DERIVING RELIABLE GEOLOGICAL INFORMATION FROM SEISMIC TOMOGRAPHY
To avoid such difficulties, Tarantola (Nature Physics, v. 2, pp. 492-494, 2006) suggested that seismic tomography practice be altered so as not to seek “optimal” models but rather to test specific scientific hypotheses.
We present examples, using both synthetic and real data, of artifacts that conventional seismic tomography methods can introduce, and show how they can be avoided using a hypothesis-testing approach. In particular, we show examples of “four-dimensional” seismic tomography, testing the reality of apparent temporal changes in seismic wave speeds in volcanic areas and in both natural and exploited geothermal areas.