for a P wave at this distance is 721.25 s.
• Therefore the travel time residual is -1.15 seconds
Seismic stations from Fiji to the Tonga trench
Time residuals from Fiji across the Tonga trench
Inferred structure in one slice across the Tonga trench
Fiji Tonga
Pacific plate
earthquakes
slower P waves faster P waves
IMap of inferred structure 25 km down
140 km down
Earthquakes used to do global tomography and where the seismic stations are
A few random tomographic slices
Comparison of different tomographic reconstructions
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