Sunday, October 28, 2012

Earthquake Convictions in Italy 2

  The plots in the last blog may not be admissible as evidence against the individuals charged with wrong doing since they assume facts not in evidence at the time the statements were made, specifically, the existence and time of the M6.3 earthquake. Here is a new set of plots using averaging intervals of 1/3 of the anomalistic month of 27.55 days. They start at the beginning of 2002 and the time scale is in Julian years of 365.25 days.
  There doesn't appear to be much to indicate that a major earthquake is imminent. There is a decrease in the frequency of earthquakes in an interval of time and some low level earthquakes are missing. The pattern of the total energy of the earthquakes in an interval for several years before the earthquake doesn't appear to change much. The nonuniformity could be interpreted as statistical fluctuations as might be the increase in the average energy with fewer earthquakes per interval. With lower numbers one can expect greater fluctuations in the average. What may be abnormal is the low level of earthquake activity immediately prior to the time of the major earthquake which I have referred to elsewhere as a "lull." Another oddity is the disappearance of low level earthquakes which might indicate that the faults have locked up some. It's still difficult to point to anything that says there will be a major earthquake soon.
  Supplemental (Oct 28): One should probably ask if the absence of earthquakes below M2.5 from mid 2004 onward was due to a change in earthquake activity or a change in monitoring them. Would a global network charged with monitoring earthquakes worldwide reduce the sensitivity of a seismograph when there are a large number of local earthquakes or would they reduce the number reported to the system? The explanation might be relevant to the case.

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